According to results from the phase 3 AXLerate-OC (GOG-3059/ENGOT OV-66) trial, the addition of batiraxcept, an Fc-fusion protein which sequesters GAS6 and inhibitors its interaction with AXL, to paclitaxel did not improve progression-free survival (PFS) or overall survival (OS) among patients with platinum-resistant recurrent ovarian cancer. However, patients with AXL high expression demonstrated a statistically significant improvement in PFS and OS with the combination.

These results were first presented by Katherine C. Fuh, MD, PhD, University of California, San Francisco, California, at the 2024 American Society of Clinical Oncology Annual Meeting in Chicago, Illinois.

This global, placebo-controlled, double-blinded phase 3 trial enrolled 366 patients with platinum-resistant ovarian cancer. Patients were randomized on a 1-to-1 basis to receive either intravenous batiraxcept once every 2 weeks plus paclitaxel once a week, or placebo plus paclitaxel. The primary end point of this trial was progression-free survival as assessed by a investigator, with overall survival as a secondary end point.

The median PFS was 5.13 months in the batiraxcept arm and 5.49 months in the control arm (hazard ratio [HR], 1.29; P = .98). The median OS was 14.29 months and 14.39 months respectively (HR, 1.06; P = .64). According to an exploratory analysis of 304 evaluable tumors, 20% had high AXL expression, by immunohistochemistry. Among those patients with high AXL expression, the median PFS was 5.78 in the batiraxcept arm vs 3.71 months in the control arm (HR, 0.55; P = .042), and the median OS was 17.8 months vs 8.11 months, respectively (HR, 0.32; P = .006). There were no safety concerns for batiraxcept in combination with paclitaxel.

While the PFS and OS were similar in both arms among the overall cohort, Dr Fuh concluded, “in the exploratory AXL high cohort, we found that patients demonstrated statistically significant improvements in PFS and OS [with the batiraxcept-paclitaxel combination].” She added, “AXL expression as a biomarker can be considered for further development to identify patients who can benefit from AXL targeted treatment.”

Source:

Fuh KC, Tsitsishvili Z, Reid TJ, et al. AXLerate-OC/GOG-3059/ENGOT OV-66: Results of a phase 3, randomized, double-blind, placebo/paclitaxel-controlled study of batiraxcept (AVB-S6-500) in combination with paclitaxel in patients with platinum-resistant recurrent ovarian cancer. Presented at 2024 ASCO Annual Meeting. May 31-June 4, 2024; Chicago, Illinois. Abstract #LBA5515