Prospective Assessment of Bone Metabolism Biomarkers and Survival in Metastatic Castration-resistant Prostate Cancer Patients Treated with Radium-223: The PRORADIUM Study

BACKGROUND

Radium-223 is an active therapy option for bone metastatic castration-resistant prostate cancer (mCRPC). The lack of adequate biomarkers for patient selection and response assessment are major drawbacks for its use.

OBJECTIVE

To assess the prognostic value of bone metabolism biomarkers (BMBs) in ra-223-treated mCRPC patients.

DESIGN, SETTING, AND PARTICIPANTS

A prospective cohort study of mCRPC patients treated with Ra-223 (PRORADIUM study: NCT02925702) was conducted.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The main objective of the study was to evaluate the association between high (≥median) baseline values in at least three bone formation (bone alkaline phosphatase [BAP] and C-terminal type-I collagen propeptide) and bone resorption (N-terminal telopeptide and pyridinoline) biomarkers, and survival. The independent prognostic value of each BMB was also assessed. The association with time to radiographic, clinical, and prostate-specific antigen (PSA) progression; time to skeletal-related events; and PSA response were secondary objectives. Multivariable (MV) Cox-regression models were evaluated.

RESULTS AND LIMITATIONS

A total of 169 patients were included. Of the patients, 70.4% received Ra-223 in second/third line; 144 (85.2%) were Eastern Cooperative Oncology Group 0-1, 126 (74.6%) were in pain, and 80 (47.5%) had more than ten bone metastases. Sixty-seven (39.6%) patients had elevation in at least three BMBs. The median overall survival was 12.1 mo (95% confidence interval [CI]: 10-14.7). No association was observed with other treatment-related secondary outcome parameters. Patients with high values in three or more BMBs had significantly worse survival (9.9 vs 15.2 mo; hazard ratio [HR]: 1.8 [95% CI: 1.3-2.5]; p < 0.001) in the univariate analysis, but not independent in the MV analysis (HR: 1.33; 95% CI: 0.89-2; p = 0.181). High baseline BAP was the only biomarker associated with survival in the MV model (HR: 1.89; 95% CI: 1.28-2.79; p = 0.001). Addition of BAP to the MV clinical model increased the area under the receiver operating characteristic curve 2-yr value from 0.667 to 0.755 (p = 0.003).

CONCLUSIONS

Biomarkers of bone formation, especially BAP, have prognostic value in mCRPC patients treated with radium-223. Its predictive value remains to be assessed, ideally in prospective, adequately powered, randomised clinical trials.

PATIENT SUMMARY

In this study, we evaluate the role of bone metabolism biomarkers to help improve the use of radium-223 as therapy for advanced prostate cancer. We found that bone alkaline phosphatase may be a suitable tool.

Phase II trial of afatinib in patients with advanced urothelial carcinoma with genetic alterations in ERBB1-3 (LUX-Bladder 1)

BACKGROUND

Preclinical and early clinical data suggest that the irreversible ErbB family blocker afatinib may be effective in urothelial cancers harbouring ERBB mutations.

METHODS

This open-label, phase II, single-arm trial (LUX-Bladder 1, NCT02780687) assessed the efficacy and safety of second-line afatinib 40 mg/d in patients with metastatic urothelial carcinoma with ERBB1-3 alterations. The primary endpoint was 6-month progression-free survival rate (PFS6) (cohort A); other endpoints included ORR, PFS, OS, DCR and safety (cohorts A and B). Cohort A was planned to have two stages: stage 2 enrolment was based on observed antitumour activity.

RESULTS

Thirty-four patients were enroled into cohort A and eight into cohort B. In cohorts A/B, PFS6 was 11.8%/12.5%, ORR was 5.9%/12.5%, DCR was 50.0%/25.0%, median PFS was 9.8/7.8 weeks and median OS was 30.1/29.6 weeks. Three patients (two ERBB2-amplified [cohort A]; one EGFR-amplified [cohort B]) achieved partial responses. Stage 2 for cohort A did not proceed. All patients experienced adverse events (AEs), most commonly (any/grade 3) diarrhoea (76.2%/9.5%). Two patients (4.8%) discontinued due to AEs and one fatal AE was observed (acute coronary syndrome; not considered treatment-related).

CONCLUSIONS

An exploratory biomarker analysis suggested that basal-squamous tumours and ERBB2 amplification were associated with superior response to afatinib.

CLINICAL TRIAL REGISTRATION

NCT02780687.

Prevalence of immune-related adverse events and anti-tumor efficacy in advanced/metastatic urothelial carcinoma following immune-checkpoint inhibitor treatment

PURPOSE

We evaluated the prevalence of immune-related adverse events and anti-tumor efficacy in advanced/metastatic urothelial carcinoma following immune-checkpoint inhibitors (ICIs) treatment.

METHODS

We conducted a multicenter retrospective study of patients with advanced/metastatic urothelial carcinoma treated with ICIs in four Spanish institutions. irAEs were classified using Common Terminology Criteria for Adverse Event (CTCAE) v.5.0 guidelines. The primary endpoint was overall survival (OS). Other endpoints were overall response rate (ORR) and progression-free survival (PFS). irAEs were evaluated as a time-dependent covariate to avoid immortal time bias.

RESULTS

A total of 114 patients were treated with ICIs between May 2013 and May 2019, 105 (92%) of whom received ICIs as monotherapy. irAEs of any grade were experienced in 56 (49%) patients and 21 (18%) patients had grade ≥ 3 toxicity. The most frequent irAEs were gastrointestinal and dermatological toxicities, reported in 25 (22%) and 20 (17%) patients, respectively. Patients with grade 1-2 irAEs had significantly longer OS compared to those without grade 1-2 irAEs (median 18.2 vs. 8.7 months, HR = 0.61 [95% CI 0.39-0.95], p = 0.03). No association with efficacy was observed for patients with grade ≥ 3 irAEs. No difference in PFS was observed after adjusting for the immortal time bias. ORR was higher in patients who developed irAEs (48% vs 17%, p < 0.001).

CONCLUSIONS

Our findings suggest that development of irAEs was associated with higher ORR, and patients who developed grade 1-2 irAEs had longer OS. Prospective studies are necessary to confirm our findings.

Atezolizumab plus Magrolimab, Niraparib, or Tocilizumab versus Atezolizumab Monotherapy in Platinum-Refractory Metastatic Urothelial Carcinoma: A Phase Ib/II Open-Label, Multicenter, Randomized Umbrella Study (MORPHEUS Urothelial Carcinoma)

PURPOSE

The MORPHEUS platform was designed to identify early efficacy signals and evaluate the safety of novel immunotherapy combinations across cancer types. The phase Ib/II MORPHEUS-UC trial (NCT03869190) is evaluating atezolizumab plus magrolimab, niraparib, or tocilizumab in platinum-refractory locally advanced or metastatic urothelial carcinoma (mUC). Additional treatment combinations were evaluated and will be reported separately.

PATIENTS AND METHODS

Patients had locally advanced or mUC that progressed during or following treatment with a platinum-containing regimen. The primary efficacy endpoint was investigator-assessed objective response rate (ORR). Key secondary endpoints included investigator-assessed progression-free survival (PFS) and overall survival (OS). Safety and exploratory biomarker analyses were also conducted.

RESULTS

Seventy-six patients were randomized to receive either atezolizumab plus magrolimab (n = 16), atezolizumab plus niraparib (n = 15), atezolizumab plus tocilizumab (n = 15), or atezolizumab monotherapy (control; n = 30). No additive benefit in ORR, PFS, or OS was seen in the treatment arms versus the control. The best confirmed ORR was 26.7% with atezolizumab plus magrolimab, 6.7% with atezolizumab plus niraparib, 20.0% with atezolizumab plus tocilizumab, and 27.6% with atezolizumab monotherapy. Overall, the treatment combinations were tolerable, and adverse events were consistent with each agent's known safety profile. Trends were observed for shrinkage of programmed death-ligand 1-positive tumors (atezolizumab, atezolizumab plus magrolimab, atezolizumab plus tocilizumab), inflamed tumors, or tumors with high mutational burden (atezolizumab), and immune excluded tumors (atezolizumab plus magrolimab).

CONCLUSIONS

The evaluated regimens in MORPHEUS-UC were tolerable. However, response rates for the combinations did not meet the criteria for further development in platinum-experienced locally advanced or mUC.

Results from a Phase 1b/2 Study of Ibrutinib Combination Therapy in Advanced Urothelial Carcinoma

Ibrutinib is a first-in-class Bruton's tyrosine kinase inhibitor approved for the treatment of various B-cell malignancies and chronic graft-versus-host disease. We evaluated the safety and efficacy of ibrutinib, alone or combined with standard-of-care regimens, in adults with advanced urothelial carcinoma (UC). Once-daily ibrutinib was administered orally at 840 mg (single-agent or with paclitaxel) or at 560 mg (with pembrolizumab). Phase 1b determined the recommended phase 2 dose (RP2D) of ibrutinib, and phase 2 assessed progression-free survival (PFS), overall response rate (ORR), and safety. Thirty-five, eighteen, and fifty-nine patients received ibrutinib, ibrutinib plus pembrolizumab, and ibrutinib plus paclitaxel at the RP2D, respectively. Safety profiles were consistent with those of the individual agents. The best-confirmed ORRs were 7% (two partial responses) with single-agent ibrutinib and 36% (five partial responses) with ibrutinib plus pembrolizumab. Median PFS was 4.1 months (range, 1.0-37.4+) with ibrutinib plus paclitaxel. The best-confirmed ORR was 26% (two complete responses). In previously treated patients with UC, ORR was higher with ibrutinib plus pembrolizumab than with either agent alone (historical data in the intent-to-treat population). ORR with ibrutinib plus paclitaxel was greater than historical values for single-agent paclitaxel or ibrutinib. These data warrant further evaluation of ibrutinib combinations in UC.

Association of the Time to Immune Checkpoint Inhibitor (ICI) Initiation and Outcomes With Second Line ICI in Patients With Advanced Urothelial Carcinoma

BACKGROUND

Early progression on first-line (1L) platinum-based therapy or between therapy lines may be a surrogate of more aggressive disease and poor outcomes in advanced urothelial carcinoma (aUC), but its prognostic role regarding immune checkpoint inhibitor (ICI) response and survival is unclear. We hypothesized that shorter time until start of second-line (2L) ICI would be associated with worse outcomes in aUC.

PATIENTS AND METHODS

We performed a retrospective multi-institution cohort study in patients with aUC treated with 1L platinum-based chemotherapy, who received 2L ICI. Patients receiving switch maintenance ICI were excluded. We defined time to 2L ICI therapy as the time between the start of 1L platinum-based chemotherapy to the start of 2L ICI and categorized patients a priori into 1 of 3 groups: less than 3 months versus 3-6 months versus more than 6 months. We calculated overall response rate (ORR) with 2L ICI, progression-free survival (PFS) and overall survival (OS) from the start of 2L ICI. ORR was compared among the 3 groups using multivariable logistic regression, and PFS, OS using cox regression. Multivariable models were adjusted for known prognostic factors.

RESULTS

We included 215, 215, and 219 patients in the ORR, PFS, and OS analyses, respectively, after exclusions. ORR difference did not reach statistical significance between patients with less than 3 months versus 3-6 months versus more than 6 months to 2L ICI. However, PFS (HR 1.64; 95% CI 1.02-2.63) and OS (HR 1.77; 95% CI 1.10-2.84) was shorter among those with time to 2L ICI less than 3 months compared to those who initiated 2L ICI more than 6 months.

CONCLUSION

Among patients with aUC treated with 2L ICI, time to 2L ICI less than 3 months was associated with lower, but not significantly different ORR, but shorter PFS and OS compared to 2L ICI more than 6 months. This highlights potential cross resistance mechanisms between ICI and platinum-based chemotherapy.

Association of prior local therapy and outcomes with programmed-death ligand-1 inhibitors in advanced urothelial cancer

OBJECTIVES

To compare clinical outcomes with programmed-death ligand-1 immune checkpoint inhibitors (ICIs) in patients with advanced urothelial carcinoma (aUC) who have vs have not undergone radical surgery (RS) or radiation therapy (RT) prior to developing metastatic disease.

PATIENTS AND METHODS

We performed a retrospective cohort study collecting clinicopathological, treatment and outcomes data for patients with aUC receiving ICIs across 25 institutions. We compared outcomes (observed response rate [ORR], progression-free survival [PFS], overall survival [OS]) between patients with vs without prior RS, and by type of prior locoregional treatment (RS vs RT vs no locoregional treatment). Patients with de novo advanced disease were excluded. Analysis was stratified by treatment line (first-line and second-line or greater [second-plus line]). Logistic regression was used to compare ORR, while Kaplan-Meier analysis and Cox regression were used for PFS and OS. Multivariable models were adjusted for known prognostic factors.

RESULTS

We included 562 patients (first-line: 342 and second-plus line: 220). There was no difference in outcomes based on prior locoregional treatment among those treated with first-line ICIs. In the second-plus-line setting, prior RS was associated with higher ORR (adjusted odds ratio 2.61, 95% confidence interval [CI]1.19-5.74]), longer OS (adjusted hazard ratio [aHR] 0.61, 95% CI 0.42-0.88) and PFS (aHR 0.63, 95% CI 0.45-0.89) vs no prior RS. This association remained significant when type of prior locoregional treatment (RS and RT) was modelled separately.

