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.

Ibrutinib combination therapy for advanced gastrointestinal and genitourinary tumours: results from a phase 1b/2 study

BACKGROUND

Ibrutinib, a first-in-class inhibitor of Bruton's tyrosine kinase, is approved for the treatment of various B-cell malignancies and chronic graft-versus-host disease. Based on encouraging preclinical data, safety and efficacy of ibrutinib combined with companion drugs for advanced renal cell carcinoma (RCC), gastric/gastroesophageal junctional adenocarcinoma (GC), and colorectal adenocarcinoma (CRC) were evaluated.

METHODS

Ibrutinib 560 mg or 840 mg once daily was administered with standard doses of everolimus for RCC, docetaxel for GC, and cetuximab for CRC. Endpoints included determination of the recommended phase 2 dose (RP2D) of ibrutinib in phase 1b and efficacy (overall response rate [ORR] for GC and CRC; progression-free survival [PFS] for CRC) in phase 2.

RESULTS

A total of 39 (RCC), 46 (GC), and 50 (RCC) patients were enrolled and received the RP2D. Safety profiles were consistent with the individual agents used in the study. Confirmed ORRs were 3% (RCC), 21% (GC), and 19% (CRC). Median (90% CI) PFS was 5.6 (3.9-7.5) months in RCC, 4.0 (2.7-4.2) months in GC, and 5.4 (4.1-5.8) months in CRC.

CONCLUSIONS

Clinically meaningful increases in efficacy were not observed compared to historical controls; however, the data may warrant further evaluation of ibrutinib combinations in other solid tumours.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT02599324.

Off-label drug use during the COVID-19 pandemic in Africa: topic modelling and sentiment analysis of ivermectin in South Africa and Nigeria as a case study

Although rejected by the World Health Organization, the human and even veterinary formulation of ivermectin has widely been used for prevention and treatment of COVID-19. In this work we leverage Twitter to understand the reasons for the drug use from ivermectin supporters, their source of information, their emotions, their gender demographics, and location information, in Nigeria and South Africa. Topic modelling is performed on a Twitter dataset gathered using keywords 'ivermectin' and 'ivm'. A model is fine-tuned on RoBERTa to find the stance of the tweets. Statistical analysis is performed to compare the stance and emotions. Most ivermectin supporters either redistribute conspiracy theories posted by influencers, or refer to flawed studies confirming ivermectin efficacy in vitro. Three emotions have the highest intensity, optimism, joy and disgust. The number of anti-ivermectin tweets has a significant positive correlation with vaccination rate. All the provinces in South Africa and most of the provinces of Nigeria are pro-ivermectin and have higher disgust polarity. This work makes the effort to understand public discussions regarding ivermectin during the COVID-19 pandemic to help policy-makers understand the rationale behind its popularity, and inform more targeted policies to discourage self-administration of ivermectin. Moreover, it is a lesson to future outbreaks.

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.

A correlative biomarker study and integrative prognostic model in chemotherapy-naïve metastatic castration-resistant prostate cancer treated with enzalutamide

BACKGROUND

There is a considerable need to incorporate biomarkers of resistance to new antiandrogen agents in the management of castration-resistant prostate cancer (CRPC).

METHODS

We conducted a phase II trial of enzalutamide in first-line chemo-naïve asymptomatic or minimally symptomatic mCRPC and analyzed the prognostic value of TMPRSS2-ERG and other biomarkers, including circulating tumor cells (CTCs), androgen receptor splice variant (AR-V7) in CTCs and plasma Androgen Receptor copy number gain (AR-gain). These biomarkers were correlated with treatment response and survival outcomes and developed a clinical-molecular prognostic model using penalized cox-proportional hazard model. This model was validated in an independent cohort.

RESULTS

Ninety-eight patients were included. TMPRSS2-ERG fusion gene was detected in 32 patients with no differences observed in efficacy outcomes. CTC detection was associated with worse outcome and AR-V7 in CTCs was associated with increased rate of progression as best response. Plasma AR gain was strongly associated with an adverse outcome, with worse median prostate specific antigen (PSA)-PFS (4.2 vs. 14.7 m; p < 0.0001), rad-PFS (4.5 vs. 27.6 m; p < 0.0001), and OS (12.7 vs. 38.1 m; p < 0.0001). The clinical prognostic model developed in PREVAIL was validated (C-Index 0.70) and the addition of plasma AR (C-Index 0.79; p < 0.001) increased its prognostic ability. We generated a parsimonious model including alkaline phosphatase (ALP); PSA and AR gain (C-index 0.78) that was validated in an independent cohort.

CONCLUSIONS

TMPRSS2-ERG detection did not correlate with differential activity of enzalutamide in first-line mCRPC. However, we observed that CTCs and plasma AR gain were the most relevant biomarkers.

Does the time-of-day administration of immune checkpoint inhibitors affect efficacy in patients with metastatic renal cell carcinoma? A single-center study

681

Background: Immune checkpoint inhibitors (ICI) are the standard of care for metastatic renal cell carcinoma (mRCC). Circadian rhythm drives organisms to properly predict and react to cyclical changes in the environment, and also affects the adaptive immune response. Here, we study the relationship between time-of-day ICI administration and outcomes in mRCC patients (pts). Methods: This is a single-center retrospective study of ICI-treated mRCC pts diagnosed from January 2014 to March 2022. Day and time of each ICI infusion (inf) for each pt were obtained from the pharmacy records. Proportion of ICI inf administered after 4:30 pm (ICI430) was calculated based on a prior publication (Quian, Lancet Oncol 2021). The primary outcome was overall survival (OS), and secondary endpoints were time on treatment (TOT), time to next treatment (TNT), and overall response rate (ORR). The proportion of ICI430 as a continuous variable, and the dichotomized data (≥20% and ≥50%) were correlated with OS, TOT and TNT by Kaplan-Meier analysis and Cox regression, and with ORR by logistic regression. Results: Overall, 104 pts and 1763 inf were analyzed (Table). 48 pts were treated with 1st line (1L) ICI. 903 inf were administered (median 12 inf per pt, 1 - 111), 146 (15.6%) after 4:30 pm. 12 (25%) and 2 (4.2%) pts received ≥ 20% and ≥ 50% ICI430. Due to the small number of events (5 deaths and 15 progressions), of ICI430, and heterogeneity of treatments in 1L, we focus on pts treated with 2nd line (2L) ICI. 56 pts were treated with ICI in ≥2L. 860 inf were administered (median 8 inf per pt, 1 - 123), 180 (20.9%) after 4:30 pm. 15 (34.1%) and 9 (20.5%) pts received ≥20% and ≥50% ICI430. Pts who received ≥20% after 4:30pm, received fewer inf (7 vs. 16, p=0.022), had a worse TOT (4.3 vs. 9 m, HR 2.5, p=0.013), a trend to a worse TNT (6.3 vs. 10.5 m, HR 1.9, p=0.06) and a worse OS (16.9 vs. 56.1 m, HR 3.1, p=0.01). Similar results were obtained when using ≥ 50% ICI430 as the cut-off (TOT, 2 vs. 9m, p=0.007; TNT 4.7 vs. 10.5m, p=0.05; OS 16.9 vs. 36.6m, p=0.1), as well as higher frequency of progressive disease (85.7 vs. 21.9%, p=0.006). A significant association with OS (HR 1.02, p=0.03) was shown when analyzing ICI430 as a continuous variable, meaning a 16% increase in the risk of death for each 10% increment of ICI inf after 4:30 pm. Conclusions: Administration of ≥2L ICI after 4:30 pm is associated with poor overall survival. Our results could have a direct impact on pt survival and organization of outpatient clinics, but further research is needed. [Table: see text]

PBRM1 genomic alterations as a predictive biomarker to immune checkpoint inhibitors (ICI) and/or anti-angiogenic therapies (anti-VEGF) in metastatic renal cell carcinoma (mRCC): A systematic review and meta-analysis

e16515

Background: Combination therapy with ICI and anti-VEGF has become the standard first-line (1L) therapy for metastatic clear cell RCC (mccRCC). However, about 25% of patients (pts) are long responders to anti-VEGF monotherapy. PBRM1 genomic alterations (ga) are present in around 40% mccRCC pts and contradictory results have been reported about its role as a predictive biomarker. We performed a systemic review and meta-analysis to assess the role of PBRM1 ga as a predictive biomarker of response to ICI, anti-VEGF, or its combination. Methods: A systematic review of PubMed, EMBASE, Cochrane, and Web of Science databases was performed (February 2022) to identify studies involving mRCC pts who received systemic therapy and had PBRM1 status and clinical outcomes reported. Study design, baseline characteristics, treatment data, and hazard ratios (HRs) with 95% confidence intervals (CI) for each clinical outcome were extracted. HRs were combined across studies using a random effect model. The primary endpoint was to correlate PBRM1 status with progression-free survival (PFS) to anti-VEGF, ICI, or its combination. Results: The systematic review included 12 out of 892 publications (n = 6528 pts), 98% (n = 6372) mccRCC; 3297 pts (51%) treated with anti-VEGF monotherapy, 1574 (24%) ICI (PD-L1 (n = 1019, 65%) or CTLA4 + anti PD-L1 (n = 555, 35%)), 997 pts (15%) anti-VEGF + ICI, and 660 pts (10%) with other therapies (e.g., mTORi or INF). PBRM1 status was assessed by NGS in 3841 pts (59%) and detected in 1595 (41%). Nine out of 12 publications were considered for the meta-analysis; excluding those with duplicated pts or lack of information. Six studies (n = 2593 pts) evaluated PBRM1 status in first-line (1L) therapies, including anti-VEGF in monotherapy (n = 1487, 57%) and ICI (n = 1106, 43%; combined w/anti-VEGF (n = 773), w/CTL4 (n = 262) or in monotherapy (n = 71)). In 1L setting, PBRM1 ga pts had longer PFS under monotherapy with anti-VEGF ( PBRM1 ga 44%; HR = 0.74 (95% CI, 0.62 - 0.88), p < 0.01) but not under ICI ( PBRM1 ga = 42%; HR = 1 (95% CI, 0.85 - 1.17), p = 0.38) nor ICI + anti-VEGF treatment ( PBRM1 ga = 33.5%; HR = 0.93 (95% CI, 0.73 - 1.18), p = 0.56). Two studies evaluated PBRM1 status in second line (2L) ICI-treated mRCC pts (n = 517 pts). PBRM1 ga pts had longer PFS under ICI in 2L ( PBRM1 ga = 36%, HR = 0.64 (95% CI, 0.49 - 0.83), p = 0.0007). Conclusions: mRCC pts with PBRM1 ga showed longer PFS to 1L anti-VEGF and 2L ICI therapy, supporting its role as a predictive biomarker. Anti-VEGF + ICI combination de-escalation strategies merits further investigation in PBRM1 ga mRCC patients.

