Phase II study of cabazitaxel (CAB) plus enzalutamide (ENZ) in metastatic castration-resistant prostate cancer (mCRPC)

86

Background: There are six agents that improve survival in mCRPC, each administered as a single agent. Combinations of agents with distinct mechanisms of action have the potential to improve outcomes. Methods: We performed a multi-institution phase I/II study to examine safety and efficacy of CAB plus ENZ with mandatory granulocyte-colony stimulating factor support in mCRPC. Results: A sample size of 3 to 12 subjects for the phase I portion and 33 for the phase II portion provided 82% power to detect PSA response rate (decrease ≥90%) of 50% compared to the null hypothesis of 24%. The main eligibility criteria allowed prior abiraterone/prednisone (AAP) and docetaxel (in the metastatic hormone sensitive setting). Baseline characteristics: median age 69 years (47 - 82), median PSA 20.2 ng/dl (0.2 - 966.3); 7 subjects had visceral disease, 10 received prior AAP, and 8 received prior docetaxel. In the phase I portion, there were no dose limiting toxicities using CAB 25 mg/m2 IV Q3wks up to 10 cycles and ENZ 160 mg PO QD, hence this dosing was used for the phase II portion. 33 men with mCRPC were treated with CAB plus ENZ in the phase II arm. PSA response rates are listed in Table. Prior exposure to AAP decreased PSA response, but subjects who had prior AAP also had higher pre-treatment PSA. There were no treatment related deaths. Dose reduction of CAB to 20 mg/m2 was needed in 7 subjects. Over the course of the study, 14 Grade 3 adverse events occurred that were deemed possibly related to treatment: fatigue (n=2, 6%), febrile neutropenia (n=2, 6%), leukopenia (n=2, 6%), thrombocytopenia (n=2, 6%), anemia (n=1, 3%), hypertension (n=1, 3%), leukocytosis (n=2, 6%), fracture (n=1, 3%), failure to thrive (n=1, 3%). Conclusions: CAB plus ENZ was tolerable and associated with promising anti-tumor activity, particularly in abiraterone-naïve subjects. Further evaluation of this regimen is warranted. This project was managed by the Prostate Cancer Clinical Trials Consortium and funded by Astellas Inc. and Sanofi. Clinical trial information: NCT02522715. [Table: see text]

KEYNOTE-052: Phase 2 study evaluating first-line pembrolizumab (pembro) in cisplatin-ineligible advanced urothelial cancer (UC)— Updated response and survival results

4546

Background: Initial results of the phase 2 KEYNOTE-052 (NCT02335424) study led to approval of pembro for cisplatin-ineligible patients (pts) with advanced UC. Updated results representing follow-up of over 2 y since last pt enrolled are presented. Methods: Pts had confirmed advanced UC, were cisplatin-ineligible (ECOG PS 2, CrCl ≥30 to ˂60 mL/min, grade ≥2 neuropathy/hearing loss, NYHA Class III heart failure), and received no prior chemotherapy for metastatic disease. Pts received pembro 200 mg IV Q3W until progression, unacceptable toxicity, withdrawal, or 24 mo of therapy, whichever occurred first. Primary end point was confirmed ORR (RECIST v1.1, independent central review). Key secondary end points: duration of response (DOR), overall survival (OS), and safety. Data cutoff was September 26, 2018. Results: Among pts assessed (N = 370), median age was 74 y, 85% had visceral disease, and 30% were PD-L1 positive (combined positive score [CPS] ≥10). Median follow-up was 11.4 mo (range, 0.1-41.2) for all pts and 29.3 mo (range 7-41.2) for responders. Confirmed ORR was 29% (95% CI, 24-34): complete response, 9% (n = 33); partial response, 20% (n = 73). Median DOR was 30.1 mo (95% CI, 18.1-not reached [NR]); 67% and 52% of pts had DOR ≥12 and ≥24 mo, respectively. Median OS was 11.3 mo (range 9.7-13.1); 12- and 24-mo OS rates were 47% and 31%, respectively. In pts with CPS ˂10 (n = 251) and ≥10 (n = 110), respectively, confirmed ORR was 20% (95%CI, 16-26) and 47% (95% CI, 38-57). Median DOR for pts with CPS < 10 and ≥10 was 18.2 mo (95% CI, 9.7-NR) and NR (95% CI, 18.1-NR); DOR ≥24 mo was 45% and 57%, respectively. Median OS for pts with CPS < 10 and ≥10 was 9.7 mo (95% CI, 7.6-11.5) and 18.5 mo (95% CI, 12.2-28.5); 24-mo OS rates were 24% and 47% respectively. Treatment-related adverse events (AEs) occurred in 67% of pts. Most common were fatigue and pruritus (18% each); 21% were grade ≥3, including 1 death (myositis). Conclusions: With extended follow-up, pembro continued to elicit clinically meaningful, durable antitumor activity in cisplatin-ineligible pts with advanced UC and was more pronounced in those with PD-L1 expression CPS ≥10. Pembro safety profile was as expected. Clinical trial information: NCT02335424.

