MSD has reported that the randomised Phase III KEYNOTE-B96 trial of Keytruda (pembrolizumab) plus chemotherapy (paclitaxel), with or without bevacizumab, has met its primary goal of progression-free survival (PFS) in individuals with platinum-resistant recurrent ovarian cancer.
Also referred to as ENGOT-ov65, this ongoing, double-blind trial is intended for individuals with this cancer, whose tumours express programmed death-ligand 1 (PD-L1), and all-comers.
A secondary endpoint of overall survival (OS) was also met in patients with PD-L1-positive tumours.
The Independent Data Monitoring Committee's pre-specified interim analyses revealed an improvement in PFS when the Keytruda-based regimen was used across all patients, regardless of PD-L1 expression.
It was tested against a placebo group receiving chemotherapy with or without bevacizumab.
In addition to PFS, the trial demonstrated a meaningful OS improvement for those with PD-L1-expressing tumours, as defined by a Combined Positive Score (CPS) of one or higher.
Keytruda’s safety profile during the trial aligned with previous studies, without any safety concerns observed.
The trial, sponsored by the company and carried out in partnership with the European Network for Gynaecologic Oncology Trial (ENGOT) groups, compared Keytruda and chemotherapy against a placebo with chemotherapy.
It enrolled approximately 643 subjects, who were randomised and given either 400mg intravenous Keytruda every six weeks for two years, alongside paclitaxel with or without bevacizumab, or a placebo plus paclitaxel with or without bevacizumab.
An anti-programmed death receptor-1 (PD-1), Keytruda, works by enhancing the immune system's ability to identify and combat tumour cells.
This humanised monoclonal antibody inhibits the interaction between PD-1 and its ligands, PD-L1 and PD-L2, thus activating T-lymphocytes, which may impact both tumour and healthy cells.
MSD Research Laboratories global clinical development vice-president Dr Gursel Aktan said: “This marks the first time a Keytruda-based regimen has shown the ability to help certain patients with platinum-resistant ovarian cancer live longer, and the first time an immune checkpoint inhibitor-based regimen has demonstrated an OS benefit in ovarian cancer.”
Last November, MSD reported positive topline outcomes from the Phase III MK-3475A-D77 study, assessing the non-inferiority of subcutaneous Keytruda administration, with chemotherapy, as a first-line treatment for individuals with metastatic non-small cell lung cancer.
