ENGOT-en11/GOG-3053/KEYNOTE-B21: a randomised, double-blind, phase III study of pembrolizumab or placebo plus adjuvant chemotherapy with or without radiotherapy in patients with newly diagnosed, high-risk endometrial cancer.

BACKGROUND: Pembrolizumab plus chemotherapy provides clinically meaningful benefit as first-line therapy for advanced (locoregional extension and residual disease after surgery)/metastatic/recurrent mismatch repair-proficient (pMMR) and mismatch repair-deficient (dMMR) endometrial cancer, with greater magnitude of benefit in the dMMR phenotype. We evaluated the addition of pembrolizumab to adjuvant chemotherapy (with/without radiation therapy) among patients with newly diagnosed, high-risk endometrial cancer without any residual macroscopic disease following curative-intent surgery. METHODS: We included patients with histologically confirmed high-risk [International Federation of Gynecology and Obstetrics (FIGO) stage I/II of non-endometrioid histology or endometrioid histology with p53/TP53 abnormality, or stage III/IVA of any histology] endometrial cancer following surgery with curative intent and no evidence of disease postoperatively, with no prior radiotherapy or systemic therapy. Patients were randomised to pembrolizumab 200 mg or placebo every 3 weeks (Q3W) for six cycles added to carboplatin-paclitaxel followed by pembrolizumab 400 mg or placebo every 6 weeks (Q6W) for six cycles per treatment assignment. Radiotherapy was at the investigator's discretion. The primary endpoints were investigator-assessed disease-free survival (DFS) and overall survival in the intention-to-treat population. RESULTS: A total of 1095 patients were randomised (pembrolizumab, n = 545; placebo, n = 550). At this interim analysis (data cut-off, 4 March 2024), 119 (22%) DFS events occurred in the pembrolizumab group and 121 (22%) occurred in the placebo group [hazard ratio 1.02, 95% confidence interval (CI) 0.79-1.32; P = 0.570]. Kaplan-Meier estimates of 2-year DFS rates were 75% and 76% in the pembrolizumab and placebo groups, respectively. The hazard ratio for DFS was 0.31 (95% CI 0.14-0.69) in the dMMR population (n = 281) and 1.20 (95% CI 0.91-1.57) in the pMMR population (n = 814). Grade ≥3 adverse events (AEs) occurred in 386 of 543 (71%) and 348 of 549 (63%) patients in the pembrolizumab and placebo groups, respectively. No treatment-related grade 5 AEs occurred. CONCLUSIONS: Adjuvant pembrolizumab plus chemotherapy did not improve DFS in patients with newly diagnosed, high-risk, all-comer endometrial cancer. Preplanned subgroup analyses for stratification factors suggest that pembrolizumab plus chemotherapy improved DFS in patients with dMMR tumours. Safety was manageable. TRIAL REGISTRATION: ClinicalTrials.gov, NCT04634877; EudraCT, 2020-003424-17. RESEARCH SUPPORT: Merck Sharp & Dohme LLC, a subsidiary of Merck & Co., Inc., Rahway, NJ, USA.

Overall survival in patients with endometrial cancer treated with dostarlimab plus carboplatin-paclitaxel in the randomized ENGOT-EN6/GOG-3031/RUBY trial.