A phase II trial of olaparib and durvalumab in metastatic BRCA wild type triple-negative breast cancer

TPS1111

Background: There is an urgent need to develop novel non chemotherapy treatments for metastatic triple negative breast cancer (mTNBC) patients who otherwise have a poor prognosis. Immune checkpoint blockade (ICB) and PARP inhibitors (PARPi) have independently shown promise for the treatment of mTNBC, and the combination has shown early benefit in the MEDIOLA and TOPACIO trials. This trial looks to 1) evaluate the efficacy of the combination of the PARPi olaparib and the PD-L1 inhibitor durvalumab, and 2) perform extensive multi-omics including protein based image analytics (multiplex IHC, cyclic immunofluorescence) on serial biopsies to identify predictive biomarkers and resistance mechanisms. Methods: Trial Design: This is a single-arm phase II study to assess the efficacy of the combination of olaparib and durvalumab in BRCA-wildtype mTNBC. mTNBC participants will undergo a pre-treatment biopsy, then will start a 4 week induction treatment with olaparib (300 mg PO BID). At the end of 4 weeks of single agent therapy, participants will undergo a repeat on-treatment biopsy, following which durvalumab (1500 mg IV every 4 weeks) will be added to olaparib. Participants will also be offered an optional biopsy on progression. Endpoints: The primary endpoint of this study is overall response rate (ORR) to olaparib and durvalumab therapy. Secondary efficacy endpoints include clinical benefit rate, duration of response, progression-free, and overall survival. The incidence and severity of on-treatment adverse events will be collected per CTCAE 5.0. Statistical Methods: 28 participants are planned for enrollment to this study. A 2-stage analysis will be performed using a Simon 2-stage Minimax design. The null (ICB alone) and alternative (ICB + PARPi) hypotheses are: H0: π = 0.15 and Ha: π = 0.35. For the primary endpoint, a total sample size of 28 participants will achieve 80% power to detect the ORR difference of 0.20 with one-sided type I error =0.05. The trial will be terminated in stage I if 2 or less out of the first 15 participants respond. If the trial goes on to the stage II, a total of 28 participants will be studied. If the total number responding is less than or equal to 7, the combination is rejected. Current Enrollment: The study was activated on 1/7/2019. To date, 3 out of 15 patients have been accrued to stage I of the study Clinical trial information: NCT03801369.

Abstract P2-09-03: Updated efficacy of first or second-line pembrolizumab (pembro) plus capecitabine (cape) in metastatic triple negative breast cancer (mTNBC) and correlations with baseline lymphocyte and naïve CD4+ T-cell count

Background: In mTNBC, anti-PD-1/L1 monotherapy is most effective when administered early in the course of disease, with recent trials demonstrating overall response rates (ORR) of 23-26% in the first-line setting and 5-6% in later lines. This may reflect iatrogenic lymphopenia from preceding cytotoxic chemotherapy. Furthermore, curative-intent chemotherapy is associated with prolonged suppression of naïve CD4+ cells, a T-cell subset that may play a critical role in the generation of de novo anti-tumor immune responses. We present the final clinical results of a pilot study evaluating the safety and efficacy of combining pembrolizumab plus standard-of-care capecitabine in the first/second-line mTNBC setting. We also explore potential associations between clinical benefit and lymphopenia, preceding chemotherapy, and absolute naïve CD4+ counts.

Methods: In a pilot study, we evaluated the tolerability and preliminary efficacy of concurrent pembro (200mg IV q21 day) plus investigator-selected 1st/2nd line paclitaxel (80mg/m2 IV weekly) or oral cape (2,000mg BID, weekly 1 on/1 off). The primary endpoint was tolerability, defined as the proportion of subjects receiving &gt;6 weeks concurrent therapy without dose discontinuation with toxicities reported per CTCAE v4.0. The secondary endpoint was 12-week objective response rate (ORR) by RECIST1.1. Exploratory endpoints included peripheral blood cell enumeration by real-time flow cytometry and routine clinical laboratory. Naïve CD4+ cells were defined as CD45+ CD3+ TCRab+ CD4+ CD45RA+ CCR7+. Here, we report the results of the pilot phase of the cape cohort (NCT02734290).

