A Study of Avutometinib (VS-6766) v. Avutometinib (VS-6766) + Defactinib in Recurrent Low-Grade Serous Ovarian Cancer With and Without a KRAS Mutation

Efficacy and Safety of Avutometinib ± Defactinib in Recurrent Low-Grade Serous Ovarian Cancer: Primary Analysis of ENGOT-OV60/GOG-3052/RAMP 201

PURPOSE This study evaluated the efficacy and safety of avutometinib (rapidly accelerated fibrosarcoma/mitogen-activated extracellular signal-regulated kinase [MEK] clamp) alone or in combination with defactinib (focal adhesion kinase inhibitor) in patients with recurrent low-grade serous ovarian cancer (LGSOC). METHODS In this phase II, open-label study, patients with recurrent, measurable LGSOC after ≥1 line of platinum chemotherapy were stratified by tumor Kirsten rat sarcoma virus homolog ( KRAS ) mutation status and randomly assigned to oral avutometinib 4.0 mg two times per week monotherapy or avutometinib 3.2 mg two times per week in combination with oral defactinib 200 mg two times per day. The combination was selected as the go-forward regimen for expansion. The primary end point was objective response rate (ORR) by blinded independent central review. RESULTS A total of 115 patients received the go-forward combination regimen. Patients had a median of 3 (range, 1-9) prior lines of therapy, including hormonal (86%), bevacizumab (51%), and MEK inhibitor (22%). Confirmed ORR was 31% (95% CI, 23% to 41%) with a median duration of response of 31.1 months (95% CI, 14.8 to 31.1). ORR was 44% in KRAS- mutant and 17% in KRAS wild-type cohorts. The median progression-free survival was 12.9 months (95% CI, 10.9 to 20.2) overall and 22.0 months (95% CI, 11.1 to 36.6) and 12.8 months (95% CI, 7.4 to 18.4) in KRAS- mutant and wild-type cohorts, respectively. The most frequent grade ≥3 treatment-related adverse events (AEs) were elevated creatine phosphokinase (24%), diarrhea (8%), and anemia (5%). Ten percent of patients discontinued because of AEs. CONCLUSION The efficacy and safety profile of avutometinib in combination with defactinib support this combination as a potential standard of care for recurrent LGSOC. A randomized phase 3 study of avutometinib and defactinib versus investigator's choice of therapy for women with recurrent LGSOC is currently enrolling (RAMP301; ClinicalTrials.gov identifier: NCT06072781 ).

Preclinical efficacy of RAF/MEK clamp avutometinib in combination with FAK inhibition in low grade serous ovarian cancer

Low-grade-serous-ovarian-carcinoma (LGSOC) is characterized by a high recurrence rate and limited therapeutic options. About one-third of LGSOC contains mutations in MAPK pathway genes such as KRAS/NRAS/BRAF. Avutometinib is a dual RAF/MEK inhibitor while defactinib and VS-4718 are focal-adhesion-kinase-inhibitors (FAKi). We determined the preclinical efficacy of avutometinib±VS-4718 in LGSOC patient-derived-tumor-xenografts (PDX). Whole-exome-sequencing (WES) was used to evaluate the genetic fingerprint of 3 patient-derived LGSOC (OVA(K)250, PERIT(M)17 and A(PE)148). OVA(K)250 tissue was successfully xenografted as PDX into female CB17/lcrHsd-Prkdc/SCID-mice. Animals were treated with either control, avutometinib, VS-4718, or avutometinib/ VS-4718 once daily five days on and two days off through oral gavage. Mechanistic studies were performed ex vivo using avutometinib±defactinib treated LGSOC tumor samples by western blot. WES results demonstrated wild-type KRAS in all 3 LGSOC. OVA(K)250 PDX showed gain-of-function mutations (GOF) in PTK2 and PTK2B genes, and loss-of-heterozygosity in ADRB2, potentially sensitizing to FAK and RAF/MEK inhibition. The combination of avutometinib/ VS-4718 demonstrated strong tumor-growth inhibition compared to controls starting at day 9 (p < 0.002) in OVA(K)250PDX. By 60 days, mice treated with avutometinib alone and avutometinib/VS-4718 were still alive; compared to median survival of 20 days in control-treated mice and of 35 days in VS-4718-treated mice (p < 0.0001). By western-blot assays exposure of OVA(K)250 to avutometinib, FAKi defactinib and their combination demonstrated decreased phosphorylated FAK (p-FAK) as well as decreased p-ERK. Avutometinib, and to a larger extent its combination with FAK inhibitor VS-4718, demonstrated promising in vivo activity against a KRAS wild-type LGSOC-PDX. These data support the ongoing registration-directed study (RAMP201/NCT04625270).

Alessandro D. Santin

Ana Oaknin

Dr. Ana Oaknin is the Head of the Gynaecological Cancer Programme at the Vall d’Hebron Institute of Oncology (VHIO) in Barcelona, Spain and a prominent figure in the field of Gynaecological Oncology, internationally. Dr. Oaknin is an active faculty member of the European Society of Medical Oncology (ESMO) Gynaecologic Track. She has served as Scientific Commit Member for ESMO Meeting in the last few years, as Subject Editor for Gynaecologic Malignancies Guidelines (2022-2024)and she is chair of the ESMO gynaecological cancer congress (2024-2026). Dr. Oaknin has been the Gynaecologic Cancer Intergroup (GCIG) Cervical Cancer Committee Chair from 2022-2224 and is an active member of American Society of Clinical Oncology (ASCO), Society of Gynaecologic Oncology (SGO) where she serves as International Member on the Board Committee. Dr. Oaknin obtained her degree in Medicine and Surgery from the Complutense University of Madrid in 1994 and specialized in Medical Oncology at the Hospital Universitario de la Princesa, Universidad Complutense de Madrid, becoming board certified in 2000. She earned her PhD Cum Laude from the Universidad Autónoma de Barcelona in 2016. Throughout her career, Dr Oaknin has been primarily focused on clinical research, serving as the principal investigator for numerous Phase I, II, and III studies, both nationally and internationally. She is the author of many outstanding articles in high impact journals.

Bradley J. Monk

Charlie Gourley

Christine Gennigens

David M. O'Malley

Emily Prendergast

Kathleen N. Moore

Manuel Rodrigues

Nicoletta Colombo

Premal H. Thaker

Robert W Holloway

Susana Banerjee

Toon Van Gorp

Véronique D’Hondt