Thomas J. Herzog

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.

Genomic alterations, molecularly targeted therapy, and survival: a real-world Endometrial Cancer Molecularly Targeted Therapy Consortium cohort study

Next-generation sequencing and tumor testing to direct therapy in advanced/recurrent endometrial cancer are frequently used, but the impact of this approach is unclear. We sought to confirm the proportion of patients with at least 1 actionable alteration and whether the use of molecularly targeted therapy was associated with improved survival in metastatic endometrial cancer. A multidisciplinary consortium was formed to study tumor testing and treatment with targeted therapies in advanced/recurrent endometrial cancer. Tumor testing and therapeutic decisions were physician's recommendations. The abstracted data included age, stage, grade, histology, race, ethnicity, treatment, genomic alterations, protein expression for Her2, p53, mismatch repair, estrogen and progesterone receptors, and survival. Statistical analyses were performed using SAS v9.4. A total of 967 patients from 12 centers were included. The median age was 64 years (range; 22-93 years). Of the participants, 68.5% were White, 24.0% were Black, 2.0% were Asian, and 92.7% were non-Hispanic. A total of 656 (67.8%) patients had recurrent/persistent disease and received a median of two (range; 0-9) therapies. 902 (93.3%) underwent tumor testing. Overall, 576 (94.0%) patients with next-generation sequencing testing had at least 1 genomic alteration in 11 pre-specified genes. The most frequent alterations were PI3K (35.8%), TP53 (34.7%), and PTEN (26.5%) mutations, respectively. A subset of 233 patients received 292 matched biologic therapies, and the median follow-up was 29.7 months, while the median progression-free survival and overall survival were 6.9 and 20.5 months, respectively. The consortium facilitated the development of real-world data on the patterns of genomic testing and molecularly targeted therapy used in a racially and geographically diverse patient cohort with advanced/recurrent endometrial cancer. Survival improved for those receiving matched biologic therapies compared to chemotherapy.

Optimizing disease progression assessment using blinded central independent review and comparing it with investigator assessment in the PRIMA/ENGOT-ov26/GOG-3012 trial: challenges and solutions

Progression-free survival is an established clinically meaningful endpoint in ovarian cancer trials, but it may be susceptible to bias; therefore, blinded independent centralized radiological review is often included in trial designs. We compared blinded independent centralized review and investigator-assessed progressive disease performance in the PRIMA/ENGOT-ov26/GOG-3012 trial examining niraparib monotherapy. PRIMA/ENGOT-ov26/GOG-3012 was a randomized, double-blind phase 3 trial; patients with newly diagnosed stage III/IV ovarian cancer received niraparib or placebo. The primary endpoint was progression-free survival (per Response Evaluation Criteria in Solid Tumors [RECIST] v1.1), determined by two independent radiologists, an arbiter if required, and by blinded central clinician review. Discordance rates between blinded independent centralized review and investigator assessment of progressive disease and non-progressive disease were routinely assessed. To optimize disease assessment, a training intervention was developed for blinded independent centralized radiological reviewers, and RECIST refresher training was provided for investigators. Discordance rates were determined post-intervention. There was a 39% discordance rate between blinded independent centralized review and investigator-assessed progressive disease/non-progressive disease in an initial patient subset (n=80); peritoneal carcinomatosis was the most common source of discordance. All reviewers underwent training, and as a result, changes were implemented, including removal of two original reviewers and identification of 10 best practices for reading imaging data. Post-hoc analysis indicated final discordance rates between blinded independent centralized review and investigator improved to 12% in the overall population. Median progression-free survival and hazard ratios were similar between blinded independent centralized review and investigators in the overall population and across subgroups. PRIMA/ENGOT-ov26/GOG-3012 highlights the need to optimize blinded independent centralized review and investigator concordance using early, specialized, ovarian-cancer-specific radiology training to maximize validity of outcome data.