Results: Twelve of 14 subjects were treated in the first-line setting. All subjects (14/14, 100%) tolerated cape+pembro for &gt;6 weeks, with toxicities consistent with monotherapy cape experience (diarrhea: grade I-II 50%, grade III 7%; hand-foot: grade I-II 71%) that improved with dose-reduction as needed. At 12 weeks, the ORR was 6/14 (42.9%), and the clinical benefit rate (ORR + stable disease) was 8/14 (57.1%). Depressed absolute lymphocyte count at baseline (ALC&lt;1.0/uL: 33% CBR; ALC≥1.0/uL: 75% CBR) and recent exposure to cytotoxic chemotherapy (&lt;6 months: 33% CBR; &gt;6 months: 75% CBR) were associated with reduced clinical benefit. By flow cytometry, subjects experiencing clinical benefit had higher baseline absolute naïve CD4+ counts (average 283 cells/uL v. 93 cells/uL, p=.069).

Conclusions: This study met the primary endpoint of safety for cape plus pembro in mTNBC, with encouraging clinical activity. These data are supportive of further studies evaluating combination chemotherapy plus anti-PD-1/L1 mTNBC. We observed greater clinical benefit in subjects with non-suppressed ALC, less exposure to recent chemo, and higher baseline naïve CD4+ counts, suggesting that iatrogenic immunosuppression can impair response to immune checkpoint therapy in mTNBC. These findings should be confirmed in ongoing randomized trials of immune checkpoint +/- chemotherapy in mTNBC, and should be considered in the design of future clinical trials.

Citation Format: Page DB, Pucilowska J, Bennetts L, Kim I, Sanchez K, Martel M, Conlin A, Moxon N, Mellinger S, Acheson A, Kemmer K, Mitri Z, Vuky J, Ahn J, Abaya C, Manigault T, Basho R, Urba WJ, McArthur HL. Updated efficacy of first or second-line pembrolizumab (pembro) plus capecitabine (cape) in metastatic triple negative breast cancer (mTNBC) and correlations with baseline lymphocyte and naïve CD4+ T-cell count [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P2-09-03.

Abstract CT069: Baseline gene expression patterns of CDK4/6 inhibitor-naïve or -refractory HR+, HER2- advanced breast cancer in the phase Ib study of ribociclib plus everolimus plus exemestane

Background: Preclinical data suggest that combination of endocrine therapy (ET) with a cyclin-dependent kinase 4/6 inhibitor (CDK4/6i) and mammalian target of rapamycin inhibitor (mTORi) may overcome prior treatment resistance in hormone receptor-positive (HR+), human epidermal growth factor receptor 2-negative (HER2-) advanced breast cancer (ABC). The Phase Ib CLEE011X2106 study (NCT01857193) is investigating ribociclib (RIB; CDK4/6i) + everolimus (EVE; mTORi) + exemestane (EXE; ET) in patients with HR+, HER2- ABC resistant to letrozole or anastrozole. The objective of this analysis is to characterize baseline gene expression patterns in the CDK4/6i-naïve and -refractory groups, and assess the potential correlation with clinical activities.

Methods: Postmenopausal women with HR+, HER2- ABC resistant to letrozole or anastrozole, and who had received no prior CDK4/6i or whose disease had progressed on or within 1 month of CDK4/6i therapy, were enrolled in the CDK4/6i-naïve and -refractory dose expansion groups, respectively. More than 1 line of chemotherapy for ABC or prior treatment with EXE or an mTORi was not permitted. Patients received RIB (300 mg, 3-weeks on/1-week off) + EVE (2.5 mg, continuous) + EXE (25 mg, continuous) until disease progression or study discontinuation. Baseline tumor samples (collected after CDK4/6i therapy in the CDK4/6i-refractory group) were assessed for mRNA expression using the NanoString 230-gene nCounter® GX Human Cancer Reference panel.