Estrogen receptor β and TMPRSS2-ERG expression association with clinical outcomes in metastatic hormone-sensitive prostate cancer

5077

Background: TMPRSS2-ERG fusion has been associated with estrogen receptor (ER) signalling in prostate cancer (PC). The isoform beta of ER (ERβ), encoded by ESR2, is considered anti-proliferative and tumor-suppressive. In preclinical studies, ESR2 has shown an inhibitory role towards TMPRSS2-ERG, resulting in decreased proliferation and tumor regression. In this clinical series, we sought to investigate the correlation between TMPRSS2-ERG and ESR2 expression and its impact on clinical outcomes in a cohort of patients (pts) with metastatic hormone-sensitive PC (mHSPC). Methods: This is a multicenter retrospective biomarker study. TMPRSS2-ERG and ESR2 were tested in total mRNA from FFPE tumor samples by nCounter platform (Nanostring Technologies). TMPRSS2-ERG and ESR2 expression were correlated with castration-resistant PC free survival (CRPC-FS) and overall survival (OS) by Kaplan Meier and multivariate Cox modeling. R (v.3.6.3) software was used for statistical analysis. Results: 218 mHSPC pts were included: 125 received androgen deprivation therapy (ADT) with Docetaxel and 93 ADT alone. Median age was 66.4 years (range 46.3-84.6), 75.7% ( N= 165) presented with de novo mHSPC, 15.1% ( N= 33) had visceral metastasis and 68.3% ( N= 149) had high volume disease. Median follow-up was 38.8 months (m) (range 6.7-223.5) and 189 pts (86.7%) developed CRPC. Five pts were excluded due to lack of follow-up. Median time to CRPC was 18.8 m (95% CI 15.8-20.5) and median OS was 48.8 m (95% CI 43.2-59.1). Pts were grouped according to TMPRSS2-ERG fusion detection in TE positive (TE+) ( N= 108, 49.5%) and TE negative (TE-) ( N= 110, 50.5%) and according to ESR2 expression levels segregated into tertiles in ESR2 high (ESR2+) ( N= 74, 33.9%) or ESR2 low-mid (ESR2-) ( N= 144, 66.1%). TE+ status was associated to higher ESR2 levels ( P= 0.03). The TE+/ESR2+ group showed longer CRPC-FS and OS, compared with the other groups, as shown in the table. TE+/ESR2 expression was independently associated with longer CRPC-FS (HR 0.3, 95% CI 0.2-0.5, P< 0.001) and OS (HR 0.3, 95% CI 0.2-0.5, P< 0.001). Moreover, a significant interaction between treatment (ADT vs ADT+Docetaxel) and TE+/ESR2+ status related to CRPC-FS was found (HR: 0.38, P= 0.014), suggesting that TE+/ESR2+ pts may benefit more from ADT than from the combination of ADT+Docetaxel. Conclusions: Our study suggests a protective role of ESR2 within a subgroup of mHSPC pts characterized by TMPRSS2-ERG fusion, which warrants further investigation of ESR2 as a prognostic factor, for treatment selection and as a potential pathway for targeted treatment in PC. [Table: see text]

Futibatinib plus pembrolizumab in patients (pts) with advanced or metastatic urothelial carcinoma (mUC): Preliminary safety results from a phase 2 study

501

Background: Immune checkpoint inhibitors (ICIs), including pembrolizumab, are among the few treatment options available for platinum-ineligible pts with mUC, but only 25–30% of pts achieve responses with ICIs. FGFR DNA alterations (in 15–20% of mUCs) may contribute to poor responses to ICIs, and FGFR inhibition may sensitize tumors to ICIs by direct action on cancer cells or by altering the tumor microenvironment. In an open-label phase 2 study (NCT04601857), futibatinib, a highly selective, potent, irreversible FGFR1–4 inhibitor with activity in FGFR-deregulated tumors, is being assessed in combination with pembrolizumab in pts with mUC. Here, we report preliminary findings from the safety lead-in phase. Methods: Eligible pts (≥18 y; ECOG PS ≤1) had mUC, were treatment naive in the advanced/metastatic setting, and unfit for, intolerant to, or refusing platinum-based chemotherapy. Prior anti–PD-1/PD-ligand 1/2 or FGFR inhibitor therapy were not permitted. Pts (regardless of FGFR alteration status) were first enrolled in a safety lead-in and received futibatinib 20 mg orally once daily (QD) and pembrolizumab 200 mg IV every 21 d. Dose-limiting toxicities (DLTs) were assessed during the first 21-d treatment cycle. Results: As of September 27, 2021, 6 pts were enrolled in the safety lead-in. Median age was 73.5 y (range, 46–84 y) and 17% (1/6) of pts had an ECOG PS of 1. Median duration of treatment was 48 d (range, 21–141 d) with futibatinib and 35 d (1–114 d) with pembrolizumab. Two pts (33%) remained on treatment at data cutoff. Adverse events (AEs) were reported in all 6 pts; AEs in > 2 pts were diarrhea (83%), hyperphosphatemia (67%), increased aspartate aminotransferase (50%), and pruritis (50%). Grade 3 AEs were reported in 2/6 pts: increased aspartate aminotransferase, maculopapular rash, myositis (17% each). There were no grade 4–5 AEs. AEs led to any study drug discontinuation in 3 pts, dose interruption in 3 pts, and dose modification in 3 pts. All 6 pts were evaluated for DLTs after 1 treatment cycle; no DLTs were reported. Conclusions: Preliminary safety results support tolerability of futibatinib plus pembrolizumab in platinum-ineligible pts with mUC. As no DLTs were observed in the safety lead-in, the recommended dose of futibatinib in combination with pembrolizumab is 20 mg QD. Enrollment in pts with or without FGFR alterations is ongoing to evaluate antitumor activity by FGFR alteration status. Clinical trial information: NCT04601857.

A randomized phase 2 trial to evaluate the antitumor activity of enzalutamide (EZ) and talazoparib (TALA) for the treatment of metastatic hormone-naïve prostate cancer (mHNPC): ZZFIRST

TPS209

Background: Multiple lines of evidence suggest a crosstalk between androgen receptor (AR) signaling and DNA damage repair (DDR) in prostate cancer. Co-targeting both pathways in mHNPC can result in a clinically relevant synergistic effect. ZZFIRST trial is evaluating the combination of TALA –a poly(ADP-ribose) polymerase inhibitor– and EZ –an AR signaling inhibitor– in mHNPC patients. Methods: This is a multicenter, open-label, randomized, investigator-initiated phase 2 clinical trial. Men aged ≥18 years with histologically confirmed mHNPC, an ECOG performance status of 0-1, and a prostate-specific antigen (PSA) ≥4 ng/mL at enrolment are eligible. Patients must have not received previous systemic treatment for locally advanced or mHNPC. A total of 54 patients will start treatment with EZ 160 mg/day for 2 28-day cycles in addition to standard androgen-deprivation therapy (ADT). Patients are then randomized and stratified based on homologous recombination gene alterations on a 1:2 ratio to either continue EZ 160 mg/day, or to receive EZ 160 mg/day plus TALA 0.5 mg/day. In both arms, patients will continue ADT throughout the trial. Treatment will continue until progressive disease (PD) or unacceptable toxicity. PSA will be determined every 4 weeks and radiological tumor extend will be assessed at screening and every 8 weeks for the 6 initial months of treatment and every 12 weeks thereafter until PD. Primary endpoint is PSA-complete response defined as the percentage of patients with PSA < 0.2 ng/mL at 12 months of therapy. Secondary endpoints include PSA-complete response at any time point and at month 7, PSA response ( < 4 ng/ml) at 7 and 12 months, PSA-progression-free survival (PSA-PFS), radiologic PFS, time to castration resistance based on PSA-PFS and rPFS, and overall survival. Safety will be assessed as per NCI-CTCAE 5.0. Exploratory endpoints include analysis of transcriptional changes in AR and DDR pathways and assessment of genomic signatures on tumor and liquid biopsies collected at baseline, 4 weeks, and PD. An imaging sub-study of whole-body diffusion weighted MRI will help to further study antitumor activity and drug resistance mechanisms. This trial was opened to accrual in July 2020. Currently 44 patients have been enrolled (with 37 randomized by cycle 3 day 1) out of 54 expected. Analysis will be assessed with the exact binomial test. At least 11 patients must maintain PSA < 0.2 ng/mL by 12 months of therapy among 32 evaluable patients in the combination arm to justify further investigation of this strategy. A drop-out rate of 10% has been considered. Clinical trial information: NCT04332744.

