Larry J. Copeland

Phase II Trial of Ribociclib Plus Letrozole in Women With Recurrent Low-Grade Serous Carcinoma of the Ovary, Fallopian Tube, or Peritoneum: A GOG Partners Trial (GOG 3026)

PURPOSE Low-grade serous carcinoma (LGSOC) of the ovary, fallopian tube, or peritoneum is a hormonally driven, relatively chemoresistant malignancy with limited treatment options in the recurrent setting. Given frequent estrogen receptor (ER) expression and dysregulation of the cyclin-dependent kinases 4 and 6 (CDK4/6)–p16–Rb pathway, features shared with hormone receptor–positive breast cancer, dual endocrine, and CDK4/6 inhibition is a biologically rational strategy. This phase II trial evaluated ribociclib plus letrozole in recurrent LGSOC. METHODS This open-label, single-arm, multicenter phase II study enrolled women with measurable, recurrent LGSOC. Patients received ribociclib (600 mg orally, once daily, days 1-21 of a 28-day cycle) and letrozole (2.5 mg orally, once daily). The primary end point was investigator-assessed objective response rate (ORR) per RECIST 1.1. Secondary end points included clinical benefit rate (CBR), progression-free survival (PFS), overall survival (OS), and safety. RESULTS Of 74 patients screened, 51 were enrolled and 49 treated. The confirmed ORR was 30.6% (90% CI, 19.9 to 43.2), including one complete and 14 partial responses. Among responders, the median duration of response was 21.2 months. The CBR was 84% (90% CI, 72.5 to 91.6). The median PFS was 14.5 months (90% CI, 10.1 to 28.8), and the median OS was 44.5 months (90% CI, 31.8 to not reached). The most common grade ≥3 adverse event (AE) was neutropenia (47%), managed with dose modifications. Three grade 5 events (6%) occurred but were unrelated to treatment. Treatment discontinuation because of AEs occurred in 4%. No dose-limiting toxicities were observed. CONCLUSION Ribociclib plus letrozole met the primary end point, achieving meaningful response rates and durable disease control in recurrent LGSOC. The safety profile was consistent with prior CDK4/6 inhibitor studies. This combination represents a therapeutic option in this rare and genomically distinct subtype.

Identification of Patients With Ovarian Cancer Experiencing the Highest Benefit From Bevacizumab in the First-Line Setting on the Basis of Their Tumor-Intrinsic Chemosensitivity (KELIM): The GOG-0218 Validation Study

PURPOSE In patients with high-grade ovarian cancer, predictors of bevacizumab efficacy in first-line setting are needed. In the ICON-7 trial, a poor tumor intrinsic chemosensitivity (defined by unfavorable modeled cancer antigen-125 [CA-125] ELIMination rate constant K [KELIM] score) was a predictive biomarker. Only the patients with high-risk disease (suboptimally resected stage III, or stage IV) exhibiting unfavorable KELIM score < 1.0 had overall survival (OS) benefit from bevacizumab (median: 29.7 v 20.6 months; hazard ratio [HR], 0.78). An external validation study in the GOG-0218 trial was performed. METHODS In GOG-0218, 1,873 patients were treated with carboplatin-paclitaxel ± concurrent-maintenance bevacizumab/placebo. Patient KELIM values were calculated with CA-125 kinetics during the first 100 chemotherapy days by the Lyon University team. The association between KELIM score (favorable ≥ 1.0, or unfavorable < 1.0) and bevacizumab benefit for progression-free survival (PFS)/OS was independently assessed by NGR-GOG using univariate/multivariate analyses. RESULTS KELIM was assessable in 1,662 patients with ≥ 3 CA-125 available values. An unfavorable KELIM score was associated with bevacizumab benefit compared with placebo (PFS: HR, 0.70; 95% CI, 0.59 to 0.82; OS: HR, 0.87; 95% CI, 0.73 to 1.03), whereas a favorable KELIM was not (PFS: HR, 0.96; 95% CI, 0.79 to 1.17; OS: HR, 1.11; 95% CI, 0.89 to 1.39). The highest benefit was observed in patients with a high-risk disease exhibiting unfavorable KELIM, for PFS (median: 9.1 v 5.6 months; HR, 0.64; 95% CI, 0.53 to 0.78), and for OS (median: 35.1 v 29.1 months; HR, 0.79; 95% CI, 0.65 to 0.97). CONCLUSION This GOG-0218 trial investigation validates ICON-7 findings about the association between poor tumor chemosensitivity and benefit from concurrent-maintenance bevacizumab, suggesting that bevacizumab may mainly be effective in patients with poorly chemosensitive disease. Bevacizumab may be prioritized in patients with a high-risk and poorly chemosensitive disease to improve their PFS/OS (patient KELIM score calculator available on the Biomarker Kinetics website).