Results: As of May 15, 2017, the 24-week clinical benefit rate was 56% (9/16) in the CDK4/6i-naïve group and 24% (4/17) in the -refractory group. Baseline tumor mRNA expression was evaluable in 14 patients: CDK4/6i naïve, n=8 (best response: 7 stable disease [SD], 1 progressive disease [PD]); CDK4/6i refractory, n=6 (2 SD, 4 PD). Across all patients (both groups), those with SD tended to have higher ESR1 expression compared with those experiencing PD, with a trend for higher baseline ESR1 expression in the CDK4/6i-naïve group compared with the -refractory group. Also across all patients, higher overall baseline expression of cell cycle control genes and mitogen-activated protein kinase (MAPK) pathway genes appeared to trend with PD. Additionally, in the CDK4/6i-refractory group, there was a trend for higher CDK2 and/or CCNE1 expression in patients with PD compared with SD. A heat map of 24 genes indicated differences in gene expression patterns between the CDK4/6i-naïve and -refractory groups.

Conclusions: Gene expression patterns differ between CDK4/6i-naïve and -refractory tumors. Higher expression of cell cycle control genes (particularly CDK2 and CCNE1) and MAPK pathway genes appears to trend with resistance to the RIB + EVE + EXE combination after progression on prior CDK4/6i. Due to the small number of samples, further investigation is needed.

Citation Format: Aditya Bardia, Shanu Modi, Javier Cortes, Mario Campone, Luc Dirix, Brigette Ma, J Thaddeus Beck, Jorge Chaves, Amy Weise, Jacqueline Vuky, Gilberto Lopes, Miguel Gil-Gil, Xiaochun Liu, Wei He, Faye Su, Michelle Miller, Mariana Chavez-MacGregor. Baseline gene expression patterns of CDK4/6 inhibitor-naïve or -refractory HR+, HER2- advanced breast cancer in the phase Ib study of ribociclib plus everolimus plus exemestane [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr CT069.

First-line pembrolizumab in cisplatin-ineligible patients with locally advanced and unresectable or metastatic urothelial cancer (KEYNOTE-052): a multicentre, single-arm, phase 2 study

BACKGROUND

More than half of all patients with advanced urothelial cancer cannot receive standard, first-line cisplatin-based chemotherapy because of renal dysfunction, poor performance status, or other comorbidities. We assessed the activity and safety of first-line pembrolizumab in cisplatin-ineligible patients with locally advanced and unresectable or metastatic urothelial cancer.

METHODS

In this multicentre, single-arm, phase 2 study (KEYNOTE-052), cisplatin-ineligible patients with advanced urothelial cancer who had not been previously treated with systemic chemotherapy were recruited from 91 academic medical centres in 20 countries. Enrolled patients received intravenous pembrolizumab 200 mg every 3 weeks. The primary endpoint was objective response (the proportion of patients who achieved complete or partial response) in all patients and by PD-L1 expression status according to the Response Evaluation Criteria in Solid Tumors, version 1.1, as assessed by independent central review. PD-L1 expression was assessed in tumour and inflammatory cells from tumour biopsies provided at study entry. Activity and safety were analysed in all patients who received at least one dose of pembrolizumab (all-patients-treated population). This study is registered with ClinicalTrials.gov, number NCT02335424, and follow-up is ongoing.

FINDINGS

Between Feb 24, 2015, and Aug 8, 2016, 374 patients were enrolled and 370 patients received at least one dose of pembrolizumab. 89 (24%, 95% CI 20-29) of 370 patients had a centrally assessed objective response, and as of Sept 1, 2016 (data cutoff), 74 (83%) of 89 responses were ongoing. Median follow-up was 5 months (IQR 3·0-8·6). A PD-L1-expression cutoff of 10% was associated with a higher frequency of response to pembrolizumab; 42 (38%, 95% CI 29-48) of 110 patients with a combined positive score of 10% or more had a centrally assessed objective response. The most common grade 3 or 4 treatment-related adverse events were fatigue (eight [2%] of 370 patients), alkaline phosphatase increase (five [1%]), colitis, and muscle weakness (both four [1%]). 36 (10%) of 370 patients had a serious treatment-related adverse event. 17 (5%) of 370 patients died from non-treatment-related adverse events associated with death, and one patient died from treatment-related adverse events (myositis in addition to grade 3 thyroiditis, grade 3 hepatitis, grade 3 pneumonia, and grade 4 myocarditis).

INTERPRETATION

First-line pembrolizumab has antitumour activity and acceptable tolerability in cisplatin-ineligible patients with urothelial cancer, most of whom were elderly, had poor prognostic factors, or had serious comorbidities. In view of this result, pembrolizumab has become a new treatment option for patients who are cisplatin-ineligible or not suitable candidates for chemotherapy. Pembrolizumab in the first-line setting is being further assessed in the phase 3 KEYNOTE-361 trial (ClinicalTrials.gov, NCT02335424).