Phase I-II study to evaluate safety and efficacy of niraparib plus cabozantinib in patients with advanced urothelial/kidney cancer (NICARAGUA trial): Preliminary data of phase I study

490

Background: Niraparib (N) is a (PARP)-1/-2 inhibitor and Cabozantinib (C) is a tyrosine kinase (TK) inhibitor that targets VEGF signalling via inhibition of multiple TK receptors including c-MET and TAM kinases (TYRO3, AXL, MER). The c-Met receptor TK is abnormally activated and could be decrease response to PARP inhibitors. Preclinical data reveals that treatment with c-Met inhibitors renders cells more sensitive to PARP inhibition. A phase (Ph) I-II study was designed to explore the safety and efficacy of the combination of N + C in genitourinary cancers. Methods: Multicenter, open-label Ph I-II study (NCT03425201). Confirmed histopathological diagnosis of either metastatic urothelial carcinoma (mUC) or advanced clear cell renal cell carcinoma previously treated with a maximum of two previous regimens. Adequate bone marrow, liver and renal functions were required. The Ph I portion aimed to identify the maximum tolerated dose (MTD) and recommended ph II dose (RP2D). Pt received N and C p.o. once daily in 28-day cycles: Dose level 1 (DL1) N/C 100/20 mg; DL2 200/20 mg; DL3 200/40 mg; DL4 200/60 mg. A further amendment developed DL1.1 100/40 mg. Pt were accrued to each dose level in cohorts of 6 pt until the MTD was achieved (defined as highest dose at which ≤1 out of 6 pt experience a DLT, evaluated during the first 2 cycles). Results: Nineteen evaluable pt for DLT were included, 14 of them had UC. There was no DLT at DL1. Two out of the first 6 evaluable pt in DL2 had DLT (G3 thrombopenia and anemia and G3 diarrhea respectively). Upon analysis of these pt it was agreed to include 3 additional new pt for evaluation. Two pt were included with one presenting a DLT (G3 hepatic toxicity). Enrolment then continued in a new DL 1.1 cohort and 1 of 6 pts had DLT (G3 mucositis), being then considered the RP2D. No toxic deaths were reported. Six pt (32%) received at least 10 cycles and 9 pt (47%) received at least 6 cycles. Three patients (16%) achieved partial response (all of them with mUC disease) and 14 (74%) stable disease. Conclusions: N plus C combination can be safely administered with a manageable toxicity profile and preliminary efficacy was reported in mUC heavily pretreated pts. The RP2D is N 100 mg plus C 40 mg qd. Ph II study is now recruiting mUC patients. Clinical trial information: NCT03425201. [Table: see text]

Efficacy and safety of erdafitinib in patients with locally advanced or metastatic urothelial carcinoma: long-term follow-up of a phase 2 study

BACKGROUND

Erdafitinib, a pan-fibroblast growth factor receptor (FGFR) tyrosine kinase inhibitor, was shown to be clinically active and tolerable in patients with advanced urothelial carcinoma and prespecified FGFR alterations in the primary analysis of the BLC2001 study at median 11 months of follow-up. We aimed to assess the long-term efficacy and safety of the selected regimen of erdafitinib determined in the initial part of the study.

METHODS

The open-label, non-comparator, phase 2, BLC2001 study was done at 126 medical centres in 14 countries across Asia, Europe, and North America. Eligible patients were aged 18 years or older with locally advanced and unresectable or metastatic urothelial carcinoma, at least one prespecified FGFR alteration, an Eastern Cooperative Oncology Group performance status of 0-2, and progressive disease after receiving at least one systemic chemotherapy or within 12 months of neoadjuvant or adjuvant chemotherapy or were ineligible for cisplatin. The selected regimen determined in the initial part of the study was continuous once daily 8 mg/day oral erdafitinib in 28-day cycles, with provision for pharmacodynamically guided uptitration to 9 mg/day (8 mg/day UpT). The primary endpoint was investigator-assessed confirmed objective response rate according to Response Evaluation Criteria In Solid Tumors version 1.1. Efficacy and safety were analysed in all treated patients who received at least one dose of erdafitinib. This is the final analysis of this study. This study is registered with ClinicalTrials.gov, NCT02365597.

FINDINGS

Between May 25, 2015, and Aug 9, 2018, 2328 patients were screened, of whom 212 were enrolled and 101 were treated with the selected erdafitinib 8 mg/day UpT regimen. The data cutoff date for this analysis was Aug 9, 2019. Median efficacy follow-up was 24·0 months (IQR 22·7-26·6). The investigator-assessed objective response rate for patients treated with the selected erdafitinib regimen was 40 (40%; 95% CI 30-49) of 101 patients. The safety profile remained similar to that in the primary analysis, with no new safety signals reported with longer follow-up. Grade 3-4 treatment-emergent adverse events of any causality occurred in 72 (71%) of 101 patients. The most common grade 3-4 treatment-emergent adverse events of any cause were stomatitis (in 14 [14%] of 101 patients) and hyponatraemia (in 11 [11%]). There were no treatment-related deaths.

INTERPRETATION

With longer follow-up, treatment with the selected regimen of erdafitinib showed consistent activity and a manageable safety profile in patients with locally advanced or metastatic urothelial carcinoma and prespecified FGFR alterations.

FUNDING

Janssen Research & Development.

Association of androgen receptor signature and RB1, PTEN, TP53 gene expression with clinical outcome in metastatic hormone-sensitive prostate cancer treated with docetaxel and androgen deprivation therapy

5069

Background: Androgen deprivation therapy (ADT) with docetaxel or new antiandrogens has demonstrated a survival benefit in metastatic hormone-sensitive prostate cancer (mHSPC). However, treatment selection for individual patients (pts) remains a challenge. We propose that TMPRSS2-ERG and cell plasticity [neuroendocrine (NE), epithelial to mesenchymal transition (EMT)], immune-related, androgen receptor (AR) and tumor suppressor genes (TSG) ( RB1, PTEN and TP53) expression signatures may predict clinical outcome in mHSPC pts treated with ADT+docetaxel. Methods: This is a multicenter retrospective biomarker study performed in mHSPC pts treated with ADT+docetaxel. A customized panel of 184 genes was designed and tested in total mRNA from FFPE tumor samples by nCounter platform (Nanostring Technologies). Expression levels were correlated with castration resistance-free survival (CRPC-FS) (primary endpoint) and overall survival (OS) by Kaplan Meier and multivariate Cox modeling. A predictive modeling approach was performed with Bujar R package to develop a signature able to predict CRPC-FS. R (v.3.6.3) software was used for statistical analyses. Results: 136 pts were included, and 120 of them were eligible. Median age was 66.9 years (range 46.3-83.6). Gleason score was ≥ 8 in 80.8% of pts; 87.5% and 20.8% of pts had bone and visceral metastases, respectively. Median follow-up was 30.7 months (m) (range 5.5-70.6). 76 pts (63.3%) developed castration-resistant prostate cancer (CRPC). Median time to CRPC was 20 m (range 16.9-23.1) and median OS was not reached. High AR-signature expression independently correlated with longer CRPC-FS (HR 0.4, 95% CI 0.2-0.7, p = 0.003). Considering AR-signature individual gene expression, ARV7 was independently associated with shorter CRPC-FS (HR 1.7, 95% CI 1.2-2.4, p = 0.003). Low expression of all TSG ( PTEN, RB1 and TP53) independently correlated with shorter CRPC-FS (HR 0.3, 95% CI 0.2-0.7, p = 0.003) and OS (HR 0.2, 95% CI 0.1-0.5, p < 0.001). Similarly, low expression of 2 out of the 3 TSG genes or only RB1 plus PTEN were also independently associated with shorter CRPC-FS (HR 0.5, 95% CI 0.3-0.9, p = 0.015; HR 0.4, 95% CI 0.2-0.7, p = 0.003, respectively) and OS (HR 0.4, 95% CI 0.2-0.9, p = 0.027; HR 0.2, 95% CI 0.1-0.6, p = 0.001, respectively). TMPRSS2-ERG expression, NE, EMT and immune-related signatures were not associated with clinical outcome. Bujar analysis defined a 17-gene signature (including ARV7, RB1, PTEN, BRCA2 and ATM) that was able to discriminate pts at different risk of developing early CRPC. Conclusions: High AR-signature expression correlates with a longer CRPC-FS while ARV7 expression is associated with shorter CRPC-FS. Low expression of TSG is associated with an aggressive clinical evolution in mHSPC pts treated with ADT+taxanes.

A randomized phase II study of nivolumab plus ipilimumab versus standard of care in previously untreated and advanced non-clear cell renal cell carcinoma (SUNIFORECAST)

TPS4597

Background: Non-clear cell renal cell carcinomas (nccRCC) account for approximately 25% of RCC patients (pts.). Data on treatment strategies for this heterogenous group of RCC are still limited, since most clinical trials focus on clear-cell RCC (ccRCC) histology. Recently combination therapies with immune checkpoint inhibitors (IO, avelumab or pembrolizumab) and tyrosinekinaseinhibitors (TKI) (axitinib) have been approved for treatment in RCC in all International Metastatic RCC Database Consortium (IMDC) risk groups. Additionally nivolumab and ipilimumab (IO/IO) has been approved for treatment in intermediate and high risk pts. showing a significant improvement in overall response rate (ORR), progression free (PFS), and overall survival (OS) compared to sunitinib. Moreover retrospective analysis in nccRCC pts. have shown promising results for IO-based therapies as well in these entities. Methods: In this prospective randomized phase-II multicenter European trial adults with advanced or metastatic nccRCC without prior systemic therapy are eligible. Other key inclusion criteria include: available tumor tissue, Karnofsky >70% and measurable disease per RECIST 1.1. All histological diagnoses are reviewed by a central pathologist. The study plans to randomize ̃306 pts. stratified for papillary or non-papillary non-clear cell histology and by the IMDC risk score. Pts. will be randomized 1:1 to either i) nivolumab 3mg/kg intravenously (IV) plus Ipilimumab 1mg/kg IV every 3 weeks for 4 doses followed by nivolumab fixed dose 240mg IV every 2 weeks or fixed dose 480mg IV every 4 weeks or ii) standard of care therapy according to the approved schedule. Treatment will be discontinued in case of unacceptable toxicity or withdrawal of informed consent. Pts may continue treatment beyond progression, if clinical benefit is achieved and treatment is well tolerated. Primary endpoint is the OS rate at 12 months. Secondary endpoints include OS rate at 6 and 18 months, median OS, PFS, ORR and quality of life. The trial is in progress and 214 patients (132 pts with papillary, 76 pts with non-papillary histology) have been enrolled until now. Clinical trial information: NCT03075423.

