FDA approves new immunotherapy for some epithelial ovarian cancers
The U.S. Food and Drug Administration (FDA) has approved the immunotherapy drug Keytruda (pembrolizumab), in combination with chemotherapy, for certain patients with platinum-resistant epithelial ovarian, fallopian tube, or primary peritoneal cancers whose tumours express a biomarker called PD-L1. The decision follows positive results from the Phase 3 KEYNOTE-B96 clinical trial and was conducted in collaboration with Australia’s Therapeutic Goods Administration (TGA).
Reading time: 5 minutes
Image: CDC
The challenge of platinum-resistant ovarian cancer
Most people diagnosed with ovarian cancer initially receive platinum-based chemotherapy. While many respond well at first, disease recurrence and chemotherapy resistance is common. If the cancer returns within six months of completing platinum-based chemotherapy, it is considered “platinum resistant”.
When ovarian cancer becomes platinum-resistant, there are fewer effective treatment options available. Researchers have been working hard to find new approaches for this group of patients. While immunotherapy has not previously shown strong benefit for ovarian cancer overall, newer research suggests that carefully selecting patients based on tumour biology may help identify those most likely to benefit.
How does Keytruda work?
Keytruda (pembrolizumab) is a type of immunotherapy known as a PD-1 inhibitor. It works by blocking the PD-1 protein, helping the immune system better recognise and attack cancer cells.
The approval was based on results from the Phase 3 KEYNOTE-B96 clinical trial. The study evaluated pembrolizumab in combination with weekly paclitaxel (Taxol-based chemotherapy), with or without Avastin (bevacizumab), in individuals with platinum-resistant ovarian cancer.
What did the clinical trial show?
In patients whose tumours expressed certain levels of PD-L1 (a biomarker measured in tumours):
- The relative risk of cancer progression was reduced by 28%
- The relative risk of death was reduced by 24%
- Median progression-free survival improved from 7.2 to 8.3 months
- Median overall survival improved from 14 months to 18.2 months
While these gains may appear modest, in platinum-resistant ovarian cancer even a few additional months of survival is meaningful.
Previous trials of immunotherapy in ovarian cancer have not shown this degree of benefit. In the KEYNOTE-B96 study, the strongest results were seen in patients whose tumours tested positive for PD-L1. As a result, treatment eligibility requires PD-L1 to be present in these cancers.
An FDA-approved companion diagnostic test (PD-L1 IHC 22C3 pharmDx) is used to measure PD-L1 levels in tumour tissue and help identify patients who are most likely to benefit. This marks the first immunotherapy companion diagnostic approved specifically for ovarian cancer.
Image: CDC
A step towards more personalised treatment for epithelial ovarian cancers
Approximately one in four epithelial ovarian cancers will develop platinum-resistant disease within six months of treatment. Once resistance occurs, options are limited.
This new approval suggests that a biomarker-selected group of patients may benefit from immunotherapy as part of their treatment plan. It represents a large step toward more personalised care, where treatment decisions are guided by tumour biology rather than a one-size-fits-all approach.
What this means for Australia
The FDA review in the US was conducted in collaboration with Australia’s Therapeutic Goods Administration (TGA). However, regulatory approval does not automatically translate to easy and subsidised access.
For medicines to be publicly funded in Australia, they must be listed on the Pharmaceutical Benefits Scheme (PBS). Encouragingly, the Pharmaceutical Benefits Advisory Committee (PBAC) has recommended broader multi-cancer PBS listings for pembrolizumab in advanced cancers.
If implemented, eligible Australian patients may be able to access pembrolizumab at the standard PBS co-payment ($25 for non-concession), rather than the significantly higher private cost (close to $8,000).
If you or a loved one would like to understand whether this treatment may be relevant, speak with your treating specialist.
They can provide advice based on your individual diagnosis, tumour biology, and treatment history.
- Colombo N, Zsiros E, Sebastianelli A, et al. Pembrolizumab vs placebo plus weekly paclitaxel ± bevacizumab in platinum-resistant recurrent ovarian cancer: results from the randomized double-blind phase III ENGOT-ov65/KEYNOTE-B96 study. Presented at: 50th European Society for Medical Oncology Congress; October 17-21, 2025; Berlin, Germany. Abstract LBA3.
- U.S. Food and Drug Administration (FDA) (2026), FDA approves pembrolizumab with paclitaxel for platinum-resistant epithelial ovarian, fallopian tube, or primary peritoneal carcinoma, https://www.fda.gov/drugs/resources-information-approved-drugs/fda-approves-pembrolizumab-paclitaxel-platinum-resistant-epithelial-ovarian-fallopian-tube-or, accessed 16 February 2026.
- FDA Approves Pembrolizumab Combo for Platinum-Resistant Ovarian Cancer, Oncology News Central, https://www.oncologynewscentral.com/drugs/info/fda-approves-pembrolizumab-combo-for-platinum-resistant-ovarian-cancer, accessed 16 February 2026.
Related OCRF articles
Get the latest news, stories & updates.