FUNDING

Merck & Co.

Biomarker findings and mature clinical results from KEYNOTE-052: First-line pembrolizumab (pembro) in cisplatin-ineligible advanced urothelial cancer (UC)

4502

Background: Comorbidities and renal impairment preclude many with advanced UC from receiving chemotherapy. Initial results from the phase 2 KEYNOTE-052 (NCT02335424) trial suggested first-line pembro is active and safe in cisplatin-ineligible advanced UC. We present updated efficacy and safety data (all pts have ≥6 mo follow-up) and evaluate biomarkers correlated with outcomes. Methods: Eligibility criteria included cisplatin-ineligible (ECOG PS 2, CrCl ≥30- < 60 mL/min, grade ≥2 neuropathy/hearing loss, NYHA Class 3 heart failure), advanced UC, and no prior systemic chemotherapy. Pts received pembro 200 mg IV Q3W. Imaging was performed at wk 9, then Q6W for the first year, and Q12W thereafter. Primary end point was confirmed ORR (RECIST v1.1, independent review). Efficacy and safety were assessed in the 370 pts with ≥1 pembro dose. The associations of an 18-gene expression profile (GEP) and IHC PD-L1 combined positive score (CPS) with ORR were evaluated. Results: As of the Dec 19, 2016, data cutoff, ORR was 29% (95% CI, 24-34): 25 (7%) and 81 (22%) pts achieved complete and partial responses. Another 69 pts (19%) had stable disease as best response, for a clinical benefit rate of 47%. Median time to response was 2 mo (range, 1-5). At a median follow-up of 8 mo (range, 0.1-20) across all pts, median duration of response was not reached (range, 1+-18+ mo). 74% of responses were ongoing. Any-grade and grade ≥3 drug-related AEs occurred in 239 (65%) and 68 (18%) pts. Immune-mediated AEs occurred in 76 (21%) pts. Evidence supporting a positive association with response was seen in the first 100 pts for both biomarkers (GEP, n = 72, P = 0.007, ROC AUC 0.69; CPS, n = 96, P= 0.111, ROC AUC 0.58); biomarker data for all pts will be presented. ORR in the 110 pts with CPS ≥10% was 47% (95% CI, 38-57). Conclusions: Results confirm that pembro elicits clinically meaningful, durable responses in cisplatin-ineligible advanced UC. Consistent with PD-1 pathway biology, biomarkers (GEP and CPS) showed the expected trends of positive association with response to pembro. Pembro was well tolerated across cisplatin-ineligible pts, including elderly and pts with poor performance status. Clinical trial information: NCT02335424.

Pembrolizumab as first-line therapy in cisplatin-ineligible advanced urothelial cancer: Results from the total KEYNOTE-052 study population

284

Background: Treatment options are limited for patients (pts) with advanced urothelial cancer (UC) ineligible to receive cisplatin-based chemotherapy. Interim results from the first 100 pts enrolled in the phase 2, open-label KEYNOTE-052 (ClinicalTrials.gov, NCT02335424) study suggested first-line pembrolizumab (pembro) had antitumor activity and acceptable safety in this pt population. Results from the fully enrolled study are presented. Methods: Key eligibility criteria included age ≥ 18 y, advanced UC of the renal pelvis, ureter, bladder, or urethra, cisplatin ineligibility (ECOG PS 2, creatinine clearance ≥ 30 to < 60 mL/min, grade ≥ 2 neuropathy or hearing loss, NYHA Class 3 heart failure), no prior systemic chemotherapy for advanced UC, measurable disease per RECIST v1.1, ECOG PS 0-2, and provision of a tumor sample for biomarker analyses. Pembro 200 mg was administered every 3 wk. Imaging was performed at wk 9, then every 6 wk for the first year, and every 12 wk thereafter. The primary end point was confirmed overall response rate (ORR; RECIST v1.1, independent review). Efficacy data are presented for pts with ≥ 4 mo follow-up, and safety data are presented for all pts. Results: In total, 370 pts were enrolled; median age was 74 y (range, 34-94 y); 42% had an ECOG PS 2. Reasons for cisplatin ineligibility included ECOG PS 2 (32%), renal dysfunction (49%), and both ECOG PS 2 and renal dysfunction (10%). ORR (95% CI) was 27% (22%-32%) among pts with ≥ 4 mo follow-up (n = 307); 6% of pts achieved a complete response. Among the ≥ 4 mo follow-up group, median (range) time to response was 2.0 (1.6-4.8) mo; median (range) duration of response was not reached (1+ to 14+ mo). 78% of responders had a response for ≥ 6 mo (KM estimate). PFS and OS rates at 6 mo were 31% and 67%, respectively (KM estimate). Any grade and grade ≥ 3 drug-related AEs occurred in 229 (62%) and 58 (16%) pts. 19 (5%) pts discontinued treatment because of a drug-related AE. Conclusions: Results from the fully enrolled KEYNOTE-052 study confirm that pembro elicits clinically meaningful and durable responses in cisplatin-ineligible pts with UC, including elderly pts and those with poor performance status. Clinical trial information: NCT02335424.