BACKGROUND: Part 1 of the RUBY trial (NCT03981796) evaluated dostarlimab plus carboplatin-paclitaxel compared with placebo plus carboplatin-paclitaxel in patients with primary advanced or recurrent endometrial cancer (EC). At the first interim analysis, the trial met one of its dual primary endpoints with statistically significant progression-free survival benefits in the mismatch repair-deficient/microsatellite instability-high (dMMR/MSI-H) and overall populations. Overall survival (OS) results are reported from the second interim analysis. PATIENTS AND METHODS: RUBY is a phase III, global, double-blind, randomized, placebo-controlled trial. Part 1 of RUBY enrolled eligible patients with primary advanced stage III or IV or first recurrent EC who were randomly assigned (1 : 1) to receive either dostarlimab (500 mg) or placebo, plus carboplatin-paclitaxel every 3 weeks for 6 cycles followed by dostarlimab (1000 mg) or placebo every 6 weeks for up to 3 years. OS was a dual primary endpoint. RESULTS: A total of 494 patients were randomized (245 in the dostarlimab arm; 249 in the placebo arm). In the overall population, with 51% maturity, RUBY met the dual primary endpoint for OS at this second interim analysis, with a statistically significant reduction in the risk of death [hazard ratio (HR) = 0.69, 95% confidence interval (CI) 0.54-0.89, P = 0.0020] in patients treated with dostarlimab plus carboplatin-paclitaxel versus carboplatin-paclitaxel alone. The risk of death was lower in the dMMR/MSI-H population (HR = 0.32, 95% CI 0.17-0.63, nominal P = 0.0002) and a trend in favor of dostarlimab was seen in the mismatch repair-proficient/microsatellite stable population (HR = 0.79, 95% CI 0.60-1.04, nominal P = 0.0493). The safety profile for dostarlimab plus carboplatin-paclitaxel was consistent with the first interim analysis. CONCLUSIONS: Dostarlimab in combination with carboplatin-paclitaxel demonstrated a statistically significant and clinically meaningful OS benefit in the overall population of patients with primary advanced or recurrent EC while demonstrating an acceptable safety profile.

Niraparib first-line maintenance therapy in patients with newly diagnosed advanced ovarian cancer: final overall survival results from the PRIMA/ENGOT-OV26/GOG-3012 trial.

BACKGROUND: The phase III PRIMA/ENGOT-OV26/GOG-3012 trial met its primary endpoint. Niraparib first-line maintenance significantly prolonged progression-free survival (PFS) among patients with newly diagnosed advanced ovarian cancer that responded to first-line platinum-based chemotherapy, regardless of homologous recombination deficiency (HRD) status. Final overall survival (OS) results are reported. PATIENTS AND METHODS: Patients were randomized 2:1 to niraparib or placebo, stratified by response to first-line treatment, receipt of neoadjuvant chemotherapy, and tumor HRD status. After reaching 60% target maturity, OS was evaluated via a stratified log-rank test using randomization stratification factors and summarized using Kaplan-Meier methodology. OS testing was hierarchical [overall population first, then the homologous recombination-deficient (HRd) population]. Other secondary outcomes and long-term safety were assessed; an updated, ad hoc analysis of investigator-assessed PFS was also conducted (cut-off date, 8 April 2024). RESULTS: The median follow-up was 73.9 months. In the overall population, the OS hazard ratio was 1.01 [95% confidence interval (CI) 0.84-1.23; P = 0.8834] for niraparib (n = 487) versus placebo (n = 246). In the HRd (n = 373) and homologous recombination-proficient (n = 249) populations, the OS hazard ratios were 0.95 (95% CI 0.70-1.29) and 0.93 (95% CI 0.69-1.26), respectively. Subsequent poly(ADP-ribose) polymerase inhibitor therapy was received by 11.7% and 15.8% of niraparib patients and 37.8% and 48.4% of placebo patients in the overall and HRd populations, respectively. The 5-year PFS rate numerically favored niraparib in the overall (niraparib, 22%; placebo, 12%) and HRd populations (niraparib, 35%; placebo, 16%). Myelodysplastic syndromes/acute myeloid leukemia incidence was <2.5% (niraparib, 2.3%; placebo, 1.6%). No new safety signals were observed. CONCLUSIONS: In patients with newly diagnosed advanced ovarian cancer at high risk of recurrence, there was no difference in OS between treatment arms. In the HRd population, patients alive at 5 years were two times as likely to be progression free with niraparib treatment than placebo. Long-term safety remained consistent with the established niraparib safety profile.

A phase 2 feasibility study of nab-paclitaxel and carboplatin in epithelial carcinoma of the uterus.