Genetic profiling across multiple cancer types using molecular prescreening comprehensive gene panels offered by clinical trials (CT)

3060

Background: Genetic profiling (GP) is essential not only for understanding tumor biology but also helps to identify potential genes for targeted therapies. At the same time, selected CT provide an individual genomic profile panel during the pre-screening phase. Here, we demonstrate our experience using these panels. Methods: We selected 14 CT from our Early Drug Development Clinical Trial Unit at Hospital Clinic of Barcelona that included analysis of gene panels in tumor (Foundation One, ArcherDX, Therascreen and Sophia Genetics) or plasma (Resolution Bioscience ctDx). These panels analyzed mutations, fusions, amplifications, microsatellite instability (MSI) and tumor mutational burden (TMB), among others. We collected information about types of cancers, molecular alterations and therapies chosen according to the results of GP. The platform OncoKB (Chakravarty JCO PO, 2017) was used to define genes with potential target therapies and levels of evidence (LE) for those targets (from LE 1 –FDA-recognized biomarker predictive of response to an FDA-approved drug- to LE 4 –Compelling biological evidence supports the biomarker as being predictive of response to a drug). Descriptive statistics were used. Results: From March 2017 to January 2021 we analyzed samples from 410 patients (pts) with CNS (19.3%), urothelial (18.3%), prostate (17.6%), breast (15.4%), ovarian (9.3%), esophageal and gastric (5.4%), colorectal (4.4%), pancreas (2.7%), endometrial (2.4%), cholangiocarcinoma (1.2%), cervix (1%), HNSCC (1%), renal (1%), lung (0.5%), liver (0.2%) fallopian tube (0.2%) and paraganglioma (0.2%). 352 pts (85.8%) had at least 1 genetic alteration. The most frequently altered genes were TP53 (153 pts, 46.2%), INSR (19 pts, 22.8%), TERT (76 pts, 22%), CDKN2A (65 pts, 19.9%), FAM175A (11 pts, 19.3%), CDKN2B (54 pts, 18.1%), MLL2 (53 pts, 17.7%), PTEN (52 pts, 16%), MTAP (45 pts, 15.7%), PIK3CA (52 pts, 15%) and ATM (55 pts, 14.4%). TMB ranged from 0 to 76.9 mut/Mb (median 2.5 mut/Mb). MSI was found in 3 pts (1.5%). 196 pts (47.1%) had an OncoKB LE 1 alteration, 105 pts (25.6%) if we restrict the options to their specific cancer type. 16 pts (3.9%) received a matched therapy: 6 pts received an off-label drug, 6 pts were included in the same CT for which the pre-screening was performed and 4 pts were included in a different CT. Additionally, 13 pts (3.2%) received a matched therapy either with OncoKB LE 4 (5 pts received an off-label drug and 3 were included in a different CT) or not included in OncoKB (8 pts included in the same CT of the pre-screening). As a whole, 29 pts (7.1%) received a matched drug according to their genomic results. Conclusions: Comprehensive gene panel testing offered through CT allows the identification of targets to enroll pts, although the recruitment was 1.5%. However, 7.1% of the pts received a matched therapy due to the molecular information of these gene panels.

CANTATA: Primary analysis of a global, randomized, placebo (Pbo)-controlled, double-blind trial of telaglenastat (CB-839) + cabozantinib versus Pbo + cabozantinib in advanced/metastatic renal cell carcinoma (mRCC) patients (pts) who progressed on immune checkpoint inhibitor (ICI) or anti-angiogenic therapies

4501

Background: Dysregulated metabolism is a hallmark of RCC, driven by overexpression of glutaminase (GLS), a key enzyme of glutamine metabolism. Telaglenastat (Tela) is an investigational, first-in-class, selective, oral GLS inhibitor that blocks glutamine utilization and critical downstream pathways. Preclinically, Tela synergized w/ cabozantinib (Cabo), a VEGFR2/MET/AXL inhibitor, against RCC tumors. In a Ph 1 study cohort, Tela+Cabo showed encouraging safety/efficacy as 2L+ therapy for mRCC. This trial compared Tela+Cabo vs Pbo+Cabo in previously treated pts w/ clear-cell mRCC (NCT03428217). Methods: Eligible pts had 1-2 prior lines of systemic therapy for mRCC, including ≥1 anti-angiogenic therapy or nivolumab + ipilimumab (nivo/ipi), KPS ≥70%, measurable disease (RECIST 1.1), no prior Cabo or other MET inhibitor. Pts were randomized 1:1 to receive Cabo (60 mg PO QD) with either Tela (800 mg PO BID) or Pbo, until disease progression/unacceptable toxicity, and were stratified by prior PD-(L)1 inhibitor therapy (Y/N) and IMDC prognostic risk group. Primary endpoint was progression-free survival (PFS; RECIST 1.1) by blinded independent radiology review. The study was designed to detect a PFS hazard ratio (HR) of 0.69 w/ alpha 0.05 and 85% power. Data cutoff date: August 31, 2020. Results: 444 pts were randomized (221 Tela+Cabo; 223 Pbo+Cabo). Baseline characteristics were balanced between arms. Median follow-up was 11.7 mo; 276 pts received prior ICI, including 128 w/ prior nivo/ipi. Median PFS (mPFS) was 9.2 mo for Tela+Cabo vs 9.3 mo for Pbo+Cabo (HR = 0.94; 95% CI: 0.74, 1.21; stratified log-rank P= 0.65) with overall response rates (ORR; confirmed) of 31% with Tela+Cabo vs 28% Pbo+Cabo, respectively. Overall survival was not mature at data cutoff. In a prespecified subgroup analysis in pts w/ prior ICI, mPFS was numerically longer w/ Tela+Cabo than Pbo+Cabo (11.1 vs 9.2 mo, respectively; unstratified HR = 0.77; 95% CI: 0.56, 1.06). In the Pbo+Cabo arm, mPFS was 9.2 mo for pts w/ prior ICI exposure and 9.5 mo for pts without, and ORR was 32% and 20%, respectively; if ICI included nivo/ipi, ORR was 37%. Rates of adverse events (AEs) were similar between arms.Grade 3-4 AEs occurred in 71% of Tela+Cabo pts and 79% of Pbo+Cabo pts and included hypertension (17% vs 18%) and diarrhea (15% vs 13%). Cabo was discontinued due to AEs in 10% of Tela+Cabo pts and 15% of Pbo+Cabo pts. Conclusions: The addition of Tela did not improve the efficacy of Cabo in mRCC in this study. Tela+Cabo was well tolerated with AEs consistent with known risks of both agents. The study provides valuable insight on efficacy outcomes of a contemporary population of pts w/ mRCC who receive Cabo in the 2/3L setting. Clinical trial information: NCT03428217.

Randomized phase Ib study to evaluate safety, pharmacokinetics and therapeutic activity of simlukafusp α in combination with atezolizumab ± bevacizumab in patients with unresectable advanced/ metastatic renal cell carcinoma (RCC) (NCT03063762)

4556

Background: Simlukafusp α ([SIM], FAP-IL2v) is a novel IL-2v immunocytokine engineered to preferentially activate effector CD8 T and NK cells, but not regulatory T cells (Tregs), due to abolished binding to Interleukin-2 receptor α (IL-2Rα) and retained affinity to IL-2Rβγ. High affinity binding of SIM to fibroblast activation protein (FAP), expressed on cancer-associated fibroblasts, mediates its accumulation in malignant lesions. Methods: The Dose-Escalation (DE) consisted of: Arm A: SIM 5-25 mg weekly for 4 weeks, and every 2 weeks (Q2W) thereafter in combination with atezolizumab [ATZ] 840mg Q2W; and Arm B: same as Arm A + bevacizumab [BEV] 10 mg/kg Q2W. Patients (pts) not previously treated were evaluated in the Extension Part: Arm C (n=3): SIM + ATZ every 3 weeks (Q3W); or Arm D (n=25): SIM + ATZ + BEV (“triplet”) Q3W. Primary objectives were: finding the recommended dose of SIM and assessment of objective response rate (ORR) by RECIST v1.1. Results: We enrolled 69 pts with unresectable advanced/ metastatic clear-cell and/or sarcomatoid RCC. Median age of patients was 57 years (range: 35-78). The recommended dose for extension of SIM was 10 mg. Median treatment duration in days in each arm were: A: 106 (range: 1-877); B: 324 (8-940); C: 659 (71-768); D: 437 (1-682). Twenty-five pts are evaluable for therapeutic activity in Arm A [ORR: 24% (6 PR; 90% CI 12.95, 40.12)]; 15 in Arm B [46.7% (1 CR, 6PR; 90% CI 27.67, 66.68)]; 3 in Arm C [33.3% (1PR; 90% CI 7.83, 74.65)]; and 23 in Arm D [47.8% (2 CR, 9 PR; 90% CI 35.74, 68.15)]. Twelve patients are ongoing on study treatment. Treatment related grade 3 and 4 adverse events (AE) occurred respectively in 69.7% and 9.1% patients. The most common serious AEs were pyrexia (10.6 %) and infusion-related reactions (9.1%). 65.2% Of the patients reported at least one AE of elevations in liver transaminases/GGT/ alkaline phosphatase/bilirubin. Drug-related AEs led to dose modification/interruption in 37.9 % of the pts, and treatment discontinuation in 3% of the patients. SIM led to preferential expansion and activation of NK and CD8 T cells (but not Tregs) in peripheral blood and augmented tumor infiltration and tumor inflammation. Intriguingly responses were observed not only in pts with PD-L1 positive or inflamed tumors, but also in pts with PD-L1 negative tumors (n=13) or poorly infiltrated tumors classified as immune deserts (n=2). Conclusions: The combination of SIM with ATZ ± BEV was feasible with an acceptable safety profile. Clinical activity was more favorable for the triplet among the study Arms, but comparable to the ATZ + BEV combination in the IMmotion151 (Rini B, et al 2019). Observed pharmacodynamic findings were consistent with the expected effects. Clinical trial information: NCT03063762.