CONCLUSION

Prior RS before developing advanced disease was associated with better outcomes in patients with aUC treated with ICIs in the second-plus-line but not in the first-line setting. While further validation is needed, our findings could have implications for prognostic estimates in clinical discussions and benchmarking for clinical trials. Limitations include the study's retrospective nature, lack of randomization, and possible selection and confounding biases.

Update in collecting duct carcinoma: Current aspects of the clinical and molecular characterization of an orphan disease

Collecting duct renal cell carcinoma (cdRCC), which until recently was thought to arise from the collecting ducts of Bellini in the renal medulla, is a rare and aggressive type of non-clear renal cell carcinoma (ncRCC), accounting for 1% of all renal tumors and with nearly 50% of patients being diagnosed with Stage IV disease. The median overall survival in this setting is less than 12 months. Several regimens of chemotherapies had been used based on morphologic and cytogenetic similarities with urothelial cell carcinoma described previously, although the prognosis still remains poor. The use of targeted therapies also did not result in favorable outcomes. Recent works using NGS have highlighted genomic alterations in SETD2, CDKN2A, SMARCB1, and NF2. Moreover, transcriptomic studies have confirmed the differences between urothelial carcinoma and cdRCC, the possible true origin of this disease in the distal convoluted tubule (DCT), differentiating from other RCC (e.g., clear cell and papillary) that derive from the proximal convoluted tubule (PCT), and enrichment in immune cells that may harbor insights in novel treatment strategies with immunotherapy and target agents. In this review, we update the current aspects of the clinical, molecular characterization, and new targeted therapeutic options for Collecting duct carcinoma and highlight the future perspectives of treatment in this setting.

Association Between Sites of Metastasis and Outcomes With Immune Checkpoint Inhibitors in Advanced Urothelial Carcinoma

BACKGROUND

Sites of metastasis have prognostic significance in advanced urothelial carcinoma (aUC), but more information is needed regarding outcomes based on metastatic sites in patients treated with immune checkpoint inhibitors (ICI). We hypothesized that presence of liver/bone metastases would be associated with worse outcomes with ICI.

METHODS

We identified a retrospective cohort of patients with aUC across 26 institutions, collecting demographics, clinicopathological, treatment, and outcomes information. Outcomes were compared with logistic (observed response rate; ORR) and Cox (progression-free survival; PFS, overall survival; OS) regression between patients with/without metastasis beyond lymph nodes (LN) and those with/without bone/liver/lung metastasis. Analysis was stratified by 1st or 2nd+ line.

RESULTS

We identified 917 ICI-treated patients: in the 1st line, bone/liver metastases were associated with shorter PFS (Hazard ratio; HR: 1.65 and 2.54), OS (HR: 1.60 and 2.35, respectively) and lower ORR (OR: 0.48 and 0.31). In the 2nd+ line, bone/liver metastases were associated with shorter PFS (HR: 1.71 and 1.62), OS (HR: 1.76 and 1.56) and, for bone-only metastases, lower ORR (OR: 0.29). In the 1st line, LN-confined metastasis was associated with longer PFS (HR: 0.53), OS (HR:0.49) and higher ORR (OR: 2.97). In the 2nd+ line, LN-confined metastasis was associated with longer PFS (HR: 0.47), OS (HR: 0.54), and higher ORR (OR: 2.79); all associations were significant.

CONCLUSION

Bone and/or liver metastases were associated with worse, while LN-confined metastases were associated with better outcomes in patients with aUC receiving ICI. These findings in a large population treated outside clinical trials corroborate data from trial subset analyses.

Radium-223 for patients with metastatic castration-resistant prostate cancer with asymptomatic bone metastases progressing on first-line abiraterone acetate or enzalutamide: A single-arm phase II trial

PURPOSE

The paper aims to evaluate the efficacy and safety of ²²³Ra in patients who progressed after first-line androgen deprivation therapy.

PATIENTS AND METHODS

EXCAAPE (NCT03002220) was a multicentre, single-arm, open-label, non-controlled phase IIa trial in 52 patients with metastatic castration-resistant prostate cancer and asymptomatic bone metastases who have progressed on abiraterone acetate or enzalutamide, up to six doses of ²²³Ra (55 kBq/kg of body weight per month). The primary end-point was radiographic progression-free survival (rPFS). Secondary end-points included rPFS based on androgen receptor splice variant 7 (AR-V7) expression in circulating tumour cells (CTCs), overall survival, and safety.

RESULTS

Median rPFS was 5.5 months (95% CI 5.3-5.5). Median rPFS of patients with AR-V7(-) CTCs was longer than that of patients with AR-V7(+) CTCs (5.5 versus 2.2 months, respectively; P = 0.056). Median overall survival was 14.8 months (95% CI 11.2-not reached) and was significantly greater for AR-V7(-) patients than for AR-V7(+) patients (14.8 months versus 3.5 months, respectively; P < 0.01). ²²³Ra was well tolerated; anaemia and thrombocytopenia were the most common grade 3/4 adverse events (5.8% and 11.5%, respectively).

CONCLUSIONS

²²³Ra seems to be a reasonable treatment for patients with metastatic castration-resistant prostate cancer and asymptomatic bone metastases progressing on novel hormonal therapy and had an acceptable safety profile.

Health-related quality of life (HRQoL) for patients with advanced/metastatic urothelial carcinoma (UC) enrolled in KEYNOTE-052 who are potentially platinum ineligible

4561

Background: Frontline cisplatin-based chemotherapy improves survival in patients (pts) with UC, but ̃50% are cisplatin-ineligible owing to poor performance status or comorbidity. The definition of platinum ineligibility is not standardized; hence, treatment decisions are almost solely made by clinical judgment. Pembrolizumab (pembro) showed antitumor activity and manageable toxicity as frontline therapy in 370 cisplatin-ineligible pts in the single arm, phase 2 KEYNOTE-052 trial (NCT02335424). We present effects of pembro on HRQoL of pts in KEYNOTE-052 who were potentially platinum ineligible in this exploratory analysis. Methods: Eligible pts for KEYNOTE-052 were adults with no prior systemic chemotherapy for advanced/metastatic UC, ECOG PS ≤2, and measurable disease per RECIST v1.1 by blinded independent central review. Pembro 200 mg IV was administered Q3W for up to 2 y. Clinical characteristics of frail pts (platinum ineligible) were identified by extensive review of real-world treatment patterns and relevant literature. Consequently, platinum ineligibility was defined as having an ECOG PS ≥2 plus ≥1 of the following: visceral disease, creatinine clearance < 60 mL/min, or age ≥80 y. HRQoL was assessed using the EORTC QLQ-C30 and EQ-5D-3L during the first 4 cycles, then every 2 cycles for 1 year or until treatment discontinuation (whichever occurred first), and at least 30 days after treatment discontinuation. Key end points were change from baseline per the QLQ-C30 global health status (GHS)/QoL score, QLQ-C30 physical functioning subscale, and EQ-5D visual analog scale (VAS). The minimum important difference (MID) was 10 for QLQ-C30 score change (improved: ≥10; stable: –10 to 10; deteriorated: –10 or less); MID for VAS score change was 7 (improved: ≥7; stable: –7 to 7; deteriorated: –7 or less). Results: Median age for 143 pts was 75 y (range, 34-91); 129 pts (90.2%) had visceral disease; 142 (99.3%) had ECOG PS 2; 1 had ECOG PS 3 (enrolled in error). Compliance rate for HRQoL questionnaires was 93.7% at baseline. At the prespecified analysis time of week 9, 77.6% of pts had improved (n = 51) or stable (n = 60) QLQ-C30 GHS/QoL scores, 64.3% had improved (n = 35) or stable (n = 57) QLQ-C30 physical functioning scores, and 62.2% had improved (n = 56) or stable (n = 33) EQ-5D VAS scores. These scores were stable throughout the HRQoL assessment period for pts who continued pembro. Conclusions: In this exploratory analysis, pembro maintained HRQoL for pts with advanced/metastatic UC in KEYNOTE-052 who were potentially platinum-ineligible per the above criteria. Together with the efficacy and safety data from KEYNOTE-052, these data suggest that pembro monotherapy is a valuable treatment option for select pts with advanced UC who are more senior and/or deemed medically frail. Clinical trial information: NCT02335424.

Response and Outcomes to Immune Checkpoint Inhibitors in Advanced Urothelial Cancer Based on Prior Intravesical Bacillus Calmette-Guerin

BACKGROUND

Immune checkpoint inhibitors (ICI) improve overall survival (OS) in patients with locally advanced, unresectable, or metastatic urothelial carcinoma (aUC), but response rates can be modest. We compared outcomes between patients with and without prior intravesical Bacillus Calmette-Guerin (BCG), who received ICI for aUC, hypothesizing that prior intravesical BCG would be associated with worse outcomes.

PATIENTS AND METHODS

We performed a retrospective cohort study across 25 institutions in US and Europe. We compared observed response rate (ORR) using logistic regression; progression-free survival (PFS) and OS using Kaplan-Meier and Cox proportional hazards. Analyses were stratified by treatment line (first line/salvage) and included multivariable models adjusting for known prognostic factors.

RESULTS

A total of 1026 patients with aUC were identified; 614, 617, and 638 were included in ORR, OS, PFS analyses, respectively. Overall, 150 pts had history of prior intravesical BCG treatment. ORR to ICI was similar between those with and without prior intravesical BCG exposure in both first line and salvage settings (adjusted odds radios 0.55 [P= .08] and 1.65 [P= .12]). OS (adjusted hazard ratios 1.05 [P= .79] and 1.13 [P= .49]) and PFS (adjusted hazard ratios 1.12 [P= .55] and 0.87 [P= .39]) were similar between those with and without intravesical BCG exposure in first line and salvage settings.

CONCLUSION

Prior intravesical BCG was not associated with differences in response and survival in patients with aUC treated with ICI. Limitations include retrospective nature, lack of randomization, presence of selection and confounding biases. This study provides important preliminary data that prior intravesical BCG exposure may not impact ICI efficacy in aUC.

Association of TMB and PD-L1 with efficacy of first-line pembrolizumab (pembro) or pembro + chemotherapy (chemo) versus chemo in patients (pts) with advanced urothelial carcinoma (UC) from KEYNOTE-361

540

Background: The 3-arm, open-label, phase 3 KEYNOTE-361 study (NCT02853305) evaluated first-line pembro ± chemo vs chemo in advanced UC regardless of PD-L1 status. The trial did not meet its primary end points of superior PFS and OS with pembro + chemo vs chemo and thus analysis of pembro monotherapy (mono) vs chemo was exploratory. We explored the association of TMB status and PD-L1 combined positive score (CPS) with clinical outcomes in KEYNOTE-361. Methods: In pts with TMB and/or PD-L1 data, the association between TMB (via whole exome sequencing) and PD-L1 (via PD-L1 IHC 22C3 pharmDx) and clinical outcomes (ORR, PFS, and OS) was evaluated. In each treatment arm, the hypotheses regarding the associations were evaluated using logistic regression (ORR) and Cox proportional hazards regression (PFS; OS), and 1-sided (pembro; pembro + chemo) and 2-sided (chemo) P values were calculated; significance was prespecified at α = 0.05 without multiplicity adjustment. Clinical utility was assessed using prespecified cutoffs of 175 mut/exome (TMB) and CPS 10 (PD-L1). Clinical data cutoff was April 29, 2020. Results: 820/993 pts (82.6%) had evaluable TMB data (pembro, 252; pembro + chemo, 282; chemo, 286). TMB (log10) was significantly positively associated with ORR, PFS, and OS for pembro ( P < 0.001, < 0.001, and 0.007, respectively) and PFS and OS for pembro + chemo ( P= 0.007 and 0.010, respectively). The area under the receiver operating characteristics (AUROC) curve (95% CI) for discriminating response was 0.64 (0.56-0.71) for pembro, 0.53 (0.46-0.60) for pembro + chemo, and 0.52 (0.45-0.59) for chemo. Efficacy by TMB cutoff is reported in the Table. All 993 pts had PD-L1 data (pembro, 302; pembro + chemo, 349; chemo, 342). PD-L1 was significantly positively associated with PFS for pembro ( P= 0.006) and ORR for pembro + chemo ( P= 0.042) but not chemo. Efficacy by PD-L1 CPS is reported in the Table. Conclusions: Strong associations were observed between TMB and all 3 clinical outcomes (ORR, PFS, and OS) with pembro mono in the first-line setting and a reduced association was observed between TMB and clinical outcomes with pembro + chemo. No consistent associations were observed between PD-L1 and clinical outcomes with pembro mono or pembro + chemo. Clinical trial information: NCT02853305. [Table: see text]

Post hoc pooled analysis of first-line (1L) pembrolizumab (pembro) for advanced urothelial carcinoma (UC): Outcomes by response at week nine in KEYNOTE-052 and KEYNOTE-361