BACKGROUND: We evaluated the feasibility of completing 6 cycles of nab-paclitaxel (nab-P) and carboplatin (C) in a single arm prospective clinical trial for advanced/recurrent EC and safety and efficacy of day (D) 1, 8 nab-P in combination with D1 C q3weeks. METHODS: Patients with early-stage, high-risk, advanced primary/recurrent EC without prior platinum/taxane exposure were enrolled in an open-label, single-institution trial (NCT02744898). Patients received 6 cycles of D1 nab-P 100 mg/m2 IV with C AUC 6 IV and D8 nab-P 100 mg/m2 IV q21D. The trial tested the null hypothesis that subjects completing 6 cycles was ≤0.50 versus the alternative that the proportion is ≥0.75 in a single stage design with alpha = 0.05 and power = 80% with 23 subjects. Patients who completed 6 cycles (primary outcome), objective response rate (ORR) and clinical benefit rate (CBR) were estimated with exact 95% Clopper-Pearson confidence intervals. Progression free survival (PFS) and overall survival (OS) were estimated using Kaplan-Meier methods. RESULTS: From 08/2016-03/2018, 23 patients were enrolled. Nineteen patients (82.6%, 95% CI: 61.2%, 95.0%) completed 6 cycles, thus we could reject our null. Twelve patients (52.2%) experienced ≥1 grade 3/4 treatment-related adverse events including: anemia, 6 (26.1%); neutropenia, 5 (21.7%); diarrhea, 3 (13.0%). Fourteen patients (60.1%) reported grade 1 neuropathy. Of 9 patients with measurable target lesions, the ORR was 33.3% (95% CI: 7.5%, 70.1%) and CBR was 55.6% (95% CI: 21.2%, 86.3%). Median PFS in the advanced/recurrent patients was 23.2 (95% CI: 12.1, NR) months. CONCLUSIONS: The nab-P/C D1, 8 regimen met pre-specified feasibility criteria with acceptable toxicity and efficacy. Use of nab-P decreases need for steroid pre-medications, and this carboplatin doublet may prove advantageous for trials assessing combinations with immune checkpoint inhibitors in advanced EC.

BRCA1- and BRCA2-related mutations: therapeutic implications in ovarian cancer.

Ovarian cancer is the deadliest among gynecologic cancers. Hereditary cancer related to BRCA1/2 gene mutations account for ~10%-12% of ovarian cancers. The BRCA1/2 proteins are important in homologous recombination (HR) repair of DNA. Patients with BRCA1/2 mutations have been reported to have improved chemosensitivity to platinum agents, longer disease-free intervals, and longer survivals than nonhereditary counterparts. Recent interest in poly(ADP-ribosyl) polymerase (PARP) proteins which are key components of base excision repair, has led to the development of PARP inhibitors; tumors arising in BRCA1/2 mutation carriers and/or with HR deficiency (HRD) are particularly sensitive to the action of these drugs. As 60%-80% of all advanced ovarian cancers are high-grade serous type, exhibiting HRD in at least 50% (referred as BRCAness) future antitumor strategies may depend on identifying these defects through molecular testing. Once HRD becomes amenable to routine testing, a larger group of ovarian cancer patients than are currently considered for PARP inhibitor trials, may benefit from such targeted therapy.

Phase II study of bevacizumab with liposomal doxorubicin for patients with platinum- and taxane-resistant ovarian cancer.

BACKGROUND: Suppression of neoangiogenesis and pegylated liposomal doxorubicin (PLD) each contribute to the management of platinum-resistant/refractory ovarian cancer. The aim of this study is to test the combination of bevacizumab and PLD in women with resistant or refractory ovarian cancer. METHODS: Eligibility criteria were no more than two prior treatments with platinum-containing regimens and one additional regimen, without anthracyclines. Treatment was administered every 3 weeks (bevacizumab 15 mg/kg beginning on cycle 2 and PLD 30 mg/m(2)). The primary end point was progression-free survival (PFS) at 6 months; the secondary end points included side-effects, overall response rates (ORR) and survival (OS). RESULTS: Forty-six patients were enrolled. The average number of courses administered was 7. The median PFS was 6.6 months (range 1-24.6 months) according to Gynecologic Cancer Intergroup Committee (GCIC) criteria and 7.8 months (range 2-13.3 months) according to Response Evaluation Criteria in Solid Tumors (RECIST). The median OS was 33.2 months (range 3-37.5+ months). The ORR was 30.2% [95% confidence interval (CI) 17.2-46.1] and the clinical benefit rate (CBR) was 86.1% (95% CI 72.1-94.7). Adverse events included mucosal and dermal erosions (30% grade 3) and asymptomatic cardiac dysfunction. Additional toxic effects included hypertension, headache, renal dysfunction and proteinuria, wound healing delay, and one episode each of central nervous system (CNS) ischemia and hemolytic uremic syndrome. CONCLUSION: PLD with bevacizumab has improved activity in recurrent ovarian cancer with increased toxicity.