Management of fibroblast growth factor receptor inhibitor (FGFRi) treatment-emergent adverse events (TEAEs) of interest in patients (Pts) with locally advanced or metastatic urothelial carcinoma (mUC)

426

Background: Erdafitinib (ERDA), a pan-FGFR kinase inhibitor, was US FDA approved for adults with mUC with susceptible FGFR3/2 alterations ( FGFRa) who progressed on ≥ 1 line of prior platinum-based chemotherapy based on primary results of the BLC2001 trial (NCT02365597). At final analysis (median 2-y follow-up), ERDA showed median OS of 11.3 mo and a manageable safety profile. Some FGFRi toxicities are distinct from those of other small-molecule TKIs. Proactive AE management can avoid treatment discontinuation, ensuring maximum benefit. We report the frequency and management of TEAEs of interest (central serous retinopathy [CSR], hyperphosphatemia [“on-target” FGFRi class effect], stomatitis, and skin and nail toxicities) for the optimal schedule of ERDA from the final analysis of BLC2001. Methods: The open-label, phase II BLC2001 study enrolled pts with measurable mUC, prespecified FGFRa, and progression during/after ≥ 1 line of prior chemotherapy or ≤ 12 mos of (neo)adjuvant chemotherapy or who were cisplatin ineligible, chemo naive. Optimal dose schedule in the study was 8 mg/d continuous ERDA in 28-d cycles with uptitration to 9 mg/d (ERDA 8 mg/d UpT) if prespecified serum phosphate level was not reached and no significant TEAEs occurred. ERDA 8 mg/d UpT safety results as of Aug 9, 2019 (final analysis) are summarized here. AEs were graded using NCI CTCAE v4.0. Results: Median follow-up for 101 pts treated with ERDA 8 mg/d UpT was 24.0 mos; median treatment duration was 5.4 mos. All pts had ≥ 1 TEAE. Hyperphosphatemia, stomatitis, nail disorders, skin disorders, and CSR TEAEs occurred in 78%, 59%, 59%, 55%, and 27% of pts, respectively (few were grade [gr] 3; none were gr ≥ 4; Table). TEAEs were mostly managed with concomitant treatment and dose modifications. As of data cutoff, hyperphosphatemia had resolved in 74/79 (94%) pts; stomatitis in 44/60 (73%); nail and skin TEAEs in 26/60 (43%) and 25/55 (45%), respectively; and CSR in 17/27 (63%). Most unresolved TEAEs were gr 1–2. No treatment-related deaths occurred. Conclusions: ERDA had measurable benefit in pts with advanced UC with FGFRa. As with other targeted therapies, exposure to ERDA is associated with a pattern of AEs. The most common and FGFRi class effect TEAEs were generally reversible and managed by supportive care and dose modification. Clinical trial information: NCT02365597 . Research Sponsor: Janssen Research & Development, LLC[Table: see text]

A phase I study of capivasertib in combination with abiraterone acetate in patients with metastatic castration-resistant prostate cancer

85

Background: Androgen receptor (AR) targeting therapies prolong survival of patients with metastatic castration-resistant prostate cancer (mCRPC); however, in many cases, resistance develops, resulting in disease progression. Activation of the PI3K/AKT/mTOR signaling pathway is common in mCRPC and contributes to resistance, mostly due to loss of PTEN, which occurs in 40–60% of patients. Preclinical studies have demonstrated reciprocal regulation between the AR and PI3K/AKT/mTOR pathways and significant anti-tumor activity when both pathways are inhibited, particularly in models with PTEN-loss. Thus, a rationale exists to inhibit both pathways in mCRPC patients. We report interim results of a phase 1 multicohort study (NCT04087174) to confirm the acceptable dose of capivasertib, a potent, selective pan-AKT inhibitor in combination with the androgen synthesis inhibitor abiraterone acetate (AA) in mCRPC patients. Methods: Patients who had received at least one prior systemic therapy (chemotherapy or novel hormonal agent) for mCRPC were given AA (1000 mg, once daily) with capivasertib (400 mg, twice daily, 4 days on/3 days off) until unacceptable toxicity or disease progression. Dose-limiting toxicity in the first 28 days of treatment and adverse events were recorded. Results: 15 patients, median age 67 (range 49–82) years, were recruited in the USA and Spain. Twelve patients had received prior chemotherapy; 7 had two or more prior lines. Seven patients had received prior AA and 10 had received prior enzalutamide. No dose-limiting toxicities were recorded. Eight patients reported at least one grade ≥ 3 adverse event (AE). Grade ≥ 3 AEs in 7 patients were related to capivasertib: allergic reaction to medication, asthenia, type 2 diabetes mellitus, diarrhea and fatigue were each reported in 1 patient, maculopapular rash − in 2 patients, both hypokalemia and acquired Fanconi syndrome − in 1 patient. Acute kidney injury was reported in 4 patients but was not considered related to capivasertib. The most common AEs of any grade related to capivasertib were: diarrhea, 6/15 patients (40%); maculopapular rash, 5/15 (33%); fatigue, 4/15 (27%); hyperglycemia/type 2 diabetes mellitus, 4/15 (27%); nausea, 3/15 (20%); hypokalemia, 2/15 (13%); hypophosphatemia, 2/15 (13%). Capivasertib was discontinued in 4/15 patients (27%) due to AEs. Between initial screening and day 29 of treatment, 5 patients had reduced (> 20%) PSA levels, with 3 patients showing sustained falls in PSA over 12 weeks. Conclusions: In this phase 1 study combined capivasertib and AA exhibits an acceptable safety and tolerability profile. Further data on the clinical efficacy and safety of the combination are being collected in the phase 3 CAPItello-281 trial. Acknowledgments: We thank Adam Errington, PhD, of Oxford PharmaGenesis, for medical writing assistance. Funding: This trial is funded by AstraZeneca. Clinical trial information: NCT04087174.

Diagnostic utility and therapeutic impact of PET/CT [18F]F-Fluoromethylcholine -Choline in the biochemical recurrence of prostate cancer

OBJECTIVE

To assess the diagnostic capability of PET/CT with [¹⁸F]F-Fluoromethylcholine in prostate cancer (PC) with biochemical recurrence and its therapeutic impact.

MATERIAL AND METHODS

We included 108 patients, diagnosed with PC with biochemical criteria for recurrence. A PET/CT Choline scan was performed by dynamic pelvic and whole body study at 60min post-tracer injection. The relationship between the positive studies and the PSA value was analysed by classifying patients into three groups (<1.2/1.2-2/>2ng/ml), and the diagnostic capacity was assessed with respect to pelvic MRI and the impact on the therapeutic decision.

RESULTS

The location of recurrence was identified in 85 of 108 patients (78.7%): 34 local, 47 pelvic lymph nodes and 58 distant lesions, including retroperitoneal, mediastinal lymph nodes and distant organ lesions (bone and lung). Second tumors were diagnosed in 4 patients. No significant differences were found in the percentage of positive studies depending on primary treatment. Patients with PSA>2ng/ml showed a higher percentage of disease detection than patients with a lower PSA level, with significant differences (p<0.0001). PET/CT [¹⁸F]F-Choline was able to detect local disease, not previously known from MRI, in 29.41% of patients. PET/CT Choline had an impact on therapeutic management in 67 of 108 patients (62%).

CONCLUSIONS

PET/CT with [¹⁸F]F-Fluoromethylcholine is a useful tool in the detection of locoregional and disseminated disease of PC treated with suspicion of recurrence, providing a change in therapeutic management in 62% of patients.