Validation of comprehensive genomic profiling for prognostic and potential therapeutic molecular classification of endometrial cancer

We sought to validate the prognostic utility of comprehensive genomic profiling (CGP)-based molecular stratification for patients with endometrial carcinoma and to assess co-occurring biomarkers across subtypes. This study included patients from a de-identified nationwide (US-based) endometrial cancer clinicogenomic database who underwent CGP testing as part of routine care. Molecular subtypes were classified as POLE mutated (POLEmut), MSI-H, TP53 mutated (TP53mut), and no specific molecular profile (NSMP). Time to next treatment and overall survival were compared between molecular subtypes, with multivariable Cox models adjusted for relevant covariables. Of 1,139 evaluated patients with advanced or recurrent endometrial carcinoma, the prevalence of the 4 molecular subtypes was 1% POLEmut, 22% high microsatellite instability, 47% TP53mut, and 31% NSMP. Compared with NSMP patients, POLEmut patients had numerically more favorable time to next treatment (HR 0.50, 95% CI 0.21 to 1.21) and overall survival (HR 0.52, 95% CI 0.17 to 1.66). High microsatellite instability patients had similar time to next treatment (HR 1.08, 95% CI 0.89 to 1.30) and overall survival (HR 0.91, 95% CI 0.71 to 1.19) relative to NSMP patients. TP53mut patients had the least favorable outcomes for time to next treatment (compared with NSMP, HR 1.39, 95% CI 1.19 to 1.62) and overall survival (HR 2.15, 95% CI 1.77 to 2.61). In multivariable analysis, TP53mut status was associated with less favorable time to next treatment and overall survival. Frequencies of other biomarkers varied by molecular subtype. The Cancer Genome Atlas (TCGA)/Proactive Molecular Risk Classifier for Endometrial Cancer (ProMisE) molecular classifier for endometrial carcinoma can be recapitulated using CGP and provides prognostic stratification even within an advanced or recurrent disease cohort. CGP for molecular subclassification could support trial design and enrollment and inform treatment escalation or selection.

Ofranergene Obadenovec (Ofra-Vec, VB-111) With Weekly Paclitaxel for Platinum-Resistant Ovarian Cancer: Randomized Controlled Phase III Trial (OVAL Study/GOG 3018)

PURPOSE To evaluate the addition of ofranergene obadenovec (ofra-vec, VB-111), a novel gene-based anticancer targeted therapy, to once a week paclitaxel in patients with recurrent platinum-resistant ovarian cancer (PROC). METHODS This placebo-controlled, double-blind, phase III trial (ClinicalTrials.gov identifier: NCT03398655 ) randomly assigned patients with PROC 1:1 to receive intravenous ofra-vec every 8 weeks with once a week IV paclitaxel or placebo with paclitaxel until disease progression. The dual primary end points were overall survival (OS) and progression-free survival (PFS) as assessed by Blinded Independent Central Review. RESULTS Between December 2017 and March 2022, 409 patients were randomly assigned. The median PFS was 5.29 months in the ofra-vec arm and 5.36 months in the control arm, hazard ratio (HR) 1.03 (CI, 0.83 to 1.29; P = .7823). The median OS with ofra-vec was 13.37 months versus 13.14 months, HR 0.97 (CI, 0.75 to 1.27; P = .8440). Objective response rates (ORRs) per RECIST 1.1 were similar in both arms: 28.9% with ofra-vec versus 29.6% with control. In both treatment arms, response to CA-125 was a substantial prognostic factor for both PFS and OS. In the ofra-vec arm, the HR in CA-125 responders compared with that in nonresponders for PFS was 0.2428 (CI, 0.1642 to 0.3588), and for OS, the HR was 0.3343 (CI, 0.2134 to 0.5238). Safety profile was characterized by common transient flu–like symptoms such as fever and chills. CONCLUSION The addition of ofra-vec to paclitaxel did not improve PFS or OS. The PFS and ORR in the control arm exceeded the results that were anticipated on the basis of the AURELIA chemotherapy control arm. CA-125 response was a substantial prognostic biomarker for PFS and OS in patients with PROC treated with paclitaxel.