Randomized Phase III Trial of Paclitaxel and Carboplatin Versus Paclitaxel and Ifosfamide in Patients With Carcinosarcoma of the Uterus or Ovary: An NRG Oncology Trial

PURPOSE This phase III randomized trial ( NCT00954174 ) tested the null hypothesis that paclitaxel and carboplatin (PC) is inferior to paclitaxel and ifosfamide (PI) for treating uterine carcinosarcoma (UCS). PATIENTS AND METHODS Adults with chemotherapy-naïve UCS or ovarian carcinosarcoma (OCS) were randomly assigned to PC or PI with 3-week cycles for 6-10 cycles. With 264 events in patients with UCS, the power for an overall survival (OS) hybrid noninferiority design was 80% for a null hazard ratio (HR) of 1.2 against a 13% greater death rate on PI with a type I error of 5% for a one-tailed test. RESULTS The study enrolled 536 patients with UCS and 101 patients with OCS, with 449 and 90 eligible, respectively. Primary analysis was on patients with UCS, distributed as follows: 40% stage I, 6% stage II, 31% stage III, 15% stage IV, and 8% recurrent. Among eligible patients with UCS, PC was assigned to 228 and PI to 221. PC was not inferior to PI. The median OS was 37 versus 29 months (HR = 0.87; 90% CI, 0.70 to 1.075; P < .01 for noninferiority, P > .1 for superiority). The median progression-free survival was 16 versus 12 months (HR = 0.73; P = < 0.01 for noninferiority, P < .01 for superiority). Toxicities were similar, except that more patients in the PC arm had hematologic toxicity and more patients in the PI arm had confusion and genitourinary hemorrhage. Among 90 eligible patients with OCS, those in the PC arm had longer OS (30 v 25 months) and progression-free survival (15 v 10 months) than those in the PI arm, but with limited precision, these differences were not statistically significant. CONCLUSION PC was not inferior to the active regimen PI and should be standard treatment for UCS.

Tumor Treating Fields therapy in platinum-resistant ovarian cancer: Results of the ENGOT-ov50/GOG-3029/INNOVATE-3 pivotal phase 3 randomized study

Tumor Treating Fields (TTFields) are electric fields that disrupt processes critical for cancer cell viability and tumor progression. The pivotal, phase 3 ENGOT-ov50/GOG-3029/INNOVATE-3 study evaluated efficacy and safety of TTFields therapy with paclitaxel (PTX) vs PTX in patients with platinum-resistant ovarian cancer (PROC). Adult patients with PROC with ≤ 5 total prior lines of therapy (LOT), including ≤ 2 prior LOT for platinum-resistant disease, and ECOG PS of 0-1 were randomized 1:1 to receive TTFields (200 kHz; ≥ 18 h/day) + PTX (80 mg/m Between March 2019 and November 2021, 558 patients (ECOG PS 0, 60.2 %; median [range] age, 62 [22-91] years) were assigned TTFields+PTX (n = 280) or PTX (n = 278). 24.4 % had 4 + prior LOT. Median OS was 12.2 months with TTFields+PTX vs 11.9 months with PTX (HR, 1.01; 95 % CI, 0.83-1.24; p = 0.89). Grade ≥ 3 adverse events (AEs) were similar between treatment groups. Grade 1/2 device-related skin AEs occurred in 83.6 % of patients receiving TTFields therapy. In exploratory post-hoc analysis in PLD-naive patients, median OS was 16 months with TTFields+PTX (n = 113) vs 11.7 months with PTX (n = 88; nominal HR, 0.67; 95 % CI, 0.49-0.94; p = 0.03). No new safety signals were identified. TTFields+PTX did not significantly improve OS compared with PTX in the intent-to-treat population. An exploratory post-hoc analysis suggests a potentially favorable benefit-risk profile for TTFields therapy in PLD-naive patients.

Paclitaxel and Carboplatin or Ifosfamide in Treating Patients With Newly Diagnosed, Persistent or Recurrent Uterine, Ovarian, Fallopian Tube, or Peritoneal Cavity Cancer

This randomized phase III trial studies paclitaxel and carboplatin see how well they work compared with paclitaxel and ifosfamide in treating patients with fallopian tube, or peritoneal cavity cancer that is newly diagnosed, persistent, or has come back (recurrent). Drugs used in chemotherapy, such as paclitaxel, carboplatin, and ifosfamide, work in different ways to stop the growth of tumor cells, either by killing the cells, by stopping them from dividing, or by stopping them from spreading. It is not yet known whether paclitaxel is more effective when given with carboplatin or ifosfamide in treating patients with uterine, ovarian, fallopian tube, or peritoneal cavity cancer.

Carboplatin and Paclitaxel With or Without Bevacizumab in Treating Patients With Stage III or Stage IV Ovarian Epithelial, Primary Peritoneal, or Fallopian Tube Cancer

This randomized phase III trial studies carboplatin, paclitaxel, and bevacizumab to see how well they work compared to carboplatin, paclitaxel, and placebo in treating patients with stage III or stage IV ovarian epithelial, primary peritoneal, or fallopian tube cancer. Drugs used in chemotherapy, such as carboplatin and paclitaxel, work in different ways to stop the growth of tumor cells, either by killing the cells or by stopping them from dividing. Monoclonal antibodies, such as bevacizumab, may interfere with the ability of tumor cells to grow and spread. It is not yet known whether carboplatin, paclitaxel, and bevacizumab are more effective than carboplatin, paclitaxel, and placebo in treating ovarian epithelial, primary peritoneal, or fallopian tube cancer.