Evolving development of PD-1 therapy: Cetrelimab (JNJ-63723283) from monotherapy to combination with erdafitinib

3055

Background: Cetrelimab (CET) is an investigational checkpoint inhibitor (CI). In part 1 of a first-in-human (FIH) trial (LUC1001; NCT02908906), pts with advanced solid tumors with ≥1 prior treatment received CET 80–800 mg Q2W or 480 mg Q4W. Response rates and safety profiles were similar to other CIs. Based on preclinical and clinical data, a phase 1/2 study (NORSE; NCT03473743) of CET + erdafitinib (ERD) in metastatic urothelial carcinoma (mUC) + FGFR alterations (alt) was initiated and is ongoing. Methods: In LUC1001 Part 2, pts with nonsmall cell lung cancer (NSCLC), melanoma (MEL), or MSI-H/dMMR colorectal cancer (CRC) received CET IV 240 q2w. Overall response rates (ORR = % complete response + partial response [PR] confirmed) were assessed as per RECIST v1.1. Adverse events (AEs) were assessed for all patients receiving CET IV 240 q2w in parts 1 and 2. Results: As of July 1, 2019, 122 pts with NSCLC (n=30); MEL (n=50); or CRC (n= 42) had been treated in Part 2. Median age ranged from 58 to 64 yrs (overall range, 23–86 yrs). Duration of treatment was 8.1 mos (range, 0.0-24.7) for NSCLC; 5.5 mos (range, 0.0-25.0) for MEL; and for 3.0 mos (0.0-16.1) for CRC. ORR was 37% in NSCLC; 53% in PD-L1+ NSCLC (≥50% by IHC), 28% in MEL; 32% in non-uveal MEL, 14% in CRC and 24% in centrally confirmed MSI-high CRC. In all CET IV 240 q2w treated pts in the FIH study (N= 162), treatment-related grade ≥3 and serious AEs were reported in 15% and 12% of pts, respectively. All grade and grade ≥3 immune-related (ir) AEs were reported in 41% and 8% of pts, respectively Most common ir AE: hypothyroidism (8%), asthenia (6%), diarrhea (4%), rash (4%), hyperthyroidism (4%), dyspnea (3%), pruritis (3%) and pneumonitis (3%). There was 1 treatment-related death due to myasthenia gravis. In the phase 1 combination study (NORSE), pts with mUC + FGFR alt (n=17) received fixed-dose CET IV 240 q2w + ERD 6mg, 8 mg or 8mg + up titration (UpT) to 9 mg to establish the RP2D for the combination as CET + ERD 8mg + UpT. In the RP2D group (n=10), 60% had treatment-related grade ≥3 AEs. ORR (all confirmed PR) was 50% in the all treated response-evaluable group (n=16). Conclusions: CET is a CI with efficacy and safety profiles in advanced solid tumors similar to approved CIs. In NORSE phase 1, CET+ ERD demonstrated antitumor activity in mUC with an acceptable safety profile. NORSE phase 2 is evaluating this combination as first-line therapy in pts with mUC with FGFR alt. References: Rutkowski, et al J Clin Oncol.2019; 37 (8 suppl): 31-31. Moreno, et al. ASCO-GU Genitourinary Cancers Symposium. February 13-15, 2020. San Francisco, CA. Clinical trial information: NCT02908906 and NCT03473743 .

ERDAFITINIB in locally advanced or metastatic urothelial carcinoma (mUC): Long-term outcomes in BLC2001

5015

Background: Erdafitinib (JNJ-42756493; ERDA) is the only pan-FGFR kinase inhibitor with US FDA approval for treatment of adults with mUC with susceptible FGFR3/2 alterations (alt) and who progressed on ≥ 1 line of prior platinum-based chemotherapy (chemo). Approval was based on data from the primary analysis of the pivotal BLC2001 trial1. Here we report long-term efficacy and safety data from the 8 mg/d continuous dose regimen in BLC2001. Methods: BLC2001 (NCT02365597) is a global, open-label, phase 2 trial of pts with measurable mUC with prespecified FGFR alt, ECOG 0-2, and progression during/following ≥ 1 line of prior chemo or ≤ 12 mos of (neo)adjuvant chemo, or were cisplatin ineligible, chemo naïve. The optimal schedule of ERDA determined in the initial part of the study was 8 mg/d continuous ERDA in 28-d cycles with uptitration to 9 mg/d (ERD 8 mg UpT) if a protocol-defined target serum phosphate level was not reached and if no significant treatment-related adverse events (TRAEs) occurred. Primary end point was the confirmed objective response rate (ORR=% complete response + % partial response). Key secondary end points were progression-free survival (PFS), duration of response (DOR) and overall survival (OS). Results: Median follow-up for 101 patients treated with ERDA 8 mg UpT was ~24 months. Confirmed ORR was 40%. Median DOR was 5.98 mos; 31% of responders had DOR ≥ 1 yr. Median PFS was 5.52 mos, median OS was 11.3 mos. 12-mos and 24-mos survival rates were 49% and 31%, respectively. Median treatment duration was 5.4 mos. The ERDA safety profile was consistent with the primary analysis. No new TRAEs were seen with longer follow-up. Central serous retinopathy (CSR) events occurred in 27% (27/101) of patients; 85% (23/27) were Grade 1 or 2; dosage was reduced in 13 pts, interrupted for 8, and discontinued for 3. On the data cut-off date, 63% (17/27) had resolved; 60% (6/10) of ongoing CSR events were Grade 1. There were no treatment-related deaths. Conclusions: With a median follow-up of 2 yrs, ERDA in mUC + FGFR alt showed a manageable safety profile and consistent efficacy, with median OS of 11.3 mos. 31% had a DOR ≥12 mos and 31% were alive at 24 mos. ERDA monotherapy vs. immune checkpoint inhibitor (PD-1) or chemo is being further analyzed in a randomized control study (THOR; NCT03390504).Reference: Loriot Y, et al. N Engl J Med. 2019;381:338-48. Clinical trial information: NCT02365597 .

Use of plasma androgen receptor (AR) testing to optimize docetaxel chemotherapy in castration-resistant prostate cancer (CRPC): A multicenter biomarker study

5546

Background: Plasma AR status has been identified as a potential biomarker of response in CRPC patients receiving docetaxel or the AR-targeted therapies abiraterone or enzalutamide. However, the relevance of plasma AR in the overall management of CRPC patients (pts) receiving docetaxel at different dose due to the toxicity profiles and physician-patient preferences is unknown. Methods: This was a multi-institution study of associations between baseline plasma AR-copy-number status assessed by droplet digital PCR and outcome in 325 CRPC pts. Between September 2011 and July 2019 pts started treatment with docetaxel administered at standard regimen 75mg/m2 every three weeks or adapted regimen (75-80% of standard recommended dose or 30mg/m2 weekly administration) at the discretion of the treating physician. Patients were assigned randomly into 2 sets with a ratio 2:1 to either training (n=217) and internal validation (n=108) cohorts. Results: In our study, adapted regimen of docetaxel was administered in 68 (31.3%) and 35 (32.4%) of training and validation cohorts, respectively. Based on plasma AR status, 67 (30.9%) and 39 (36.1%) validation and training set pts were classified as AR gain, respectively. In men treated with standard docetaxel regimen, no difference in progression-free/overall survival (PFS/OS) was seen between plasma AR normal and gain in both cohorts. In patients treated with adapted docetaxel regimen, we observed a significantly shorter median PFS (3.9 vs. 6.4 months, HR 4.77, 95%CI 1.48-3.80, p=0.0003) and median OS (11.2 vs . 20.4 months, HR 2.87, 95%CI 1.73-2.13, p=0.0008) in the training cohort. This finding was confirmed in the validation cohort (median PFS: 4.8 vs. 7.4 months, HR 2.54, 95%CI 1.40-4.58, p=0.005, and median OS: 11.8 vs. 26.4 months, HR 5.00, 95%CI 2.59-9.65, p<0.0001). In addition, AR-gained patients were less likely than AR normal to have a PSA decline when receiving an adapted regimen in both cohorts (p=0.010 e p=0.003, respectively). Conclusions: This study suggests that plasma AR may improve clinical decision making in choosing not only between AR-directed therapies and taxanes, but also between adapted and standard regimen of docetaxel in first- and subsequent-therapy lines, providing promising clinical implications to select the proper timing and dose of docetaxel. Prospective trials to validate these findings are warranted.

Single nucleotide polymorphisms (SNPs) as predictors of efficacy of cabazitaxel in patients with metastatic castration-resistant prostate cancer (mCRPC)

e17582

Background: Cabazitaxel is a semi-synthetic derivative of a natural taxoid approved for the treatment of mCRPC patients (pts) after failure to docetaxel. Despite its proven efficacy, there is variability in the response, progression-free survival (PFS) and overall survival (OS) of pts. Changes in the genetic constitution of the individual such as the SNPs could explain this variability. The aim of this study was to evaluate the impact of certain SNPs in cabazitaxel activity. Methods: Clinical data from 67 mCRPC pts treated with cabazitaxel between March 2011 and October 2016 were collected. DNA was isolated from formalin fixed paraffin-embedded tumor samples. 56 SNPs in 5 genes related with metabolism and/or mechanism of action of cabazitaxel (CYP3A4, CYP3A5, ABCB1, TUBB1, CYP2C8) were chosen based on their Minor Allele Frequency, linkage disequilibrium and information from dbSNP and analyzed by TaqMan OpenArray (Lifetech). The presence/absence of mutant alleles of the selected SNPs was correlated with clinical features, progression free survival (PFS) and overall survival (OS) of prostate cancer. Chi-square test and Kaplan-Meier with log-rank test were used for statistical analyses. Results: The median age was 61 years (range 44-82). 56.7% (n = 38) had a Gleason score ≥8 and 94% had received docetaxel in first line. Type of response to cabazitaxel was associated with median OS (Partial response = 24.35 months, Stable disease = 11.16 months, Progression disease = 5.8 months; p= 0.045). Univariate analysis, showed worsed OS at 1 year for wild type status of SNP rs151352 (OR = 4, 95%CI 1.27-12.58, p= 0.029). In addition, two SNPs (rs11773597, rs1202186) were associated with radiological response to cabazitaxel ( p= 0.031 and p= 0.030 respectively). Other 7 SNPs (rs11773597, rs2235040, rs1045642, rs1419745, rs1202170, rs6949448, rs11572093) were associated ( p<0.05) with Gleason score, pain, PSA doubling time, febrile neutropenia and asthenia. Conclusions: A particular SNP profile could be predictive of efficacy and related with toxicity in mCRPC population treated with cabazitaxel after progression to docetaxel. These outcomes become particularly relevant in patient selection given the recent results of the CARD trial.

