TALASUR trial: a single arm phase II trial assessing efficacy and safety of TALazoparib and Avelumab as maintenance therapy in platinum-Sensitive metastatic or locally advanced URothelial carcinoma.

BACKGROUND: Urothelial carcinoma (UC) is the ninth most commonly diagnosed cancer worldwide, with a 3.8/1 male to female ratio. Platinum-based chemotherapy is the first line standard of care for fit patients with advanced UC. However, despite a response rate (RR) for approximately half of patients receiving standard chemotherapy, durable responses are rare (median progression-free progression (PFS) around 8 months). Recently, immune checkpoint inhibitors (ICI) have emerged as new therapeutic options. Among them, Avelumab, an anti-PD-L1 antibody, was assessed in maintenance treatment, demonstrating an overall survival improvement in the JAVELIN Bladder-100 phase III trial. These findings led to its approval as first line maintenance therapy for patients with locally advanced or metastatic UC who have not progressed on prior platinum-containing chemotherapy. However, disease progression as best response was noticed for 37% of patients under Avelumab as maintenance treatment. UC has targetable genomic alterations, including DNA damage repair (DDR) alterations. DDR deficiency is known to major sensitivity to both platinum-based chemotherapy and PD-1/PD-L1 blockade and the combination of ICI and PARP inhibitors showed promising results. It therefore warrants to assess the interest of combining ICI plus PARP inhibitors as maintenance treatment in UC patients. METHODS: The TALASUR trial is a single-arm multicenter phase 2 study aiming to assess the antitumor activity of the combination of Avelumab with Talazoparib among patients with locally advanced/metastatic UC in maintenance therapy after platinum-based chemotherapy. The primary objective is to determine the efficacy of the combination, assessed through PFS. Secondary objectives are as follows: safety profile of the association, objective response, duration of tumoral response, disease control rate, time to subsequent therapy, quality of life. A blood and tumor collections will be also constituted. Patient will receive the combination therapy of daily oral Talazoparib (1 mg/day) and intra-venous Avelumab 800 mg on days 1 and 15, in a 28-day cycle. Fifty patients will be enrolled. DISCUSSION: Talazoparib with Avelumab combination may have additive activity when administrated jointly. We hypothesize that combination will increase the antitumor activity in UC first line maintenance setting with an acceptable safety profile. TRIAL REGISTRATION: NCT04678362, registered December 21, 2020. PROTOCOL VERSION:  Version 1.3 dated from 2020 09 11.

Carboplatin in metastatic castration-resistant prostate cancer patients with molecular alterations of the DNA damage repair pathway: the PRO-CARBO phase II trial.

Introduction: DNA damage repair genes are altered in 20-35% of metastatic castration-resistant prostate cancer (mCRPC). Poly-ADP (Adénosine Diphosphate)-ribose polymerase inhibitors (PARPi) showed significant activity for these selected tumors, especially with homologous recombination repair (HRR) deficiency. These alterations could also predict platinum sensitivity. Although carboplatin was inconclusive in unselected mCRPC, the literature suggests an anti-tumoral activity in mCRPC with HHR gene alterations. We aimed to assess the efficacy of carboplatin monotherapy in mCRPC patients with HRR deficiency. Methods: This prospective multicenter single-arm two-stage phase II addressed mCRPC men with HRR somatic and/or germline alterations, pretreated with ⩾2 taxane chemotherapy regimens and one androgen receptor pathway inhibitor. Prior PARPi treatment was allowed. Enrolled patients received intravenous carboplatin (AUC5) every 21 days for 6-9 cycles. The primary endpoint was the best response rate according to adapted PCWG3 guidelines: radiological response (RECIST 1.1 criteria) and/or biological response [⩾50% prostate-specific antigen (PSA) decline]. Results: A total of 15 out of 16 enrolled patients started carboplatin treatment. Genomic alterations were identified for BRCA2 (n = 5), CDK12 (n = 3), ATM (n = 3) CHEK2 (n = 2), CHEK1 (n = 1), and BRCA1 (n = 1) genes. Objective response (partial biological response + stable radiological response) was achieved in one patient (6.7%), carrying a BRCA2 mutation and not pre-treated with PARPi; stable disease was observed for five patients (33.5%). Among seven patients (46.7%) with previous PARPi treatment, four patients (57.1%) had a stable disease. The median progression-free and overall survivals were 1.9 [95% confidence interval (95% CI), 1.8-9.5] and 8.6 months (95% CI, 4.3-19.5), respectively. The most common severe (grade 3-4) treatment-related toxicities were thrombocytopenia (66.7%), anemia (66.7%), and nausea (60%). Overall, 8 (53.3%) patients experienced a severe hematological event. Conclusion: The study was prematurely stopped as pre-planned considering the limited activity of carboplatin monotherapy in heavily pre-treated, HHR-deficient mCRPC patients. Larger experience is needed in mCRPC with BRCA alterations. Trial registration: NCT03652493, EudraCT ID number 2017-004764-35.