519

Background: Pembro is a 1L treatment for cisplatin-ineligible pts with UC. This post hoc landmark analysis evaluated clinical outcomes by response at 9 wk to 1L pembro monotherapy in pts with advanced/unresectable or metastatic UC from the single-arm phase 2 KEYNOTE-052 (NCT02335424) and the randomized phase 3 KEYNOTE-361 (NCT02853305) trials. Methods: Cisplatin-ineligible pts with advanced UC were enrolled in KEYNOTE-052 and received pembro (200 mg Q3W for ≤2 y). Platinum-eligible pts with advanced UC who had not previously received systemic chemotherapy (chemo) were enrolled in KEYNOTE-361 and randomly assigned 1:1:1 to receive pembro (200 mg Q3W for ≤2 y), pembro + chemo (1000 mg/m2 gemcitabine on d1 and d8 + cisplatin [70 mg/m2] or carboplatin [AUC 5] on d1 of each 3-wk cycle), or chemo. The primary analysis group included pembro monotherapy–treated pts; the sensitivity analysis group included pembro monotherapy–treated pts from KEYNOTE-052 and the choice of carboplatin subpopulation of pembro monotherapy–treated pts from KEYNOTE-361. Landmark analyses of OS by pts with CR, PR, SD, or PD per RECIST v1.1 by BICR at first imaging assessment (wk 9) were pooled for the ITT populations. Duration of CR/PR/SD and OS were estimated using the Kaplan-Meier method. Data cutoffs were Sep 26, 2020 (KEYNOTE-052) and Apr 29, 2020 (KEYNOTE-361). Results: The primary analysis group included 681 pembro-treated pts (KEYNOTE-052, N = 374; KEYNOTE-361, N = 307); the sensitivity analysis group included 544 pembro-treated pts (KEYNOTE-052, N = 374; KEYNOTE-361, N = 170). Median time from randomization to cutoff was 51.9 mo (range, 22.0-65.3) and 53.7 mo (range, 22.0-65.3) for the primary and sensitivity analysis groups, respectively. Twenty-five pts (4.6%) had CR and 135 (24.6%) had PR (primary group); 17 pts (3.9%) had CR and 105 (24.1%) had PR (sensitivity group). Median DOR was 25.9 mo for pts with CR/PR at wk 9; pts with CR/PR or SD at wk 9 had longer OS than pts with PD at wk 9 (Table). Conclusions: In this post hoc analysis, pts with advanced UC in KEYNOTE-052 and KEYNOTE-361 with CR/PR at wk 9 had better clinical outcomes with pembro monotherapy than pts with SD or PD; 1L pembro monotherapy continues to show efficacy in advanced UC. Clinical trial information: NCT02335424 and NCT02853305. [Table: see text]

Association of time to second-line (2L) immune-checkpoint inhibitors (ICI) and outcomes with ICIs in patients (pts) with advanced urothelial carcinoma (aUC)

505

Background: Current standard therapy for most pts with aUC is first-line (1L) platinum-based chemotherapy followed by ICI maintenance (or 2L if progression). Shorter time on 1L or between therapy lines may be a surrogate of more aggressive disease and poor outcome, but its prognostic role in ICI response is unclear. We hypothesized that shorter time until start of 2L ICI would be associated with worse outcomes in aUC. Methods: We performed a retrospective multi-institution cohort study in pts with aUC treated with 1L platinum-based chemotherapy, who later received 2L ICI. Pts receiving maintenance ICI were excluded. We calculated the time from start of 1L platinum chemotherapy to start of 2L ICI, dichotomizing the exposure into ≤6 months and >6 months. We compared overall response rate (ORR) to 2L ICI, progression-free survival (PFS) and overall survival (OS) from the start of 2L ICI between the two populations. ORR was compared among groups using multivariable logistic regression and PFS, OS using cox regression. Analysis was adjusted for calculated Bellmunt score. Results: From a total of 1283 pts, 462 received 1L platinum chemotherapy; among those, 350 received 2L ICI. After exclusions, 270, 269 and 260 pts were included in the ORR, PFS and OS analyses, respectively. Median age was 70 years, 78% men, 75% White, 74% with pure urothelial histology, 21% upper tract, 60% received cisplatin in 1L. Pts with time to 2L ICI ≤6 months had significantly higher Bellmunt scores (32% vs 22% score=2, 9% vs 3% score=3). ORR and PFS were comparable between pts with ≤ and >6 months to 2L ICI. However, OS was significantly longer for pts with >6 months to 2L ICI (median [m]OS 13 vs 7 months, p=0.002), (Table). Conclusions: Among pts with aUC treated with 2L ICI, time to 2L ICI ≤6 months from 1L platinum based chemotherapy was associated with similar ORR and PFS but shorter OS. Limitations include retrospective nature, patient selection, confounding factors. More studies are needed on the impact of platinum resistance in pts with aUC treated with ICIs.[Table: see text]

Immune checkpoint inhibitors in advanced upper and lower tract urothelial carcinoma: a comparison of outcomes

OBJECTIVES

To compare clinical outcomes between patients with locally advanced (unresectable) or metastatic urothelial carcinoma (aUC) in the upper and lower urinary tract receiving immune checkpoint inhibitors (ICIs).

PATIENTS AND METHODS

We performed a retrospective cohort study collecting clinicopathological, treatment, and outcome data for patients with aUC receiving ICIs from 2013 to 2020 across 24 institutions. We compared the objective response rate (ORR), overall survival (OS), and progression-free survival (PFS) between patients with upper and lower tract UC (UTUC, LTUC). Uni- and multivariable logistic and Cox regression were used to assess the effect of UTUC on ORR, OS, and PFS. Subgroup analyses were performed stratified based on histology (pure, mixed) and line of treatment (first line, subsequent line).

RESULTS

Out of a total of 746 eligible patients, 707, 717, and 738 were included in the ORR, OS, and PFS analyses, respectively. Our results did not contradict the hypothesis that patients with UTUC and LTUC had similar ORRs (24% vs 28%; adjusted odds ratio [aOR] 0.73, 95% confidence interval [CI] 0.43-1.24), OS (median 9.8 vs 9.6 months; adjusted hazard ratio [aHR] 0.93, 95% CI 0.73-1.19), and PFS (median 4.3 vs 4.1 months; aHR 1.01, 95% CI 0.81-1.27). Patients with mixed-histology UTUC had a significantly lower ORR and shorter PFS vs mixed-histology LTUC (aOR 0.20, 95% CI 0.05-0.91 and aHR 1.66, 95% CI 1.06-2.59), respectively).

CONCLUSION

Overall, patients with UTUC and LTUC receiving ICIs have comparable treatment response and outcomes. Subgroup analyses based on histology showed that those with mixed-histology UTUC had a lower ORR and shorter PFS compared to mixed-histology LTUC. Further studies and evaluation of molecular biomarkers can help refine patient selection for immunotherapy.

PARP inhibitors in advanced prostate cancer: when to use them?

Poly (ADP-ribose) polymerase (PARP) inhibitors have antitumor activity in advanced prostate cancer associated with loss of homologous recombination repair (HRR) function. About 20% of all patients with advanced prostate cancer present germline or tumor mutations in HRR-related genes, the most common being BRCA2, mutated in approximately 10% of all advanced prostate cancers. Challenges related to sample availability, tumor heterogeneity and access to NGS technology need to be addressed for a successful implementation of genomic stratification in routine clinical practice. The recent regulatory approvals of PARP inhibitors olaparib and rucaparib represent the first molecular biomarker-guided drugs for men with prostate cancer. While these findings represent a significant advance in the field of precision medicine and prostate cancer, there are still many unsolved questions on the optimal use of PARP inhibitors in this disease. Several clinical trials have shown that different mutations in various genes are associated with distinct magnitudes of sensitivity to PARP inhibitors, with BRCA2 mutations associating with more frequent and durable responses, questioning the benefit for subset of patients with mutations in other HRR-associated genes. In this review, we scrutinize the clinical development of different PARP inhibitors for the treatment of advanced prostate cancer, and we discuss how the study of additional biomarkers and the design of rational drug combinations can maximize patient benefit from this drug class.

A New Prognostic Model in Patients with Advanced Urothelial Carcinoma Treated with First-line Immune Checkpoint Inhibitors

BACKGROUND

While immune checkpoint inhibitors (ICIs) are approved in the first-line (1L) setting for cisplatin-unfit patients with programmed death-ligand 1 (PD-L1)-high tumors or for platinum (cisplatin/carboplatin)-unfit patients, response rates remain modest and outcomes vary with no clinically useful biomarkers (except for PD-L1).

OBJECTIVE

We aimed to develop a prognostic model for overall survival (OS) in patients receiving 1L ICIs for advanced urothelial cancer (aUC) in a multicenter cohort study.

DESIGN, SETTING, AND PARTICIPANTS

Patients treated with 1L ICIs for aUC across 24 institutions and five countries (in the USA and Europe) outside clinical trials were included in this study.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

We used a stepwise, hypothesis-driven approach using clinician-selected covariates to develop a new risk score for patients receiving ICIs in the 1L setting. Demographics, clinicopathologic data, treatment patterns, and OS were collected uniformly. Univariate Cox regression was performed on 18 covariates hypothesized to be associated with OS based on published data. Variables were retained for multivariate analysis (MVA) if they correlated with OS (p < 0.2) and were included in the final model if p < 0.05 on MVA. Retained covariates were assigned points based on the beta coefficient to create a risk score. Stratified median OS and C-statistic were calculated.

RESULTS AND LIMITATIONS

Among 984 patients, 357 with a mean age of 71 yr were included in the analysis, 27% were female, 68% had pure UC, and 13% had upper tract UC. Eastern Cooperative Oncology Group performance status ≥2, albumin <3.5 g/dl, neutrophil:lymphocyte ratio >5, and liver metastases were significant prognostic factors on MVA and were included in the risk score. C index for new 1L risk score was 0.68 (95% confidence interval 0.65-0.71). Limitations include retrospective nature and lack of external validation.

CONCLUSIONS

We developed a new 1L ICI risk score for OS based on data from patients with aUC treated with ICIs in the USA and Europe outside of clinical trials. The score components highlight readily available factors related to tumor biology and treatment response. External validation is being pursued.

PATIENT SUMMARY

With multiple new treatments under development and approved for advanced urothelial carcinoma, it can be difficult to identify the best treatment sequence for each patient. The risk score may help inform treatment discussions and estimate outcomes in patients treated with first-line immune checkpoint inhibitors, while it can also impact clinical trial design and endpoints. TAKE  HOME MESSAGE: A new risk score was developed for advanced urothelial carcinoma treated with first-line immune checkpoint inhibitors. The score assigned Eastern Cooperative Oncology Group performance status ≥2, albumin <3.5 g/dl, neutrophil:lymphocyte ratio >5, and liver metastases each one point, with a higher score being associated with worse overall survival.

Efficacy and safety of rucaparib in previously treated, locally advanced or metastatic urothelial carcinoma from a phase 2, open-label trial (ATLAS)

BACKGROUND

ATLAS evaluated the efficacy and safety of the PARP inhibitor rucaparib in patients with previously treated locally advanced/unresectable or metastatic urothelial carcinoma (UC).

METHODS

Patients with UC were enrolled independent of tumor homologous recombination deficiency (HRD) status and received rucaparib 600 mg BID. The primary endpoint was investigator-assessed objective response rate (RECIST v1.1) in the intent-to-treat and HRD-positive (loss of genome-wide heterozygosity ≥10%) populations. Key secondary endpoints were progression-free survival (PFS) and safety. Disease control rate (DCR) was defined post-hoc as the proportion of patients with a confirmed complete or partial response (PR), or stable disease lasting ≥16 weeks.

RESULTS

Of 97 enrolled patients, 20 (20.6%) were HRD-positive, 30 (30.9%) HRD-negative, and 47 (48.5%) HRD-indeterminate. Among 95 evaluable patients, there were no confirmed responses. However, reductions in the sum of target lesions were observed, including 6 (6.3%) patients with unconfirmed PR. DCR was 11.6%; median PFS was 1.8 months (95% CI, 1.6-1.9). No relationship was observed between HRD status and efficacy endpoints. Median treatment duration was 1.8 months (range, 0.1-10.1). Most frequent any-grade treatment-emergent adverse events were asthenia/fatigue (57.7%), nausea (42.3%), and anemia (36.1%). Of 64 patients with data from tumor tissue samples, 10 (15.6%) had a deleterious alteration in a DNA damage repair pathway gene, including four with a deleterious BRCA1 or BRCA2 alteration.

CONCLUSIONS

Rucaparib did not show significant activity in unselected patients with advanced UC regardless of HRD status. The safety profile was consistent with that observed in patients with ovarian or prostate cancer.

TRIAL REGISTRATION

This trial was registered in ClinicalTrials.gov (NCT03397394). Date of registration: 12 January 2018. This trial was registered in EudraCT (2017-004166-10).