A randomized phase II study of nivolumab plus ipilimumab versus standard of care in previously untreated and advanced non-clear cell renal cell carcinoma (SUNIFORECAST)

TPS5103

Background: Non-clear cell renal cell carcinomas (nccRCC) are a heterogeneous group of tumors accounting for approximately 25% of RCC patients (pts.). Since most clinical trials focus on clear-cell RCC (ccRCC) only, data on treatment strategies for nccRCC are limited. The combination of Nivolumab and Ipilimumab (IO/IO) has recently been approved for treatment in RCC showing a significant improvement in overall response rate (ORR), progression free (PFS), and overall survival (OS) in intermediate and high-risk pts. compared to sunitinib in a phase-III trial. Furthermore retrospective analysis in nccRCC patients have shown promising results for IO/IO as well in these entities. Methods: In this prospective randomized phase-II multicenter European trial adults with advanced or metastatic nccRCC without prior systemic therapy are eligible. Other key inclusion criteria include: available tumor tissue, Karnofsky > 70% and measurable disease per RECIST 1.1. All histological diagnoses are reviewed by a central pathologist. The study plans to randomize ~306 pts. stratified for papillary or non-papillary non-clear cell histology and by the International Metastatic RCC Database Consortium (IMDC) risk score. Pts. will be randomized 1:1 to either i) Nivolumab 3mg/kg intravenously (IV) plus Ipilimumab 1mg/kg IV every 3 weeks for 4 doses followed by Nivolumab fixed dose 240mg IV every 2 weeks or ii) standard of care therapy according to the approved schedule. Treatment will be discontinued in case of unacceptable toxicity or withdrawal of informed consent. Pts may continue treatment beyond progression, if clinical benefit is achieved and treatment is well tolerated. Primary endpoint is the OS rate at 12 months. Secondary endpoints include OS rate at 6 and 18 months, median OS, PFS, ORR and quality of life. The trial is in progress and 122 patients (78 pts with papillary, 37 pts with non-papillary histology) have been enrolled until now. Clinical trial information: NCT03075423 .

Atezolizumab (atezo) therapy for locally advanced/metastatic urinary tract carcinoma (mUTC) in patients (pts) with poor performance status (PS): Analysis of the prospective global SAUL study

5035

Background: Pts with PS > 1 have a poor prognosis and are often excluded from clinical trials. The single-arm SAUL study (NCT02928406) evaluated atezo in a ‘real-world’ population. Overall, safety and efficacy were consistent with prior trials. However, ECOG PS 2 pts had worse overall survival (OS) but fewer adverse events (AEs) than ECOG PS 0/1 pts [Sternberg, 2019], likely reflecting shorter treatment duration and warranting exploration. Methods: Pts with mUTC received atezo 1200 mg q3w until loss of clinical benefit or unacceptable toxicity. The primary endpoint was safety. Post hoc analyses compared baseline factors, AEs and efficacy in pts with ECOG PS 2 vs 0/1. In this analysis, AE incidences were restricted to the first 45 days of atezo to adjust for differing treatment exposure. Results: None of the baseline factors explored was significantly associated with worse OS or disease control rate (DCR) in ECOG PS 2 pts. However, pts with visceral metastases and ECOG PS 2 had particularly poor outcomes. Safety appeared similar between subgroups. Conclusions: ECOG PS 2 pts have a dismal prognosis. The higher proportion with poor prognostic factors despite similar age in ECOG PS 2 vs 0/1 pts may suggest that poor PS was related to disease rather than comorbidities. Risk/benefit should be considered especially carefully when treating pts with ECOG PS 2 due to high-burden/visceral disease. Clinical trial information: NCT02928406 . [Table: see text]

Does escalation results from phase Ib/II Norse study of erdafitinib (ERDA) + PD-1 inhibitor JNJ-63723283 (Cetrelimab [CET]) in patients (pts) with metastatic or locally advanced urothelial carcinoma (mUC) and selected fibroblast growth factor receptor (FGFR) gene alterations

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Background: ERDA, an oral pan-FGFR inhibitor, is approved by the US FDA for pts with metastatic urothelial carcinoma (mUC) with susceptible FGFR3/2 gene alterations and progressed after ≥1 line of prior platinum-containing chemotherapy (PCC).1 CET, an IgG4, binds to anti-programmed cell death proteins (PD-1) and has shown activity in solid tumors.2 ERDA+CET may demonstrate complementary mechanisms as neoantigen release by ERDA may prime the tumor microenvironment for response. NORSE is a phase 1b/2 study to evaluate ERDA+CET in pts with mUC. Methods: Adult mUC pts with specific FGFR alterations who have progressed after ≥1 prior systemic therapy and no prior FGFR or PD-1/PD(L)-1 inhibitors enrolled in 3 dose levels (DL) of ERDA (DL1: 6 mg, DL2A: 8 mg, DL2: 8 mg with uptitration [UPT] to 9 mg) + CET (IV, 240 mg). Cohorts enrolled until dose limiting toxicity (DLT) or RP2D was identified. Primary endpoints: DLT and adverse events (AEs). Results: Of 15 pts (DL1: 4, DL2A: 3, DL2: 8), 11 continued on treatment at the time of the data cut. 14/15 pts experienced AEs; 3 experienced serious unrelated AEs (urinary tract infection, urosepsis, and large intestinal obstruction) all in DL1, 2 led to death; 10 experienced Grade >3 AEs and 2 experienced AEs of special interest, considered related to ERDA (Table). No DLTs were observed in any cohorts, 8 mg with UPT + CET was established as the RP2D. At data cut-off, investigator-assessed best overall response rate (CR+PR+uCR+uPR) in pts treated with the RP2D was 71% and disease control rate was 100% for RECIST 1.1 evaluable pts (n=7). Conclusions: 8 mg ERDA with UPT+240 mg CET was well tolerated and established as the RP2D. The combination of ERDA+CET is being further explored in the ongoing randomized phase 2 study in first-line cisplatin-ineligible mUC pts (NCT03473743). Clinical trial information: 2017-001980-19. [Table: see text]

Association of neuroendocrine (NE) mRNA expression profiling in hormone-sensitive tumors samples with adverse clinical outcome in castration-resistant prostate cancer (CRPC) patients

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Background: NE dedifferentiation is associated to clinical aggressiveness and resistance to androgen receptor inhibition in prostate cancer. We investigated impact of a NE expression signature in the clinical outcome of mCRPC patients treated with taxanes. Methods: This is a multicenter retrospective study. A customized panel of 45 NE-related gene signature was tested in total RNA from formalin-fixed paraffin-embedded hormone-sensitive tumor samples, by the nCounter platform (Nanostring Technologies). Patients were grouped according to their molecular profile by unsupervised clustering. Expression levels were correlated with taxanes response and clinical outcome. Independent association with survival was evaluated by multivariate Cox modeling. Results: Eighty seven patients were included in the study, 79 were treated with docetaxel and 8 with cabazitaxel. Median age was 64.8 (44-88.3) years and median follow-up was 20.7 (1.17-74.4) months. High expression of the NE signature was associated with a shorter time of CRPC development (N=60, median 12.8 vs 21.6, HR 2.4, 95%CI 1.3-4.3, P=0.003) and shorter OS from CRPC diagnosis (median 24.1 vs 41.33, HR 2.3, 95%CI 1.4-3.8, P=0.001). Moreover, according to the outcome to taxanes, high NE signature correlated with lower PSA-PFS (median 6.6 vs 10.1 mo P=0.047, HR 1.6, 95%CI 1-2.7, P=0.05) and OS (median 19 vs 22 mo, HR 1.8, 95%CI 1.1-2.8, P=0.014), and it was independently associated to a lower OS (HR 1.9, 95%CI 1.1-3.2, P=0.016). Conclusions: NE-related gene expression in hormone-sensitive tumor samples is associated with adverse clinical outcome and lower taxane benefit in metastatic CRPC patients. Thus, molecular characterization of primary tumors may be useful to guide treatment strategies in metastatic prostate cancer.

Randomized phase II study of docetaxel (D) + abiraterone acetate (AA) versus D after disease progression to first-line AA in metastatic castration-resistant prostate cancer (mCRPC): ABIDO-SOGUG Trial

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Background: Abiraterone acetate (AA) improves OS and rPFS in first line mCRPC patients (pts). After AA progression D is commonly used as standard second line therapy. However, the value of maintaining AA in combination with D despite progression has not been tested beyond small exploratory studies (Tagawa ST, Eur Urol 2016) ABIDO is a randomized-phase II trial that evaluates efficacy and safety of D + AA vs D after first-line AA progression in mCRPC. Methods: Asymptomatic or minimally symptomatic mCRPC pts with no visceral metastases, ECOG PS 0-1, and adequate organ functions were included. The study has two stages: In stage I pts receive AA (1000 mg/d + prednisone (P) 10 mg qd) until radiological or unequivocal clinical progression. In stage II pts were randomized to D 75 mg/m2 q3wk in combination with AA 1000 mg/d (arm A) or without AA (arm B) The primary endpoint was rPFS and the secondary endpoints radiological response (RR), OS, PSA-response, PSA-PFS and safety. Results: 88 pts were randomized, (46 arm A, 42 Arm B). Median age was 69 y/o, 43% had ECOG 0 and 91%/11%/5% had bone, liver and lung metastases. Median rPFS was 11.4 months (m) in arm A vs 10.5 m in ARM B; 12-m rPFS was 43% vs 45%; Median PSA PFS was 6.2 vs 5.5 m and median OS was 17.3 vs 16.9 m. Twenty four pts (52%) in arm A and 19 (46%) in arm B achieve ≥50% PSA response. RR was achieved in 15% vs 7% of pts and disease control rate in 74% in both arms. No statistically significant differences were found in efficacy parameters. Half of pts received 10 cycles of D (median 7 and 8). D median dose intensity was 86% and 90% for each arm and 91% for AA. Eleven pts discontinued treatment due to non-hematological toxicity, 5 in arm A and 6 in arm B. Most frequent G3-4 toxicities per arm (A/B) were: neutropenia (57%/29%; P=0.027), febrile neutropenia (17%/10%), diarrhea (9%/7%), and asthenia (11%/10%). Conclusions: ABIDO trial was unable to demonstrate the significant clinical benefit of maintenance AA approach + D after AA first-line therapy. No differences were observed in RR, PSA PFS, rPFS and OS. In AA + D cohort, more frequent and severe hematological toxicity (neutropenia and febrile neutropenia) were reported. Clinical trial information: NCT02036060.