A Phase 1/2 Trial of a Combination of Paclitaxel and Trastuzumab With Daily Irradiation or Paclitaxel Alone With Daily Irradiation After Transurethral Surgery for Noncystectomy Candidates With Muscle-Invasive Bladder Cancer (Trial NRG Oncology RTOG 0524)

PURPOSE

Bladder preservation therapy is an effective treatment for muscle-invasive urothelial carcinoma (UC). In this study we treated noncystectomy candidates with daily radiation and weekly paclitaxel for 7 weeks. Patients whose tumors showed her2/neu overexpression were additionally treated with weekly trastuzumab.

METHODS AND MATERIALS

Sixty-eight evaluable patients were treated with radiation therapy and either paclitaxel + trastuzumab (group 1) or paclitaxel alone (group 2). Groups were assigned on the basis of her2/neu immunohistochemistry results. Patients received 1.8-Gy fractions to a total dose of 64.8 Gy. The primary endpoint of the study was treatment-related toxicity, and secondary endpoints included complete response (CR) rate, protocol completion rate, and survival.

RESULTS

A total of 20 evaluable patients were treated in group 1 and 46 patients in group 2. Acute treatment-related adverse events (AEs) were observed in 7 of 20 patients in group 1 (35%) and 14 of 46 patients in group 2 (30.4%). Protocol therapy was completed by 60% (group 1) and 74% (group 2) of patients. Most incompletions were due to toxicity, and the majority of AEs were gastrointestinal, including 1 grade 5 AE (group 1). Two other deaths (both in group 2) were unrelated to protocol therapy. No unexpected cardiac, hematologic, or other toxicities were observed. The CR rate at 1 year was 72% for group 1 and 68% for group 2.

CONCLUSIONS

In patients with muscle-invasive UC who are not candidates for cystectomy, daily radiation combined with paclitaxel is an effective treatment strategy with a high completion rate and moderate toxicity. In patients with her2/neu-positive tumors, a group generally considered to have worse outcomes, the addition of trastuzumab appears to result in comparable efficacy and toxicity. Further biomarker-driven trials should be undertaken in advancing treatment of this challenging disease.

The initial report of RTOG 0524: Phase I/II trial of a combination of paclitaxel and trastuzumab with daily irradiation or paclitaxel alone with daily irradiation following transurethral surgery for noncystectomy candidates with muscle-invasive bladder cancer

LBA287

Background: Most patients (pts) with muscle-invasive bladder urothelial carcinoma (UC) undergo definitive local treatment with radical cystectomy. Up to 50% of pts with UC overexpress HER2/neu, which may be associated with reduced responsiveness to chemoradiation and reduced survival. Many pts with UC have comorbidities that preclude surgery, creating a traditionally underserved population with worse outcomes. RTOG 0524 evaluated the safety and efficacy of trimodality, organ-preserving therapy in pts not suitable for cystectomy. Methods: Pts with invasive bladder UC (stages T2-T4a, N0-1, M0) underwent cystoscopic tumor resection. Tumors were analyzed by HER2/neu immunohistochemistry (IHC) and assigned to chemotherapy group I (IHC 2+ or 3+; paclitaxel and trastuzumab) or II (IHC negative or 1+; paclitaxel alone). Concurrent weekly paclitaxel (50 mg/m2), weekly trastuzumab (group I only) and daily radiation (64.8 Gy total in 36 fractions) were given for seven consecutive weeks. Results: 21 eligible patients were entered in group I and 47 in group 2, with median ages of 80 and 73, respectively. The primary endpoint was acute protocol-defined toxicity related to treatment. Acute toxicity was observed in 7/21 pts (33%) in group I and 14/47 pts (30%) in group II. Most common grade > 3 adverse events in groups I and II were marrow suppression (43% and 17%), diarrhea (33% and 30%), and hyponatremia (14% and 4%). Three deaths on study were attributed to colonic perforation, pneumonia, and sudden death. Radiation completion rates were 72% and 85% in the two groups, and full-dose chemotherapy completion rates were 52% and 51%. Evaluation by cystoscopy and/or tumor biopsy at 12 weeks noted complete response in 9/13 pts (69%) in group I, in 19/33 pts (58%) in group II, and was not performed in the remaining pts. Conclusions: Trimodality bladder-preserving therapy is an appropriate treatment in noncystectomy candidates with invasive UC. The response rate for HER2/neu-targeted therapy is encouraging but may increase certain adverse events in this challenging population. Clinical trial information: NCT00238420.