Safety and efficacy of rogaratinib in combination with atezolizumab in cisplatin-ineligible patients (pts) with locally advanced or metastatic urothelial cancer (UC) and FGFR mRNA overexpression in the phase Ib/II FORT-2 study

4521

Background: Rogaratinib (R) is a novel pan-FGFR inhibitor that showed promising efficacy and safety in a Phase I trial in pts with advanced solid tumors, including UC, with FGFR1-3 mRNA overexpression. The Phase Ib/II FORT-2 study (NCT03473756) of R plus atezolizumab (A) in pts with first-line cisplatin-ineligible, FGFR-positive, advanced/metastatic UC previously identified a maximum tolerated dose of R 600 mg twice daily (BID) plus A (1200 mg every 3 weeks) . We report updated safety, efficacy, and the recommended Phase II dose (RP2D) for combination therapy from the Phase Ib study. Methods: Pts with cisplatin-ineligible, locally advanced/metastatic UC with FGFR1/3 mRNA overexpression detected by RNA in situ hybridization of archival tissue (RNAscope) received oral R 600 mg BID plus A 1200 mg on day 1 of a 21-day cycle. Archival tissue was examined for programmed cell-death ligand 1 (PD-L1) protein expression levels, FGFR3-activating mutations via a targeted Illumina NGS panel, and FGFR fusions via an Archer fusion plex assay. Primary objectives were safety, tolerability, and determination of the RP2D. Results: 26 pts (enrolled May 25, 2018 to Nov 25, 2020) were treated; 89% were male, median age was 76 years (range 47-85), 58% had an ECOG performance status of 1, and 77% displayed low or absent (negative or non-detectable) PD-L1 expression (combined positive score < 10%). Common treatment-emergent adverse events (TEAEs) included diarrhea (n = 17, 65%; 1 grade [G] 3), hyperphosphatemia (n = 15, 58%; all G1 or 2), and nausea (n = 11, 42%; 1 G3). The most common G3/4 TEAEs were elevated lipase without pancreatitis (n = 5, 19%), elevated amylase (n = 3, 12%), and rash and syncope (n = 2, 8% each). TEAEs led to interruption/reduction/discontinuation of R in 69%/46%/19% of pts. R-related unique TEAEs were hyperphosphatemia in 15 pts (58%) and retinal pigment epithelium detachment in 1 pt (4%). G5 events occurred in 3 pts (12%), unrelated to treatment. 13 of 24 evaluable pts (54%) had an objective response (OR) per RECIST v1.1. The disease control rate was 83%, including 3 pts (13%) with a complete response (CR), 10 (42%) with a partial response (PR), and 7 (29%) with stable disease. Median duration of response was not reached. OR rate was 56% (2 CRs and 7 PRs) in the 16 pts with tumors having low/negative PD-L1 protein and FGFR3 mRNA overexpression without mutation. The RP2D for R+A was 600 mg BID. Conclusions: First-line treatment with the RP2D of R+A achieved favorable clinical efficacy and tolerability in pts with cisplatin-ineligible, metastatic UC characterized by high FGFR1/3 mRNA expression and generally low/negative PD-L1 expression. Encouraging efficacy was observed regardless of PD-L1 expression or FGFR3 mutation status, warranting future investigation. Clinical trial information: NCT03473756.

Response and outcomes to immune checkpoint inhibitors (ICI) in advanced urothelial cancer (aUC) based on prior intravesical BCG

4537

Background: Little is known regarding response and outcomes to ICI for patients (pts) with aUC who were previously treated with BCG for non-muscle invasive bladder cancer. We hypothesized that prior intravesical BCG would not be associated with changes in objective response or survival in pts with aUC treated with ICI. Methods: We performed a retrospective cohort study across 25 institutions. Demographic, intravesical BCG history, treatment and outcomes data were collected for pts with aUC who received ICI. Pts with aUC treated with ICIs were included, pts with pure non-UC, those treated with combination or on clinical trials, pts with multiple ICI treatment lines and those with upper tract UC were excluded. Pts were stratified to prior exposure versus no exposure to BCG. We compared overall response rate (ORR) using logistic regression; and progression-free survival (PFS) and overall survival (OS) using Kaplan-Meier and Cox proportional hazards. All analyses were performed in the overall population and further stratified by treatment line (first-line [1L] vs salvage [2+L]) and multivariable models. The stratified analysis was also adjusted for an internally developed risk score for 1L and Bellmunt risk score for 2+L; p<0.05 was significant. Results: 1026 aUC pts treated with ICI were identified; 614 pts, 617 pts, and 641 pts were included in ORR, OS and PFS analyses, respectively. Overall, mean age at CPI initiation was 70, 76% were men, 70% were current or former smokers, 75% White, 29% with mixed histology, and 24% had prior exposure to BCG. ORR to ICI in pts with or without prior exposure to BCG was similar, 27% and 28% respectively (OR=0.93 [95% CI 0.61-1.42], p=0.73). Median OS (mOS) for pts with vs without prior BCG exposure was 9 vs 10 mo (HR=1.13 [95% CI 0.88-1.44], p=0.35). Median PFS (mPFS) was 4 months (mo) in both groups (HR=1.02 [95% CI 0.82-1.27], p=0.83). ORR, PFS and OS analyses stratified by ICI treatment line (1L vs 2+L) are listed in the table. Conclusions: In this multi-institutional retrospective analysis, prior intravesical BCG was not associated with objective response or survival in pts with aUC treated with ICI. Limitations of this study include retrospective nature, lack of randomization and possible confounding, but it does provide important preliminary data that selection for ICI treatment should not be impacted by prior exposure to BCG. Further clinical and molecular biomarker exploration is needed to refine patient selection for ICI in aUC.[Table: see text]

Impact of subsequent therapy on survival in KEYNOTE-361: Pembrolizumab (pembro) plus chemotherapy (chemo) or pembro alone versus chemo as first-line therapy for advanced urothelial carcinoma (UC)

439

Background: The phase III KEYNOTE-361 study examined the efficacy and safety of 1L pembro + chemo or pembro alone vs chemo for pts with advanced UC. The PFS and OS benefit of pembro + chemo vs chemo did not reach statistical significance; no further formal tesing was done. We present an exploratory analysis of OS by subsequent therapy in KEYNOTE-361 (NCT02853305) to assess how 1L and 2L therapy selection affected survival outcomes; no formal comparisons were conducted. Methods: OS was estimated for pts by whether they received subsequent therapy, and by whether subsequent therapy included an anti–PD-(L)1 agent. Results: 351 pts were randomized to pembro + chemo, 307 pts to pembro, and 352 pts to chemo. As of Apr 29, 2020, the median (range) time from randomization to data cutoff was 31.7 (22.0-42.3) mo. 124/351 pts (35%) in the pembro + chemo arm, 126/307 pts (41%) in the pembro arm, and 215/352 pts (61%) in the chemo arm received any subsequent therapy. Similar rates of subsequent therapy (pembro + chemo: 32%; pembro: 43%; chemo: 59%) were observed for pts who experienced progressive disease (PD) by blinded independent central review (BICR). A higher rate of pts (169/352 [48%]) in the chemo arm received subsequent anti–PD-(L)1 therapy than in either the pembro + chemo arm (23/351 [7%]) or pembro arm (14/307 [5%]). Due to the small pt numbers, pts in the pembro + chemo or pembro arms who received subsequent anti−PD-(L)1 were not considered further. This analysis included all pts who received 2L therapy (465/1010 pts [46%]); the rate of 2L therapy was similar in pts with PD by BICR (274/615 [45%]). Chemo agents alone or in combination, specifically carboplatin, cisplatin, docetaxel, doxorubicin, gemcitabine, and paclitaxel, were the most commonly received subsequent therapies for pts who did not receive anti–PD-(L)1 in 2L. Pts who received 1L chemo followed by subsequent anti–PD-(L)1 had longer mOS (19.1 mo [95% CI 16.2-22.2]) than pts with 1L pembro followed by 2L therapy not including an anti−PD-(L)1 agent (16.0 mo [95% CI 11.8-19.2]) (Table). Conclusions: In this exploratory analysis, favorable survival outcomes were observed for pts who received 1L chemo followed by anti–PD-(L)1 compared with pts who received 1L pembro followed by 2L therapy not including an anti–PD-(L)1 agent. These data underline the continued importance of immunotherapy as 2L therapy for advanced UC. Clinical trial information: NCT02853305 . Research Sponsor: Merck & Co., Inc[Table: see text]

Immune checkpoint inhibitors (ICI) in advanced upper tract and lower tract urothelial carcinoma (UC): A comparison of outcomes

406

Background: Despite anatomical and biological differences, upper and lower tract UC (UTUC; LTUC) are usually managed similarly. Modern era clinical trial data comparing their outcomes with ICI are conflicting. We hypothesized that response and outcomes would be similar in patients (pts) with advanced UTUC and LTUC. Methods: We performed a retrospective cohort study collecting demographic, clinicopathologic, treatment, and outcome data for pts with advanced UC receiving ICI (2013-2020) across 24 centers (US; Europe). We compared objective response rate (ORR), overall survival (OS), and progression-free survival (PFS) between pts with UTUC and LTUC. Uni- / multi- variable logistic and Cox regression were used to assess the effect of UTUC on ORR, OS, and PFS. Stratified subgroup analyses were performed according to histology (pure, mixed) and line of treatment (first-line, subsequent). Results: A total of 984 pts were identified, and 707, 717, and 738 were included in ORR, OS, and PFS analyses, respectively. After exclusions, the UTUC group comprised of 130 pts (vs. 616 in LTUC) with median age 71 (40-92) (vs. 70 [32-93]), 62% men (vs. 76%), 41% never smokers (vs. 29%), 62% with history of prior radical surgery for primary tumor (vs. 52%), and 29% with liver metastases (vs. 18%). Table shows results of ORR, OS, and PFS analyses. In the overall population, pts with UTUC and LTUC receiving ICI had comparable ORR, OS, and PFS. Pts with mixed-histology UTUC had significantly lower ORR (adjusted OR 0.20, 95%CI 0.05-0.91) and shorter PFS (adjusted HR 1.66, 95%CI: 1.06-2.59) vs. mixed-histology LTUC. Conclusions: Pts with advanced UTUC and LTUC receiving ICI have similar response and outcomes, except for pts with mixed-histology UTUC vs LTUC. Subset analysis of primary tumor location in ongoing clinical trials can validate our data, while biomarker work is ongoing. [Table: see text]

Analysis of PFS2 by subsequent therapy in KEYNOTE-361: Pembrolizumab (pembro) plus chemotherapy (chemo) or pembro alone versus chemo as 1L therapy for advanced urothelial carcinoma (UC)

448

Background: 1L pembro + chemo did not show statistically superior PFS and OS vs chemo for pts with advanced UC in the phase III KEYNOTE-361 study; OS for pembro vs chemo was not formally tested. We analyzed PFS2 (time from randomization to progressive disease [PD] on first subsequent therapy, or death from any cause, whichever occurs first) by study treatment and subsequent therapy in KEYNOTE-361 (NCT02853305) to determine the effects, if any, of therapy sequence on PFS2. Methods: PFS2 was estimated for pts in each treatment arm, who received any subsequent therapy including any anti–PD-(L)1, any therapy other than anti–PD-(L)1, or no therapy. These were exploratory analyses; no formal comparisons were done. Results: 1010 pts were randomized: 351 pts to receive pembro + chemo, 307 to pembro, and 352 to chemo. As of Apr 29, 2020, the median (range) time from randomization to data cutoff was 31.7 (22.0-42.3) mo. Subsequent therapy was received by 124/351 (35%), 126/307 (41%), and 215/352 (61%) pts in the pembro + chemo, pembro, and chemo arms, respectively. Subsequent anti–PD-(L)1 therapy was received by 169/352 (48%) pts in the chemo arm vs 23/351 (7%) in the pembro + chemo arm and 14/307 (5%) in the pembro arm. Of pts in the pembro arm who received subsequent therapy, >90% received 2L cisplatin-based or carboplatin-based treatment. Median (m) PFS2 (95% CI) for all pts by treatment arm was 14.1 mo (12.6-16.2) with pembro + chemo, 10.9 mo (9.5-12.9) with pembro, and 10.4 mo (9.8-11.2) with chemo. Across treatment arms, pts in the pembro + chemo arm had the longest mPFS2 with any subsequent therapy (14.5 mo [95% CI 13.1-16.6]) (Table). Pts in the pembro arm who received no subsequent therapy had a longer mPFS2 (12.9 mo [95% CI 8.1-17.9]) vs pts in the chemo arm who received no subsequent therapy (9.4 mo [95% CI 7.6-10.6]). Finally, pts treated with 1L pembro in the trial followed by 2L therapy other than anti−PD-(L)1 had comparable mPFS2 (10.2 mo [95% CI 8.6-12.1]) to pts treated with 1L chemo in the trial followed by 2L anti−PD-(L)1 (11.1 mo [95% CI 10.2-12.9]). Conclusions: In this exploratory analysis, treatment sequence of chemo followed by anti−PD-(L)1 upon PD vs anti–PD-(L)1 followed by chemo upon PD did not appear to impact mPFS2. Among pts who did not receive 2L therapy, 1L pembro appeared to be associated with longer mPFS2 than chemo, potentially driven by long-term responders to pembro. Clinical trial information: NCT02853305 . [Table: see text]

Association between prior radical surgery (RS) and outcomes with immune checkpoint inhibitor (ICI) therapy for advanced urothelial carcinoma (aUC)

