The Food and Drug Administration (FDA) has approved pembrolizumab as well as pembrolizumab and berahyaluronidase alfa-pmph in combination with paclitaxel, with or without bevacizumab, for adult patients with platinum-resistant epithelial ovarian, fallopian tube, or primary peritoneal carcinoma whose tumours express PD-L1 (CPS≥1) as determined by an FDA-authorized test, and who have received one or two prior systemic treatment regimens.

FDA also approved the PD-L1 IHC 22C3 pharmDx as a companion diagnostic device to identify patients with epithelial ovarian, fallopian tube, or primary peritoneal carcinoma whose tumours express PD-L1 (CPS≥1) for treatment with pembrolizumab.

Efficacy and safety

Efficacy was evaluated in KEYNOTE-B96 (NCT05116189), a multicenter, randomised, double-blind, placebo-controlled trial that enroled 643 patients with platinum-resistant, epithelial ovarian, fallopian tube, or primary peritoneal carcinoma who received one or two prior lines of systemic therapy for ovarian carcinoma.

Patients must have received at least one line of platinum-based chemotherapy for ovarian cancer with radiographic evidence of disease progression within six months after the last dose.

Patients were randomised (1:1) to either pembrolizumab plus paclitaxel with or without bevacizumab or placebo plus paclitaxel with or without bevacizumab.

The major efficacy outcome measure was progression-free survival (PFS) as assessed by the investigator according to RECIST v1.1. An additional efficacy outcome measure was overall survival (OS).

Among the 466 patients with tumours expressing PD-L1 with CPS ≥ 1, median PFS was 8.3 months (95% CI: 7.0, 9.4) in the pembrolizumab arm and 7.2 months (95% CI: 6.2, 8.1) in the placebo arm (Hazard Ratio [HR] 0.72 [95% CI: 0.58, 0.89]; p-value 0.0014).

Median OS was 18.2 months (95% CI: 15.3, 21.0) in the pembrolizumab arm and 14.0 months (95% CI: 12.5, 16.1) in the placebo arm (HR 0.76 [95% CI: 0.61, 0.94]; p-value 0.0053).

The overall safety profile of pembrolizumab in combination with paclitaxel, with or without bevacizumab in KEYNOTE-B96 was similar to that observed in prior trials in cancer.

The prescribing information includes warnings and precautions for immune-mediated adverse reactions, infusion-related reactions, complications of allogeneic haematopoietic stem cell transplantation, and embryo-fetal toxicity.

Recommended dosage

The recommended dose of pembrolizumab is 200 mg every three weeks or 400 mg every six weeks until disease progression, unacceptable toxicity, or up to 24 months.

The recommended dose of pembrolizumab and berahyaluronidase alfa-pmph is 395mg/4,800 units every three weeks or 790mg/9,600 units every six weeks until disease progression, unacceptable toxicity, or up to 24 months.

Administer pembrolizumab or pembrolizumab and berahyaluronidase alfa-pmph prior to paclitaxel with or without bevacizumab when given on the same day.

Refer to the prescribing information for the agents administered in combination with pembrolizumab for recommended dosing information.

Source: FDA