Randomized trial to assess the impact of venlafaxine and soy protein on hot flashes and quality of life in men with prostate cancer

PURPOSE

Hot flashes occur in approximately 80% of androgen-deprived men. Few intervention studies have been conducted to relieve hot flashes in men.

PATIENTS AND METHODS

Eligible androgen-deprived men were randomly assigned to one of four daily regimens (2 × 2 factorial design) for 12 weeks: milk protein powder and placebo pill, venlafaxine and milk protein powder, soy protein powder and placebo pill, or venlafaxine and soy protein powder. The primary end point was hot flash symptom severity score (HFSSS), defined as number of hot flashes times severity. The secondary end point was quality of life (QoL), assessed by using the Functional Assessment of Cancer Therapy-Prostate.

RESULTS

In all, 120 men age 46 to 91 years participated. Most were white (78%) and overweight or obese (83%). Toxicity was minimal. Neither venlafaxine nor soy protein alone or in combination had a significant effect on HFSSS. Soy protein, but not venlafaxine, improved measures of QoL.

CONCLUSION

In androgen-deprived men, neither venlafaxine nor soy proved effective in reducing hot flashes. Interventions that appear effective for decreasing hot flashes in women may not always turn out to be effective in men.

Phase II trial of neoadjuvant docetaxel and CG1940/CG8711 followed by radical prostatectomy in patients with high-risk clinically localized prostate cancer

BACKGROUND

Prostate cancer (PC) is the most commonly diagnosed noncutaneous malignancy in American men. PC, which exhibits a slow growth rate and multiple potential target epitopes, is an ideal candidate for immunotherapy. GVAX for prostate cancer is a cellular immunotherapy, composed of PC-3 cells (CG1940) and LNCaP cells (CG8711). Each of the components is a prostate adenocarcinoma cell line that has been genetically modified to secrete granulocyte-macrophage colony-stimulating factor. Hypothesizing that GVAX for prostate cancer could be effective in a neoadjuvant setting in patients with locally advanced disease, we initiated a phase II trial of neoadjuvant docetaxel and GVAX. For the trial, the clinical effects of GVAX were assessed in patients undergoing radical prostatectomy (RP).

METHODS

Patients received docetaxel administered at a dose of 75 mg/m(2) every 3 weeks for 4 cycles. GVAX was administered 2-3 days after chemotherapy preoperatively for four courses of immunotherapy. The first dose of GVAX was a prime immunotherapy of 5×10(8) cells. The subsequent boost immunotherapies consisted of 3×10(8) cells. After RP, patients received an additional six courses of immunotherapy. Pathologic complete response, toxicity, and clinical response were assessed. The primary endpoint of the trial was a pathologic state of pT0, which is defined as no evidence of cancer in the prostate.

RESULTS

Six patients completed neoadjuvant docetaxel and GVAX therapy. No serious drug-related adverse events were observed. Median change in prostate-specific antigen (PSA) following neoadjuvant therapy was 1.47 ng/ml. One patient did not undergo RP due to the discovery of positive lymph nodes during exploration. Of the five patients completing RP, four had a downstaging of their Gleason score. Undetectable PSA was achieved in three patients at 2 months after RP and in two patients at 3 years after RP.

CONCLUSIONS

Neoadjuvant docetaxel/GVAX is safe and well tolerated in patients with high-risk locally advanced PC. No evidence of increased intraoperative hemorrhage or increased length of hospital stay postoperatively was noted. These results justify further study of neoadjuvant immunotherapy.

Phase II study to assess the efficacy, safety and tolerability of the mitotic spindle kinesin inhibitor AZD4877 in patients with recurrent advanced urothelial cancer

BACKGROUND

AZD4877 is a potent inhibitor of the mitotic spindle kinesin, Eg5. Early-phase clinical studies in a broad range of cancers showed that AZD4877 is well tolerated. This Phase II study evaluated the efficacy, safety and pharmacokinetics (Cmax) of AZD4877 in patients with previously treated advanced urothelial cancer (ClinicalTrials.gov identifier NCT00661609).