444

Background: It is unclear whether prior RS of primary tumor is associated with response and outcomes with ICI in aUC. We hypothesized that such response and outcomes would not differ based on prior RS. Methods: We performed a retrospective cohort study including patients (pts) with aUC who received ICI. We compared overall response rate (ORR), progression-free survival (PFS), and overall survival (OS) between pts with vs without RS [cystectomy or (nephro)-ureterectomy]. Analysis was stratified based on ICI therapy line (first-line vs salvage). A separate comparison between pts with prior RS or radiation (RT) only or none was also pursued. ORR was compared between groups using logistic regression, as well OS and PFS using cox regression analysis; a multivariable model was built adjusting for calculated Bellmunt score. P<0.05 was significant. Results: We identified 984 pts from 24 institutions; 682, 704 and 673 were included in OS, PFS and ORR analyses, respectively; 54% of pts had prior RS with median age 68 at ICI initiation with RS vs 71 without RS with similar proportion of men (73-74%) and ever smokers (70-71%). The RS group had higher proportion (%) of white pts (77% vs 71%), lower % of pts with Hb<10g/dL at ICI initiation (23% vs 32%) but not significantly higher % of liver metastasis at ICI initiation (23% vs 17%). Bellmunt score with vs without RS was 16% vs 11%, 50% vs 48%, 27% vs 37%, 7% vs 4% for 0, 1, 2, and 3, respectively. ORR and PFS were not significantly different between groups, while prior RS was associated with longer OS (unadjusted HR 0.8, p=0.03). However, after adjustment for Bellmunt score, this association was not significant (table). Upon stratification based on treatment line, OS was longer with prior RS (0.7, p=0.03) for those treated with salvage ICI but this was not significant after adjusting for Bellmunt score. ORR, PFS and OS were not significantly different between pts receiving prior RT only vs RS vs none. Conclusions: Prior RS was not significantly associated with longer OS in pts with aUC receiving ICI after adjusting for Bellmunt score. Further work is needed to interrogate tumor-host immune interactions and identify biomarkers that can be prognostic and/or predictive of ICI response. [Table: see text]

A phase Ib single-arm study of bintrafusp alfa for the treatment of pretreated, locally advanced/unresectable or metastatic urothelial cancer

TPS501

Background: Urothelial cancer (UC) is the most common histological subtype of bladder cancer. For patients with metastatic UC, platinum-containing chemotherapy (CT) is the first-line standard of care. With 5 PD-(L)1 inhibitors approved for second-line treatment of platinum-refractory advanced UC, objective response rates (ORRs) in this setting (15% to 21%) and in first-line cisplatin-ineligible patients (23% to 31%) suggest that there remains a significant unmet need for improved outcomes. TGF-β signaling has been associated with resistance to PD-(L)1 inhibitors in patients with UC. Bintrafusp alfa (BA) is a first-in-class bifunctional fusion protein composed of the extracellular domain of the TGF-βRII receptor (a TGF-β “trap”) fused to a human IgG1 mAb blocking PD-L1. In murine models, BA resulted in improved antitumor activity vs TGF-β or PD-L1 monotherapies alone or in combination. In 2 phase I trials (NCT02517398 and NCT02699515), BA demonstrated a manageable safety profile and encouraging clinical efficacy in >670 patients with advanced solid tumors. Here we describe a phase Ib study (NCT04349280) that will assess the clinical activity and safety profile of BA in platinum-experienced patients with locally advanced/unresectable or metastatic UC. Colocalized, simultaneous inhibition of the TGF-β and PD-L1 pathways by BA is hypothesized to elicit greater antitumor activity than anti–PD-(L)1 therapies in patients with UC. Methods: This open-label, multicenter, single-arm trial is accruing patients with histologically confirmed locally advanced/unresectable or metastatic UC (ECOG PS ≤1) with disease progression or recurrence after platinum-based CT. Patients must not have received >2 lines of systemic therapy for metastatic disease or prior therapy targeting T-cell costimulation, or checkpoint or TGF-β pathways. Patients with pneumonitis or a history of noninfectious pneumonitis that required systemic immunosuppression are ineligible. Patients will receive BA 1200 mg every 2 weeks until progression, unacceptable toxicity, death, or study withdrawal, or for up to 2 years. The primary endpoint is investigator-assessed confirmed ORR per RECIST 1.1; key secondary endpoints include duration of response and progression-free survival per the investigator and IRC, overall survival, safety, immunogenicity, and pharmacokinetics. Exploratory biomarker analyses will be conducted using patient samples collected during screening and prior to administration of BA. The base ORR used for the null hypothesis is 21%, and the target ORR is 40%. Using a predictive probability design and an estimated enrollment of 40 patients, the type I error rate is 5.70% and the power is 85.39%. As of September 2020, 3 sites in 2 countries have been activated and no patients have been enrolled. Clinical trial information: NCT04349280.

1L pembrolizumab (pembro) versus chemotherapy (chemo) for choice-of-carboplatin patients with advanced urothelial carcinoma (UC) in KEYNOTE-361

450

Background: 1L pembro is approved in advanced UC for cisplatin-ineligible pts with PD-L1 combined positive score (CPS) ≥10 and any platinum-ineligible pts regardless of CPS in the United States based on single-arm trial data. In the phase III KEYNOTE-361 study, 1L pembro + chemo did not statistically significantly improve PFS or OS vs chemo for pts with advanced UC; formal testing of 1L pembro vs chemo was not performed. We present an exploratory analysis of outcomes with pembro vs chemo for choice-of-carboplatin (carbo) pts in KEYNOTE-361 (NCT02853305). Methods: At randomization, choice of platinum agent (cisplatin or carbo) plus gemcitabine for each pt was selected based on investigator’s assessment of cisplatin ineligibility. ORR/DOR per RECIST v1.1 by blinded independent central review and OS were determined for all pts selected for carbo (“choice-of-carbo”) and also choice-of-carbo pts with CPS ≥10. Risk difference assessment for select AEs for pembro vs chemo was conducted in choice-of-carbo pts who received ≥1 dose study treatment. Results: As of Apr 29, 2020, the median (range) time from randomization to data cutoff in the full study cohort was 31.7 (22.0-42.3) mo. At randomization, renal impairment was the most common reason for choice of carbo by investigators (36% of all pts). 170 choice-of-carbo pts were randomized to the pembro arm, and 196 choice-of-carbo pts to the chemo arm. Median OS in this subgroup was 14.6 mo with pembro vs 12.3 mo with chemo (HR 0.83 [95% CI 0.65-1.06]). 18-mo OS rate was 42% with pembro vs 40% with chemo. ORR to pembro vs chemo was 27.6% vs 41.8%. Median (range) DOR with pembro vs chemo was not reached (NR) (3.2+-36.1+ mo) vs 6.3 (1.8+-33.8+) mo. 84/170 (49%) and 89/196 (45%) choice-of-carbo pts in the pembro and chemo arms, respectively, had CPS ≥10. In this subgroup, median OS was 15.6 mo with pembro vs 13.5 mo with chemo (HR 0.82 [95% CI 0.57-1.17]). 18-mo OS rate was 44% with pembro vs 43% with chemo. ORR to pembro vs chemo was 29.8% vs 46.1%. Median (range) DOR with pembro vs chemo was NR (4.2-36.1+ mo) vs 8.3 (2.1+-33.8+) mo. Among treated pts (N=166 for pembro, N=190 for chemo), 112 pts (68%) in the pembro arm and 163 pts (86%) in the chemo arm had grade 3-5 AEs of any cause. Pembro was associated with a higher risk of pruritus, while chemo was associated with a higher risk of decreased white blood cell, neutrophil, and platelet counts, nausea, thrombocytopenia, neutropenia, and anemia. Conclusions: Due to the trial design, this subset was not statistically tested and is exploratory. Median OS and 18-mo OS rates did not appear markedly different in the two arms; some parameters such as DOR favored pembro, although longer follow-up is needed to determine median DOR for pembro. The PD-L1 CPS ≥10 did not clearly enrich for responders to pembro in choice-of-carbo pts. Pembro was associated with a lower rate of grade 3-5 AEs of any cause than chemo. Clinical trial information: NCT02853305.

Association between sites of metastases (mets) and outcomes with immune checkpoint inhibitor (ICI) therapy for advanced urothelial carcinoma (aUC)

445

Background: Different metastatic sites have variable prognostic implications in aUC. However, details on response and outcomes with ICI for particular mets is still unknown. We hypothesized that bone and liver mets would have poor response and outcomes with ICIs. Methods: We performed a retrospective cohort study in patients (pts) with aUC who received ICI. We compared overall response rate (ORR) and overall survival (OS) between pts with different mets at ICI initiation. We developed 4 different models: 1) lymph node (LN) only vs other; 2) visceral mets (bone, lung, liver) vs other; 3) bone + liver mets vs bone without liver vs liver without bone vs neither and 4) 6 factor model: a. LN +/- soft tissue/locoregional recurrence b. lung +/- (a) c. bone +/- (b) d. liver +/- (c) e. central nervous system (CNS) +/- (d) and f. other. ORR and OS were compared among groups using multivariable (adjusting for ECOG PS and hemoglobin<10g/dl) logistic regression and cox regression, respectively. Results: We identified 984 pts (24 institutions); 703 and 696 were included in OS and ORR analyses, respectively. Median age at ICI start was 71 (range 32-93), 77% white race, 74% men, 67% ever smokers, 72% pure UC, 18% upper tract UC, 55% extirpative surgery. Prevalence of LN, lung, bone and liver mets at ICI start was 74%, 32%, 27% and 21%, respectively. LN-only mets had significantly higher ORR (44% vs 22%, OR 2.6, p<0.05) and longer mOS (22 vs 8 months, HR 0.5, p<0.05) vs other mets. Visceral mets had significantly lower ORR (21% vs 35%, OR 0.5, p<0.05) and shorter mOS (7 vs 17 months, HR 1.8, p<0.05) vs non-visceral mets. Pts with bone and liver mets had significantly lower ORR and shorter OS vs those with bone or liver mets, which both had significantly lower ORR and shorter OS vs those with neither and with LN +/- local recurrence (Table). Conclusions: In the context of ICI treatment, bone, liver, lung or CNS mets were associated with lower ORR and/or shorter OS, and bone and liver mets were particularly associated with low ORR and short OS. LN-only mets were associated with higher ORR and longer OS. Further work is needed to interrogate site-specific tumor-host immune interactions and identify biomarkers. Research Sponsor: None[Table: see text]

Post-hoc analysis of long-term outcomes in patients with CR, PR, or SD to pembrolizumab (pembro) or platinum-based chemotherapy (chemo) as 1L therapy for advanced urothelial carcinoma (UC) in KEYNOTE-361

435

Background: The phase III KEYNOTE-361 study compared efficacy and safety of 1L pembro + chemo or pembro vs chemo in pts with advanced UC. The trial did not meet its primary endpoints of PFS or OS superiority for pembro + chemo vs chemo; formal testing for OS for pembro vs chemo was not performed. We present a post hoc landmark analysis to examine the durability of CR/PR/SD and long-term survival in pts with CR, PR, or SD to pembro vs chemo at week 9 in KEYNOTE-361 (NCT02853305). Methods: Landmark analyses of OS by CR/PR/SD at 9 weeks after randomization in the ITT population were performed. Pts were included if they had a best response of CR/PR/SD per RECIST v1.1 by blinded independent central review at the landmark date of week 9 (first imaging assessment per study protocol). Duration of CR/PR/SD and OS were estimated by the Kaplan-Meier method. No formal comparisons were performed. Results: 307 pts were randomized to receive pembro and 352 pts to receive chemo in the KEYNOTE-361 study. As of Apr 29, 2020, the median (range) time from randomization to data cutoff was 32.5 (22.0-42.4) mo for the pembo arm and 31.4 (22.1-41.6) mo for the chemo arm. In the landmark analysis, fewer pts had CR/PR/SD at week 9 with pembro (n=137 [45%]) than with chemo (n=253 [72%]). Median (range) duration of response for pembro vs chemo was 18.7 (4.4+-35.4+) vs 12.3 (0.0+-29.7+) mo for pts with CR, and 35.0 (1.1-36.1+) vs 6.1 (0.0+-36.3+) mo for pts with PR. Median (range) duration of SD was 4.8 mo (0.0-38.2+) with pembro and 4.6 mo (0.0-16.1+) with chemo. Median OS (95% CI) for pembro vs chemo was not reached (NR) (25.5-NR) vs NR (19.1-NR) for pts with CR; NR (NR-NR) vs 14.8 mo (12.1-21.0) for pts with PR; and 18.5 mo (13.8-28.8) vs 11.1 mo (8.1-14.6) for pts with SD, respectively. Long-term OS rates were higher with pembro vs chemo across all groups (CR/PR/SD) at week 9 (Table). Conclusions: In this post hoc landmark analysis, chemo was associated with more initial responses than pembro, whereas pembro was associated with longer median duration of CR and PR, and generally longer median OS than chemo. Among pts who achieved CR/PR/SD at week 9, the relative OS benefit for pembro vs chemo increased over time. Clinical trial information: NCT02853305. [Table: see text]

Advanced Prostate Cancer with ATM Loss: PARP and ATR Inhibitors

BACKGROUND

Deleterious ATM alterations are found in metastatic prostate cancer (PC); PARP inhibition has antitumour activity against this subset, but only some ATM loss PCs respond.