Association of high plasma glutamine levels with outcome in metastatic castration-resistant prostate (mCRPC) patients treated with taxanes

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Background: Cancer cells may metabolize glutamine to fulfill their metabolic needs. In prostate cancer it has been shown that androgen receptor signaling promotes glutamine metabolism by increasing the expression of the glutamine transporters, and that stromal glutamine may promote tumor growth. Methods: We retrospectively tested glutamine levels in frozen plasma samples from mCRPC patients treated with taxanes, which were included in a prospective biomarker study in our institution. Glutamine levels were determined by a bioluminescent assay. Optimal cut-offs for glutamine levels were assessed using maximally selected log-rank statistics to determine low and high level groups. Pre-treatment glutamine level was correlated with taxanes response and clinical outcome. Independent association with survival was evaluated by multivariate Cox modeling. Results: Seventy eight mCRPC patients treated with taxanes were included. Median age was 70.3 (55.8-83.5) years and median follow-up was 13.1 (0.2-53.9) months. Glutamine was tested in 88 plasma samples: 69 from pre-docetaxel and 19 pre-cabazitaxel treatment (10 patients had both samples). High glutamine levels significantly correlated with worst PSA-progression-free survival (PFS) (median 2.8 vs 4.7 months, hazard ratio [HR] 1.8, 95%CI 1.1-2.7, P= 0.012) and overall survival (OS) (median 12.4 vs 20.4, HR 2, 95%CI 1.2-3.3, P= 0.006). In a multivariate analysis, high plasma glutamine levels were independently associated with shorter PSA-PFS (HR 2.3, 95%CI 1.4-3.7, P< 0.001) and OS (HR 2.2, 95%CI 1.3-3.7, P= 0.003). Patients with high glutamine levels were more likely to present PSA progression to taxanes than those with low levels (odds ratio [OR] 3, 95%CI 1.2-7.7, P= 0.016). Moreover, samples from patients treated with abiraterone or enzalutamide before taxanes (51 samples from 43 patients) had significantly higher glutamine levels (T-test, P= 0.014) than those without these prior therapies. Conclusions: Glutamine can be detected in plasma of mCRPC patients and higher levels are associated with adverse clinical outcome, supporting the relevance of metabolism in prostate cancer progression.

Response to immunotherapy, platinum-based chemotherapy or their combination in metastatic urothelial carcinoma (MUC) with or without FGFR-3 alterations: Single cohort experience

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Background: Fibroblast growth factor receptor-3 (FGFR-3) is a promising target therapy in metastatic urothelial carcinoma. Its role in patient’s clinical outcome and treatment response is unclear. We present data for overall survival (OS) and response to platinum-based treatment, immunotherapy and combination (platinum plus immunotherapy) in MUC. Methods: Enrolled patients were diagnosed with muscle-invasive urothelial cancer (MIUC) between 2/2009-6/2019 at Clinic Hospital of Barcelona, Spain. All have been screened for FGFR-3 alterations using next-generation sequencing or qualitative real-time polymerase chain reaction-based assays in tumour or blood. Demographic, pathology, treatments and treatment response were collected retrospectively. Results: 101 patients with MIUC were screened, 99% had progressed to metastatic stage. At diagnosis 32.67% were metastatic. 77% were man and median age was 68y (38-85y). Median follow-up (FU) since metastatic disease was 16.25 months (1.2-89.72m) with 69.31% of patients had died at cut-off. 32% presented FGFR-3 alteration (fusion =1 and mutation=31). FGFR-3 altered more frequently had papillary histology than FGFR-3 wild type tumours (69 vs 26%, p<0.05). No statistical differences were detected between both groups for gender, age, stage at diagnosis, median FU, primary tumour site (upper vs lower tract) or previous history of non-invasive urothelial carcinoma. 58% patients received 1st line platinum-based chemotherapy, 25% immunotherapy and 8% the combination of both (9% with other therapies). FGFR-3 altered tended to present more benefit (complete, partial response or stable disease) with platinum-based chemotherapy than FGFR-3 wild type (81% vs 62%) but without reach statistical significance. No differences were detected for immunotherapy or combination therapies. Moreover, OS was similar for FGFR-3 altered (median 14.6m) and FGFR-3 wild- type (median 17.1 m) (HR 0.76, p=0.3). Conclusions: In our series, no significant differences related to response to first line therapy or survival was observed.

Association between PD1 mRNA and response to anti-PD1 monotherapy across multiple cancer types

Background

We hypothesized that the abundance of PD1 mRNA in tumor samples might explain the differences in overall response rates (ORR) observed following anti-PD1 monotherapy across cancer types.

Patients and methods

RNASeqv2 data from 10 078 tumor samples representing 34 different cancer types was analyzed from TCGA. Eighteen immune-related gene signatures and 547 immune-related genes, including PD1, were explored. Correlations between each gene/signature and ORRs reported in the literature following anti-PD1 monotherapy were calculated. To translate the in silico findings to the clinical setting, we analyzed the expression of PD1 mRNA using the nCounter platform in 773 formalin-fixed paraffin embedded (FFPE) tumor samples across 17 cancer types. To test the direct relationship between PD1 mRNA, PDL1 immunohistochemistry (IHC), stromal tumor-infiltrating lymphocytes (sTILs) and ORR, we evaluated an independent FFPE-based dataset of 117 patients with advanced disease treated with anti-PD1 monotherapy.

Results

In pan-cancer TCGA, PD1 mRNA expression was found strongly correlated (r > 0.80) with CD8 T-cell genes and signatures and the proportion of PD1 mRNA-high tumors (80th percentile) within a given cancer type was variable (0%-84%). Strikingly, the PD1-high proportions across cancer types were found strongly correlated (r = 0.91) with the ORR following anti-PD1 monotherapy reported in the literature. Lower correlations were found with other immune-related genes/signatures, including PDL1. Using the same population-based cutoff (80th percentile), similar proportions of PD1-high disease in a given cancer type were identified in our in-house 773 tumor dataset as compared with TCGA. Finally, the pre-established PD1 mRNA FFPE-based cutoff was found significantly associated with anti-PD1 response in 117 patients with advanced disease (PD1-high 51.5%, PD1-intermediate 26.6% and PD1-low 15.0%; odds ratio between PD1-high and PD1-intermediate/low = 8.31; P < 0.001). In this same dataset, PDL1 tumor expression by IHC or percentage of sTILs was not found associated with response.

Conclusions

Our study provides a clinically applicable assay that links PD1 mRNA abundance, activated CD8 T-cells and anti-PD1 efficacy.

Interim analysis of the fierce-21 phase 2 (P2) study of vofatamab (B-701), a selective inhibitor of FGFR3, as salvage therapy in metastatic urothelial carcinoma (mUC)

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Background: Patients (pts) with mUC with FGFR3 mutations who have failed platinum-based chemotherapy have a poor prognosis. Their response to immune checkpoint inhibitors appears diminished 10% or less compared to WT pts. 20% of mUC pts harbor FGFR3 mutations or fusions (M/F). Vofatamab is a fully human monoclonal antibody against FGFR3 that blocks activation of the wildtype and genetically activated receptor. FIERCE-21 is a Phase 1b/2 study designed to evaluate vofatamab monotherapy (VFM) or in combination with docetaxel (VFD). Methods: The P2 expansion enrolled mUC pts with FGFR3 M/F+ tumor (identified with FoundationONE CDx™), who failed ≥ 1 prior line of chemotherapy (including prior taxane for pts receiving VFM) or recurred ≤ 12 months of (neo)adjuvant chemotherapy. Pts had measurable disease and ECOG ≤ 1. Treatment consisted of vofatamab at 25 mg/kg alone and in combination with docetaxel at 75 mg/m2 q3w. Efficacy was assessed by investigators (RECIST 1.1). Primary objectives were safety and objective response-rate (ORR). Results: In the P2, 21 pts each received VFM and VFD. 57% of VFD pts had received at least 2, and 71% of VFM at least 3 prior lines of therapy. Best response to prior therapy was PD for 67% of VFD and 38% of VFM. The safety profile is consistent with previously reported data. TEAEs occurring in > 20% of pts were decreased appetite, diarrhea, pyrexia, asthenia, anemia, dyspnea, and fatigue. Most common vofatamab-related TEAEs in > 10% of pts were asthenia, diarrhea, decreased appetite and rash; all were Grade 1 or 2. In VFM, only 1 pt had a grade 3 TEAE and no pt discontinued treatment due to an AE. There were no cases of hyperphosphatemia, ocular or nail toxicity; 1 pt reported grade 2 skin toxicity. For pts receiving VM, median age was 70 yrs, ECOG 1 = 67%, Hgb < 10 g/dL 5%, liver metastases 19%. Responses have been seen in 7 pts to date including those receiving both VFM and VFD. Conclusions: Vofatamab both alone and combined with D in a q3w schedule are well tolerated with a low frequency of grade 3 TEAEs. Both VFM and VFD have demonstrated efficacy in terms of ORR. PFS/OS and DOR data will be presented at 7+ months for VFD and 9+ months for VFM. Clinical trial information: NCT02401542.