PATIENTS AND METHODS

AZD4877 25 mg was administered once-weekly for 3 weeks of each 4-week cycle until disease progression, death, unacceptable toxicity or withdrawal. The primary objective was to determine the objective response rate (RECIST). Recruitment was to be halted if ≤ 2 of the first 20 evaluable patients achieved an objective tumor response. Cmax was assessed on days 1 and 8 of cycle 1.

RESULTS

None of the first 20 patients evaluable for efficacy achieved an objective response; enrollment was therefore halted. During this initial analysis, a further 21 patients were recruited. Overall, 39 patients were evaluable for efficacy, including one with confirmed partial response (PR) and seven patients with stable disease for ≥ 8 weeks (including one unconfirmed PR). The most commonly reported treatment-related adverse events (TRAEs) were neutropenia (22 patients), fatigue (12), leukopenia (7) and constipation (6); the most commonly reported grade ≥ 3 TRAE was neutropenia (21). Four patients had serious TRAEs. On days 1 and 8, the geometric mean Cmax of AZD4877 was 138 ng/ml (CV = 75 %) and 144 ng/ml (CV = 109 %), respectively.

CONCLUSIONS

AZD4877 was generally tolerable in patients with advanced urothelial cancer. Given the limited clinical efficacy, further development of AZD4877 in urothelial cancer is not planned.

The evaluation of flaxseed for hot flashes: Results of a randomized, controlled trial, NCCTG study N08C7

CRA9015

Background: Hot flashes are a common symptom during the menopause transition or following breast cancer treatment that can negatively impact the quality of life for many women. Preliminary data have suggested that flaxseed, a rich source of dietary lignans, may be a potentially effective treatment for hot flashes. Methods: A phase III randomized, placebo controlled trial was conducted to evaluate the efficacy of flaxseed in reducing hot flashes. Postmenopausal women were randomly assigned to a flaxseed bar (providing 410 mg of lignans) for 6 weeks vs a placebo bar. Participants completed daily prospective, self report hot flash diaries during the baseline week and then began eating one study bar per day for 6 weeks, while continuing to record their daily hot flashes. The intra-patient difference in hot flash activity between baseline and the last treatment week was the primary endpoint. Side effects of the bars were evaluated through self report and CTC assessment. Results: Between October and December 2009, 188 women were enrolled onto this trial. Mean hot flash scores were reduced by 4.9 units in the flaxseed group and 3.5 in the placebo group (p=0.29). In both groups, a little over a third of the women received a 50% reduction in their hot flash scores. Only one side effect was significantly different between groups, that being grade 1 pruritis, which was more common (7%) in the placebo group versus 1% in the flaxseed group. Both groups reported increased abdominal distension, flatulence, diarrhea and nausea. Adherence and ability to detect treatment assignment did not differ between groups. Conclusions: The results of this trial do not support the use of 410 mg of flaxseed lignans for the reduction of hot flashes. The gastrointestinal side effects seen in both groups were likely due to the fiber content in the flaxseed and placebo bars.

A phase II study of everolimus in combination with imatinib for previously treated advanced renal carcinoma

PURPOSE

This phase II study evaluated the activity of combined treatment with the mTOR inhibitor everolimus and the PDGFR inhibitor imatinib in patients with previously-treated, advanced renal carcinoma. The primary endpoint was estimation of the 3-month progression-free rate.

PATIENTS AND METHODS

Eligible patients had metastatic or unresectable clear cell renal carcinoma, at least one prior systemic therapy, no prior mTOR inhibitor therapy, performance status 0-2, and measurable disease. Treatment consisted of everolimus 2.5 mg p.o. daily and imatinib 600 mg p.o. daily. The primary endpoint was the 3-month progression-free rate.

RESULTS

The study was closed after the first 19 patients because of an insufficient number of patients who were progression-free at 3 months. The 3-month progression-free rate was 49% (95% C.I. 23%, 72%) and the median progression-free survival was 2.9 months (95% C.I. 1.9, 6.2). Toxicities with an incidence of >  50% included nausea, elevated serum creatinine, edema, anemia, hypocalcemia, fatigue, diarrhea, vomiting, and dyspnea, and leukopenia.

CONCLUSION

The combination of everolimus with imatinib in previously treated patients with advanced renal carcinoma did not result in a sufficient 3-month progression-free rate to warrant further investigation of this combination.