OBJECTIVE

To characterise ATM-deficient lethal PC and to study synthetic lethal therapeutic strategies for this subset.

DESIGN, SETTING, AND PARTICIPANTS

We studied advanced PC biopsies using validated immunohistochemical (IHC) and next-generation sequencing (NGS) assays. In vitro cell line models modified using CRISPR-Cas9 to impair ATM function were generated and used in drug-sensitivity and functional assays, with validation in a patient-derived model.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

ATM expression by IHC was correlated with clinical outcome using Kaplan-Meier curves and log-rank test; sensitivity to different drug combinations was assessed in the preclinical models.

RESULTS AND LIMITATIONS

Overall, we detected ATM IHC loss in 68/631 (11%) PC patients in at least one biopsy, with synchronous and metachronous intrapatient heterogeneity; 46/71 (65%) biopsies with ATM loss had ATM mutations or deletions by NGS. ATM IHC loss was not associated with worse outcome from advanced disease, but ATM loss was associated with increased genomic instability (NtAI:number of subchromosomal regions with allelic imbalance extending to the telomere, p = 0.005; large-scale transitions, p = 0.05). In vitro, ATM loss PC models were sensitive to ATR inhibition, but had variable sensitivity to PARP inhibition; superior antitumour activity was seen with combined PARP and ATR inhibition in these models.

CONCLUSIONS

ATM loss in PC is not always detected by targeted NGS, associates with genomic instability, and is most sensitive to combined ATR and PARP inhibition.

PATIENT SUMMARY

Of aggressive prostate cancers, 10% lose the DNA repair gene ATM; this loss may identify a distinct prostate cancer subtype that is most sensitive to the combination of oral drugs targeting PARP and ATR.

A CT-based Radiomics Signature Is Associated with Response to Immune Checkpoint Inhibitors in Advanced Solid Tumors

Background Reliable predictive imaging markers of response to immune checkpoint inhibitors are needed. Purpose To develop and validate a pretreatment CT-based radiomics signature to predict response to immune checkpoint inhibitors in advanced solid tumors. Materials and Methods In this retrospective study, a radiomics signature was developed in patients with advanced solid tumors (including breast, cervix, gastrointestinal) treated with anti-programmed cell death-1 or programmed cell death ligand-1 monotherapy from August 2012 to May 2018 (cohort 1). This was tested in patients with bladder and lung cancer (cohorts 2 and 3). Radiomics variables were extracted from all metastases delineated at pretreatment CT and selected by using an elastic-net model. A regression model combined radiomics and clinical variables with response as the end point. Biologic validation of the radiomics score with RNA profiling of cytotoxic cells (cohort 4) was assessed with Mann-Whitney analysis. Results The radiomics signature was developed in 85 patients (cohort 1: mean age, 58 years ± 13 [standard deviation]; 43 men) and tested on 46 patients (cohort 2: mean age, 70 years ± 12; 37 men) and 47 patients (cohort 3: mean age, 64 years ± 11; 40 men). Biologic validation was performed in a further cohort of 20 patients (cohort 4: mean age, 60 years ± 13; 14 men). The radiomics signature was associated with clinical response to immune checkpoint inhibitors (area under the curve [AUC], 0.70; 95% CI: 0.64, 0.77; P < .001). In cohorts 2 and 3, the AUC was 0.67 (95% CI: 0.58, 0.76) and 0.67 (95% CI: 0.56, 0.77; P < .001), respectively. A radiomics-clinical signature (including baseline albumin level and lymphocyte count) improved on radiomics-only performance (AUC, 0.74 [95% CI: 0.63, 0.84; P < .001]; Akaike information criterion, 107.00 and 109.90, respectively). Conclusion A pretreatment CT-based radiomics signature is associated with response to immune checkpoint inhibitors, likely reflecting the tumor immunophenotype. © RSNA, 2021 Online supplemental material is available for this article. See also the editorial by Summers in this issue.

Activity of Platinum-Based Chemotherapy in Patients With Advanced Prostate Cancer With and Without DNA Repair Gene Aberrations

IMPORTANCE

DNA repair gene aberrations occur in 20% to 30% of patients with castration-resistant prostate cancer (CRPC), and some of these aberrations have been associated with sensitivity to poly(ADP-ribose) polymerase (PARP) inhibition platinum-based treatments. However, previous trials assessing platinum-based treatments in patients with CRPC have mostly included a biomarker-unselected population; therefore, efficacy in these patients is unknown.

OBJECTIVE

To characterize the antitumor activity of platinum-based therapies in men with CRPC with or without DNA repair gene alterations.

DESIGN, SETTING, AND PARTICIPANTS

In this case series, data from 508 patients with CRPC treated with platinum-based therapy were collected from 25 academic centers from 12 countries worldwide. Patients were grouped by status of DNA repair gene aberrations (ie, cohort 1, present; cohort 2, not detected; and cohort 3, not tested). Data were collected from January 1986 to December 2018. Data analysis was performed in 2019, with data closure in April 2019.

EXPOSURE

Treatment with platinum-based compounds either as monotherapy or combination therapy.

MAIN OUTCOMES AND MEASURES

The primary end points were as follows: (1) antitumor activity of platinum-based therapy, defined as a decrease in prostate-specific antigen (PSA) level of at least 50% and/or radiological soft tissue response in patients with measurable disease and (2) the association of response with the presence or absence of DNA repair gene aberrations.

RESULTS

A total of 508 men with a median (range) age of 61 (27-88) years were included in this analysis. DNA repair gene aberrations were present in 80 patients (14.7%; cohort 1), absent in 98 (19.3%; cohort 2), and not tested in 330 (65.0%; cohort 3). Of 408 patients who received platinum-based combination therapy, 338 patients (82.8%) received docetaxel, paclitaxel, or etoposide, and 70 (17.2%) received platinum-based combination treatment with another partner. A PSA level decrease of at least 50% was seen in 33 patients (47.1%) in cohort 1 and 26 (36.1%) in cohort 2 (P = .20). In evaluable patients, soft tissue responses were documented in 28 of 58 patients (48.3%) in cohort 1 and 21 of 67 (31.3%) in cohort 2 (P = .07). In the subgroup of 44 patients with BRCA2 gene alterations, PSA level decreases of at least 50% were documented in 23 patients (63.9%) and soft tissue responses in 17 of 34 patients (50.0%) with evaluable disease. In cohort 3, PSA level decreases of at least 50% and soft tissue responses were documented in 81 of 284 patients (28.5%) and 38 of 185 patients (20.5%) with evaluable disease, respectively.

CONCLUSIONS AND RELEVANCE

In this study, platinum-based treatment was associated with relevant antitumor activity in a biomarker-positive population of patients with advanced prostate cancer with DNA repair gene aberrations. The findings of this study suggest that platinum-based treatment may be considered an option for these patients.

Atezolizumab in locally advanced or metastatic urothelial cancer: a pooled analysis from the Spanish patients of the IMvigor 210 cohort 2 and 211 studies

Background

The studies IMvigor 210 cohort 2 and IMvigor211 evaluated the efficacy of atezolizumab in patients with locally advanced or metastatic urothelial cancer (mUC) upon progression to platinum-based chemotherapy worldwide. Yet, the real impact of this drug in specific geographical regions is unknown.

Materials and methods

We combined individual-level data from the 131 patients recruited in Spain from IMvigor210 cohort 2 and IMvigor211 in a pooled analysis. Efficacy and safety outcomes were assessed in the overall study population and according to PD-L1 expression on tumour-infiltrating immune cells.

Results

Full data were available for 127 patients; 74 (58%) received atezolizumab and 53 (42%) chemotherapy. Atezolizumab patients had a numerically superior median overall survival although not reaching statistical significance (9.2 months vs 7.7 months). No statistically significant differences between arms were observed in overall response rates (20.3% vs 37.0%) or progression-free survival (2.1 months vs 5.3 months). Nonetheless, median duration of response was superior for the immunotherapy arm (non-reached vs 6.4 months; p = 0.005). Additionally, among the responders, the 12-month survival rates seemed to favour atezolizumab (66.7% vs 19.9%). When efficacy was analyzed based on PD-L1 expression status, no significant differences were found. Treatment-related adverse events of any grade occurred more frequently in the chemotherapy arm [46/57 (81%) vs 44/74 (59%)].

Conclusion

Patients who achieved an objective response on atezolizumab presented a longer median duration of response and numerically superior 12 month survival rates when compared with chemotherapy responders along with a more favorable safety profile. PD-L1 expression did not discriminate patients who might benefit from atezolizumab.

Safety and preliminary efficacy of rogaratinib in combination with atezolizumab in a phase Ib/II study (FORT-2) of first-line treatment in cisplatin-ineligible patients (pts) with locally advanced or metastatic urothelial cancer (UC) and FGFR mRNA overexpression

5014

Background: Programmed cell-death ligand 1 (PD-L1) overexpression is a mechanism for immune escape in UC. Rogaratinib, an oral pan-FGFR1-4 inhibitor, showed promising efficacy in a Phase I study in pts with solid tumors, including UC, with FGFR1-3 mRNA overexpression (Schuler et al. Lancet Oncol 2019). This Phase Ib/II study is evaluating rogaratinib in combination with atezolizumab, a PD-L1 inhibitor, in pts with FGFR-positive, locally advanced or metastatic UC (NCT03473756). We report results from the Phase Ib study. Methods: Cisplatin-ineligible pts with untreated metastatic UC were eligible if high FGFR1 or 3 mRNA was detected by RNA in situ hybridization of archival tissue (RNAscope). Pts were treated at a starting dose of rogaratinib 800 mg p.o. BID and atezolizumab 1200 mg i.v. on day 1 (21-day cycle). Primary objectives were safety, tolerability, and determination of the recommended Phase II dose. Results: 27 pts were treated (rogaratinib 800 mg + atezolizumab, n = 11; rogaratinib 600 mg + atezolizumab, n = 16); 85% were male, median age was 72 years (range 47-83), 37% had an ECOG PS of 1, and 96% had negative/low PD-L1 expression. Most common treatment-emergent adverse events (TEAEs) were diarrhea (63%), hyperphosphatemia (44%), and urinary tract infection (37%). Dose interruption/reduction due to AEs occurred in 67%/37% of pts; TEAEs lead to discontinuation in 45.5% (800 mg) and 12.5% (600 mg). Most common grade 3/4 TEAEs were increased lipase without pancreatitis (11%), rash, and increased alanine aminotransferase (7% each). Rogaratinib-related unique TEAEs were hyperphosphatemia (44%) and retinal pigment epithelium detachment (4%). The maximum tolerated dose (MTD) was rogaratinib 600 mg BID based on lower overall frequency of AEs. Of 23 evaluable pts (600 mg, n = 13; 800 mg, n = 10), overall 9 (39%) pts had an objective response (RECIST v1.1); 3 (13%) pts had a complete response (600 mg: 2/13 pts), 6 (26%) pts had a partial response (600 mg: 5/13 pts), and 6 (26%) pts had stable disease (600 mg: 4/13 pts). Conclusions: Rogaratinib with atezolizumab showed promising efficacy and safety in cisplatin-ineligible pts with tumor FGFR1 or 3 mRNA-positive UC, with nearly all pts demonstrating low or negative PD-L1 expression. Pts are being enrolled at the MTD of rogaratinib 600 mg BID plus atezolizumab. Clinical trial information: NCT03473756 .

Impact of performance status on treatment outcomes: A real-world study of advanced urothelial cancer treated with immune checkpoint inhibitors

BACKGROUND

Immune checkpoint inhibitors (ICIs) represent an appealing treatment for patients with advanced urothelial cancer (aUC) and a poor performance status (PS). However, the benefit of ICIs for patients with a poor PS remains unknown. It was hypothesized that a poor Eastern Cooperative Oncology Group (ECOG) PS (≥2 vs 0-1) would correlate with shorter overall survival (OS) in patients receiving ICIs.

METHODS

In this retrospective cohort study, clinicopathologic, treatment, and outcome data were collected for patients with aUC who were treated with ICIs at 18 institutions (2013-2019). The overall response rate (ORR) and OS were compared for patients with an ECOG PS of 0 to 1 and patients with an ECOG PS ≥ 2 at ICI initiation. The association between a new ICI in the last 30 and 90 days of life (DOL) and death location was also tested.

RESULTS

Of the 519 patients treated with ICIs, 395 and 384 were included in OS and ORR analyses, respectively, with 26% and 24% having a PS ≥ 2. OS was higher in those with a PS of 0 to 1 than those with a PS ≥ 2 who were treated in the first line (median, 15.2 vs 7.2 months; hazard ratio [HR], 0.62; P = .01) but not in subsequent lines (median, 9.8 vs 8.2 months; HR, 0.78; P = .27). ORRs were similar for patients with a PS of 0 to 1 and patients with a PS ≥ 2 in both lines. Of the 288 patients who died, 10% and 32% started ICIs in the last 30 and 90 DOL, respectively. ICI initiation in the last 30 DOL was associated with increased odds of death in a hospital (odds ratio, 2.89; P = .04).

CONCLUSIONS

Despite comparable ORRs, ICIs may not overcome the negative prognostic role of a poor PS, particularly in the first-line setting, and the initiation of ICIs in the last 30 DOL was associated with hospital death location.

The future of bladder cancer therapy: Optimizing the inhibition of the fibroblast growth factor receptor

Therapeutic options for metastatic bladder cancer (BC) have seen minimal evolution over the past 30 years, with platinum-based chemotherapy remaining the mainstay of standard of care for metastatic BC. Recently, five immune checkpoint inhibitors (ICIs) have been approved by the FDA as second-line therapy, and two ICIs are approved as first-line treatment in selected patients. Molecular alterations of muscle-invasive bladder cancer (MIBC) have been reported by The Cancer Genome Atlas. About 15% of patients with MIBC have molecular alterations in the fibroblast growth factor (FGF) axis. Several ongoing trials are testing novel FGF receptor (FGFR) inhibitors in patients with FGFR genomic aberrations. Recently, erdafitinib, a pan-FGFR inhibitor, was approved by the FDA in patients with metastatic BC who have progressed on platinum-based chemotherapy. We reviewed the literature over the last decade and provide a summary of current knowledge of FGF signaling, and the prognosis associated with FGFR mutations in BC. We cover the role of FGFR inhibition with non-selective and selective tyrosine kinase inhibitors as well as novel agents in metastatic BC. Efficacy and safety data including insights from mechanism-based toxicity are reported for selected populations of metastatic BC with FGFR aberrations. Current strategies to managing resistance to anti-FGFR agents is addressed, and the importance of developing reliable biomarkers as the therapeutic landscape moves towards an individualized therapeutic approach.

Real-world prognostic model for overall survival (OS) in patients (pts) with advanced urothelial cancer (aUC) treated with immune checkpoint inhibitors (ICI)

447

Background: While ICI prolong OS after platinum chemotherapy in aUC, outcomes vary based on clinical confounders. We aimed to develop a prognostic model in pts receiving ICI in a non-clinical trial setting. Methods: We used a hypothesis driven approach of clinician selected covariates to develop a new prognostic model. Data source was a retrospective cohort of pts treated with ICI at 19 institutions. Demographics, clinicopathologic data, treatment patterns, and OS were collected. Univariate (UVA) Cox regression was done on 24 variables hypothesized to be associated with OS. Variables were retained for multivariate analysis (MVA) if they had statistical relationship with OS (p<0.2) and were included in the final model if p<0.05 on MVA. Each retained covariate was assigned 1 point in the final prognostic model. Stratified median OS and c-statistic were calculated. Results: 415 pts with mean age 69, 26% female, 66% ever smokers, 69% pure UC, 15% upper tract UC, 54% with prior extirpative surgery, Bellmunt risk factors 17%, 51%, 28% and 4% for 0, 1, 2, 3, respectively were included. Non-White race, ECOG PS≥1, albumin<3.5g/dL (lower limit of normal), hemoglobin<10g/dL, absolute neutrophil count (ANC)>8x106/ul (upper limit of normal), and presence of bone or liver metastases (mets) were all associated with worse OS on UVA Cox regression; albumin<3.5 g/dL, ANC>8x106/uL, presence of bone or liver mets remained significant on MVA and were included in the prognostic model. Median (m)OS by new model and Bellmunt are shown in table. C-statistic of the new model was 0.67. Conclusions: Albumin<3.5 g/dL, ANC >8x106/ul, presence of bone or liver mets were negative prognostic factors in pts with aUC treated with ICI. This has comparable features to recently reported 5-factor model using clinical trial data, including LDH (unavailable in our cohort). External validation is being pursued. The proposed model may be used for prognostication, clinical trial design, eligibility and stratification. [Table: see text]

Rucaparib for recurrent, locally advanced, or metastatic urothelial carcinoma (mUC): Results from ATLAS, a phase II open-label trial

440

Background: ATLAS (NCT03397394) evaluated the efficacy/safety of the PARP inhibitor (PARPi) rucaparib in patients (pts) with previously treated locally advanced/unresectable UC or mUC. Methods: Pts with measurable disease who had progressed after 1–2 prior regimens (ie, platinum-based chemotherapy [PBC] and/or immune checkpoint inhibitors [ICI]) were enrolled regardless of tumor homologous recombination deficiency (HRD) status. Prior PARPi was not allowed. Pts received rucaparib 600 mg PO BID. Baseline tumor tissue or archival tissue ≤6 mo without intervening therapy was required; serial circulating tumor DNA samples were collected. Primary endpoint was investigator-assessed objective response rate (RECIST v1.1) in the intent-to-treat and HRD-positive (defined as genomic loss of heterozygosity ≥10%) populations. Key secondary endpoints: progression-free survival (PFS) and safety. Clinical benefit rate (CBR) was defined as complete or partial response or stable disease (SD) lasting ≥16 weeks. Results: As of Oct 7, 2019, 97 pts were enrolled (median age 66 y [range, 39–87]); most were men (n=76, 78.4%) and had ECOG PS 1 (n=65, 67.0%). Sixty-six pts (68.0%) had both prior PBC and ICI. Twenty pts (20.6%) were HRD-positive, 30 (30.9%) were HRD-negative and 47 (48.5%) had unknown HRD status; 4 pts had a deleterious BRCA1/2 alteration. Median time on treatment was 54 d (range, 2–224). There were no confirmed responses. Of 96 evaluable pts, 27 (28.1%) had a best response of SD; CBR was 12.5% and median PFS was 1.8 mo. No relationship was observed between HRD status and clinical activity. Treatment was discontinued by 93 pts (95.9%), mainly due to radiologic or clinical progression (73.1%). Most frequent any grade treatment-emergent (any cause) adverse events were asthenia/fatigue (n=56, 57.7%), nausea (n=40, 41.2%), and anemia (n=34, 35.1%). Conclusions: Single agent rucaparib did not show activity in pts with previously treated advanced UC and enrollment was suspended at the first interim analysis. The safety profile was consistent with that observed in pts with ovarian cancer. Next generation sequencing–based characterization of the genomic landscape of mUC will be presented. Clinical trial information: NCT03397394.

Histologic subtype and response to immune checkpoint inhibitor (ICI) therapy in advanced urothelial cancer (aUC)

495

Background: Urinary tract cancer can be pure urothelial carcinoma (PUC) or variant UC (VUC, defined here as pure non-UC or mixed UC + non-UC); VUC often has a worse prognosis. Little is known about outcomes for patients (pts) with VUC receiving ICI. We hypothesized that VUC does not compromise ICI efficacy in pts with aUC. Methods: We performed a retrospective cohort study across 18 institutions. Demographic, clinicopathologic, treatment and outcomes data was collected for pts with aUC who received ICI. Pts were stratified to PUC vs VUC; VUC was further divided by histologic subtype, i.e. squamous, neuroendocrine (NE), etc. We compared overall response rate (ORR) using logistic regression, progression free survival (PFS) and overall survival (OS) using Kaplan-Meier and Cox proportional hazards; p<0.05 was significant. Results: 519 consecutive pts were identified; 405, 414 and 411 included in ORR, OS and PFS analyses, respectively. Demographics included mean age 69, 27% female, 66% ever smokers, 15% upper tract disease, 54% with extirpative surgery. ORR to ICI between pts with PUC and VUC was comparable (both 28%, p=0.86) without significant differences for individual subtypes vs PUC. Median OS for pts with PUC was 11.0 vs 9.9 mo for VUC (p=0.45), but only 3.7 mo for those with NE features (HR=3.01 [95% CI 1.63-5.57] vs PUC, p<0.001). Median PFS was 4.1 vs 5.2 mo for PUC vs VUC (p=0.46) and 2.8 mo for NE (HR=1.85 [95% CI 0.94-3.61] vs PUC, p=0.07). Conclusions: ORR to ICI and OS were comparable across histologic types; however, OS was shorter for tumors with NE features. VUC should not exclude pts from receiving ICI in routine practice and clinical trials.[Table: see text]

The role of previous radical local treatment (RLT) on the outcome of immune checkpoint inhibitors (ICI) in patients (pts) with metastatic urothelial carcinoma (mUC)

496

Background: There is a growing interest in local treatment for metastatic solid tumors. Recently, retrospective studies have reported the potential benefit of RLT to primary bladder cancer in pts with metastatic disease. We tested the impact of previous RLT in pts with mUC treated with ICI. Methods: Data from pts with mUC treated with ICI collected between May 2013 and May 2019 using a multi-institutional database was evaluated. Stratification was made according to previous RLT with ICI versus no RLT with ICI. We defined RLT as radical surgery (RS) or ≥50 Gy of radiotherapy (RT) delivered to the bladder. The X2 test was used to determine differences in rates. Overall survival (OS) between previous RLT plus ICI (group A) versus no RLT plus ICI (group B) generated using Kaplan-Meier method was compared by log-rank test. OS was calculated from the date of initiation of ICI to the date of death. Analyses were performed using SPSS v21. Results: A total of 115 pts with mUC were treated with ICI, 62 (53.9%) previously were treated with RS, 7(6.1%) RT and 46 (40%) no received RLT. ICI prescribed were atezolizumab (55.7%), pembrolizumab (16.5%), durvalumab (11.3%), durvalumab/tremelimumab (7.8%), nivolumab (5.2%) and avelumab (3.5%). The disease control rate (CR [6.9%] +PR [9.6%] +SD [14.1%]) was higher for pts with previous RLT compared to those pts who did not receive RLT (CR [3.2%] + PR [5.8%] + SD [6.4%](P=0.325). Median OS was 11.23 mo (95% CI; 6.02-16.44) and 7.95 mo (95%IC; 5.15-10.75) for group A and group B, respectively (P=0.481). Conclusions: This multicenter cohort suggests that previous RLT might play an impact for control disease in pts with mUC treated with ICI. Although this is hypothesis generating, the true value of this approach remains to be demonstrated in prospective studies.

Effect of concurrent proton pump inhibitors (PPI) use in patients (pts) treated with immune checkpoint inhibitors (ICI) for metastatic urothelial carcinoma (mUC)

500

Background: PPI are widely used in pts with cancer. PPI are associated with anti-inflammatory properties and direct effects on neutrophils and monocytes that might prevent inflammation. We investigate the role of PPI on outcomes of pt receiving ICI in mUC. Methods: Medical records from pts with mUC treated with ICI from May 2013 to May 2019 using a multi-institutional database was evaluated. Use of PPI was defined: 30 days prior, during the treatment and 30 days after the last dose of ICI. ORR were assessed according to RECIST v1.1. The X2 test was used to determine differences in rates. PFS and OS were estimated using Kaplan-Method and long rank test was used to assess differences between groups. All analyses were performed using SPSS v21. Results: Overall, 115 pts received therapy with ICI. Of these pts, 20 were not included due to the absence of information about PPI. Thus, 95 pts were included for the analysis. 50 (52.6%) pts received PPI. Median age was 68 years, 79 pts (83.2%) were male, 78 pts (82.1%) had ECOG PS 0-1, 20 pts (21.1%) had liver metastasis and 36 pts (37.9%) received ICI treatment as frontline therapy. ICI prescribed were atezolizumab (58.9%), pembrolizumab (17.9%), durvalumab (12.6%), nivolumab (6.3%) and durvalumab/tremelimumab (4.2%). Pts with no PPIs use had higher ORR (CR [8.9%] +PR [14.4%]) compared to those pt who use PPIs (CR [4.4%] + PR [8.9%]) (P=0.197). Median PFS was 10.05 mo (95% CI: 3.86-16.27) for non PPI users and 3.87 mo (95% CI:1.84-5.91) for PPI users (P=0.04). Median OS was 19.71 mo (95% IC:8.93-30.49) for non PPI users and 7.9 mo (4.4-11.45) for PPI users (P=0.072). Conclusions: We have observed shorter PFS and trend toward lower OS and ORR for PPI users. The real impact of PPI should be confirmed in prospective studies.

The Challenge of Managing Bladder Cancer and Upper Tract Urothelial Carcinoma: A Review with Treatment Recommendations from the Spanish Oncology Genitourinary Group (SOGUG)

Bladder cancer is the fourth most common cancer in men and the ninth most common in women in the Western world. The management of bladder carcinoma requires a multidisciplinary approach. Optimal treatment depends on several factors, including histology, stage, patient status, and possible comorbidities. Here we review recent findings on the treatment of muscle-invasive bladder carcinoma, advanced urothelial carcinoma, upper tract urothelial carcinoma, non-urothelial carcinoma, and urologic complications arising from the disease or treatment. In addition, we present the recommendations of the Spanish Oncology Genitourinary Group for the treatment of these diseases, based on a focused analysis of clinical management and the potential of current research, including recent findings on the potential benefit of immunotherapy. In recent years, whole-genome approaches have provided new predictive biomarkers and promising molecular targets that could lead to precision medicine in bladder cancer. Moreover, the involvement of other specialists in addition to urologists will ensure not only appropriate therapeutic decisions but also adequate follow-up for response evaluation and management of complications. It is crucial, however, to apply recent molecular findings and implement clinical guidelines as soon as possible in order to maximize therapeutic gains and improve patient prognosis.

Clinical outcome after progressing to frontline and second-line Anti-PD-1/PD-L1 in advanced urothelial cancer

BACKGROUND

Immune checkpoint inhibitors (ICIs) are approved for first-line (cisplatin unfit, PD-L1+) and platinum-refractory urothelial carcinoma (UC). Still, most patients experience progressive disease (PD) as the best response. Although higher response rates to subsequent systemic treatment (SST) have been described, post-PD outcome data are scarce.

OBJECTIVE

To examine the outcome of UC patients who received SST and no SST after progressing to ICIs.

DESIGN, SETTING, AND PARTICIPANTS

A retrospective analysis of UC patients progressing to frontline or later-line anti-PD-1/PD-L1 therapy in 10 European institutions was conducted between March 2013 and September 2017.

INTERVENTION

Post-PD management as per standard practice.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Overall survival (OS) was analyzed with a Kaplan-Meier model. Cox regression was used for multivariate analysis (MV). Impact of SST on OS was examined with a time-varying covariate model.

RESULTS AND LIMITATIONS

A total of 270 UC patients with PD to ICIs (69 frontline, 201 later line) were analyzed. Of the patients, 57% of frontline-ICI-PD and 34% of later-line-ICI-PD patients received SST, and SST had an impact on OS in MV (frontline: hazard ratio [HR] 0.22, 95% confidence interval [CI] 0.10-0.51, p <  0.001; later line: HR 0.22, 95% CI 0.13-0.36, p <  0.001). In the frontline-ICI-PD group, median OS with and without SST was 6.8 mo (95% CI 5.0-8.6) and 1.9 mo (95% CI 0.9-3.0), respectively. High disease burden (three or more metastatic sites: HR 2.49, p =  0.03; simultaneous liver/bone metastases: HR 3.93, p =  0.03) predicted worse survival. In later-line-ICI-PD group, response to ICIs (HR 0.37, p =  0.03), longer exposure to ICIs (HR 0.89, p =  0.002), and bone metastasis (HR 2.42, p <  0.001) predicted survival. The retrospective nature of this study and a lack of certain parameters limit the interpretation of our analysis.

CONCLUSIONS

Patients progressing to frontline ICIs are at risk of early death, excluding them from experiencing potential benefit from chemotherapy PATIENT SUMMARY: Our analysis suggests that outcomes after failing immunotherapy are poor, particularly in UC patients who received no prior chemotherapy.

Atezolizumab (MPDL3280A) Monotherapy for Patients With Metastatic Urothelial Cancer: Long-term Outcomes From a Phase 1 Study

Importance

Atezolizumab (anti-programmed death ligand 1) has demonstrated safety and activity in advanced and metastatic urothelial carcinoma, but its long-term clinical profile remains unknown.

Objective

To report long-term clinical outcomes with atezolizumab therapy for patients with metastatic urothelial carcinoma.

Design, Setting, and Participants

Patients were enrolled in an expansion cohort of an ongoing, open-label, phase 1 study. Median follow-up was 37.8 months (range, >0.7 to 44.4 months). Enrollment occurred between March 2013 and August 2015 at US and European academic medical centers. Eligible patients had measurable disease per Response Evaluation Criteria in Solid Tumors version 1.1, Eastern Cooperative Oncology Group performance status 0 to 1, and a representative tumor sample. Programmed death ligand 1 expression on immune cells was assessed (VENTANA SP142 assay).

Interventions

Atezolizumab was given intravenously every 3 weeks until unacceptable toxic effects, protocol nonadherence, or loss of clinical benefit.

Main Outcomes and Measures

Primary outcome was safety. Secondary outcomes included objective response rate, duration of response, and progression-free survival. Response and overall survival were assessed in key baseline subgroups.

Results

Ninety-five patients were evaluable (72 [76%] male; median age, 66 years [range, 36-89 years]). Forty-five (47%) received atezolizumab as third-line therapy or greater. Nine patients (9%) had a grade 3 to 4 treatment-related adverse event, mostly within the first treatment year; no serious related adverse events were observed thereafter. One patient (1%) discontinued treatment due to a related event. No treatment-related deaths occurred. Responses occurred in 26% (95% CI, 18%-36%) of patients. Median duration of response was 22.1 months (range, 2.8 to >41.0 months), and median progression-free survival was 2.7 months (95% CI, 1.4-4.3 months). Median overall survival was 10.1 months (95% CI, 7.3-17.0 months); 3-year OS rate was 27% (95% CI, 17%-36%). Response occurred in 40% (95% CI, 26%-55%; n = 40) and 11% (95% CI, 4%-25%; n = 44) of patients with programmed death ligand 1 expression of at least 5% tumor-infiltrating immune cells (IC2/3) or less than 5% (IC0/1), respectively. Median overall survival in patients with IC2/3 and IC0/1 was 14.6 months (95% CI, 9.0 months to not estimable) and 7.6 months (95% CI, 4.7 to 13.9 months), respectively.

Conclusions and Relevance

Atezolizumab remained well tolerated and provided durable clinical benefit to a heavily pretreated metastatic urothelial carcinoma population in this long-term study.

Trial Registration

clinicaltrials.gov Identifier: NCT01375842.

Abstract CT179: ATLAS: A Phase II, open-label study of rucaparib in patients with locally advanced or metastatic urothelial carcinoma

Background: For patients with metastatic urothelial carcinoma (mUC) that has progressed on or after platinum-based chemotherapy (cisplatin or carboplatin) and/or immune checkpoint inhibitors, there are currently no standard treatments, emphasizing the urgent unmet need for additional treatment options. Based on analysis of The Cancer Genome Atlas bladder cancer dataset, ≈60% of muscle invasive bladder tumors have homologous recombination (HR) deficiency (HRD), as defined by high genomic loss of heterozygosity (LOH) or a deleterious mutation in a DNA repair pathway gene. Poly(ADP-ribose) polymerase (PARP) inhibitors such as rucaparib exert their antitumor activity through synthetic lethality in cancer cells with HRD. Tumors with HRD have been shown to be sensitive to PARP inhibitors in breast, ovarian, and prostate cancers, and PARP inhibitors are approved for the treatment of patients with breast or ovarian cancer. Although there are little data on their activity in mUC, we hypothesize that PARP inhibition may have antitumor activity in this tumor type. The ATLAS (NCT03397394) trial is evaluating the efficacy and safety of the PARP inhibitor rucaparib as monotherapy for patients with locally advanced (unresectable) urothelial carcinoma or mUC previously treated with 1-2 anticancer treatments for advanced/metastatic disease.

Methods: Eligible patients must have received 1-2 prior treatments (eg, platinum-based chemotherapy, immune checkpoint inhibitor, and/or clinical trial agent) and have radiographic progression, measurable disease (RECIST version 1.1), and adequate organ function. Tumor HRD is not required as rucaparib may potentially benefit patients with HR-proficient or HR-deficient tumors; however, fresh tumor or recently obtained archival tissue is mandatory for central HRD profiling. Prior PARP inhibitor treatment is an exclusion criterion. All patients will receive rucaparib monotherapy (600 mg BID) until disease progression or other reason for discontinuation. The primary endpoint is confirmed objective response rate (investigator assessed per RECIST version 1.1) in the intent-to-treat and HRD-positive (signature based on tumor genomic LOH) populations. Secondary endpoints include response duration, progression-free survival, overall survival, safety, and pharmacokinetics. Exploratory endpoints include evaluating plasma and tumor samples for biomarkers associated with response and resistance to rucaparib. The study has &gt;90% power to reject the null hypothesis (P=0.10) at a one-sided 5% significance level if the true response rate for rucaparib is 20%. ATLAS is currently enrolling at ≈65 sites in 6 countries (France, Germany, Italy, Spain, United Kingdom, and United States), with a target enrollment of 200 patients.

Citation Format: Petros Grivas, Min Yuen Teo, Nicholas Vogelzang, Ajjai Alva, Yousef Zakharia, Nabil Adra, Alexandra Drakaki, Arif Hussain, Rafael Morales-Barrera, Andrea Necchi, Alejo Rodriguez-Vida, Susan Feyerabend, Sumati Gupta, Debra H. Josephs, Yohann Loriot, Sandy Srinivas, Kenton Wride, Daleen Thomas, Rachel Dusek, Andrew D. Simmons, Dale Nepert, Simon Chowdhury. ATLAS: A Phase II, open-label study of rucaparib in patients with locally advanced or metastatic urothelial carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr CT179.

Translational study associated to a phase II study evaluating the activity of pazopanib in patients (pts) with advanced/metastatic liposarcoma (LPS): A joint Spanish Sarcoma Group (GEIS) and German Interdisciplinary Sarcoma Group (GISG) study

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Background: GEIS 30 was a phase II study showing moderate activity of pazopanib in well-differentiated/dedifferentiated LPS (cohort A:37 pts, Progression free Survival (PFS) at 12 weeks (w) 43.2%) and no activity in Myxoid/round cell LPS (cohort B: 15 pts, PFS at 12w 13.3%). The present study aims to identify tumor and plasma biomarkers that are differently expressed in long responders (LRs) PFS > 24 w. Methods: Serum samples and paraffin-blocks at diagnosis were collected for 28 pts in cohort A and 11 in B. A total of 13 pts were LRs. Serum samples were obtained at baseline, after 3 w of treatment and at progression. A panel of 15 cytokines and growth factors were evaluated using Luminex technology (Millipore). Paraffin-blocks were evaluated for microvessel density (MVD) by CD31 immunostaining and Image Pro-Plus 7.0 Image Analysis System (Media-Cybernetics). For RNA expression analysis, the Oncology Biomarker Panel with probes for 2559 transcripts was used (HTG Molecular Diagnostics). Results: Serum cytokines showed that expression of angiopoietin (AGO) and BMP9 decreases during treatment, whereas GCSF increases. In addition, AGO and BMP overexpression at baseline was associated with worse prognosis in arm A (p = 0.09) and B (p = 0.01) respectively. No differences between study arms and outcome were appreciated by MVD. Gene expression revealed differences in some immunomodulators: PDL-1 was correlated with serum cytokines VEGFD (p = 0.04) and LEPTIN (p = 0.02); and PD-1 with VEGFD (p = 0.04), LEPTIN (p = 0.02), VEGFA (p = 0.02) and ANGIO (p = 0.03). PD1, in addition,was overexpressed in LRs (p = 0.05). Interestingly, three groups were identified in cohort A according to gene expression: Cluster 1, characterized by short-responder patients with the shortest overall survival, whereas cluster 3 (40% LRs) and 2 (63.6% LRs) showed longer survival rates (14.3%, 45.5% and 30% respectively) (p = 0.001). Conclusions: Gene expression profiling unveils three WD/DD-LPS biotypes according to their response to pazopanib, which could be potentially used to select pts for treatment

Impact of immune-related adverse events on survival in patients with metastastic urothelial carcinoma treated with immune-checkpoint inhibitors

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Background: Immune-checkpoints inhibitors (ICIs) represents the standard of care for platinum-pretreated advanced urothelial cancer patients (pts). By enhancing T-cell activation, a unique spectrum of inflammatory side effects has emerged, also known as immune-related adverse events (irAEs). Data regarding the association between irAEs and pts outcomes are conflicting. Here we conducted a retrospective analysis to investigate the association between irAEs profile and disease outcome in metastastic urothelial carcinoma (mUC) pts. Methods: Medical records from pts with mUC included in clinical trials between July 2013 and June 2018 and treated with ICIs were reviewed. Pts previously treated with platinum-based chemotherapy or cisplatin ineligible pts who had not been previously treated with chemotherapy were included. Clinical responses were assessed as complete response (CR), partial response (PR), stable disease (SD), and progressive disease (PD) according to RECIST v1.1. Adverse events were graded based CTCAE v4.03. Overall survival (OS) was calculated from the date of initiation of ICI to the date of death. X2 test was used to determine differences in rates. OS was estimated using Kaplan-Method and long rank test was used to assess differences between groups. All analyses were performed using SPSS v21. Results: From a total of 52 pts, 44 (84.6%) were treated with ICI monotherapy and 8 (15.3%) in combination (anti-CTLA4 or targeted therapy). Median age was 65 years, 42 pts (80.8%) were male, 44 patients (84.6%) had ECOG PS 0-1, 14 pts (26.9%) had liver metastasis. Overall irAEs were observed in 30 pts (57.7%) and 10 pts (19.2%) developed grade 3/4 irAES. Most common grade 3/4 irAEs were diarrhea (6.6%), rash (6.6%) and hepatitis (6.6%). Disease control rate (CR [26%]+PR[33%]+SD[20%]) was higher for patients with irAEs compared to those patients who did not developed irAEs (CR [13.6%]+PR[0%]+SD[22.7%], this difference was statically significant (P = 0.002). Median OS was 11.23 mo (CI 95%, 3.76-18.70) for the overall cohort, while median OS was 21.91 mo for those patients with irAEs compared to 6.47 mo in patients who did not developed irAEs (P = 0.004). Conclusions: In this analysis we found that the development of irAEs was a strong predictor of improved OS in mUC patients treated with ICI.