Is Keytruda (pembrolizumab) used to treat ovarian cancer?

Keytruda (Pembrolizumab) for Ovarian Cancer

Keytruda (pembrolizumab) is not FDA-approved specifically for ovarian cancer treatment and is not considered a standard therapy for this malignancy according to current NCCN guidelines.

Current Status of Immunotherapy in Ovarian Cancer

According to the NCCN Guidelines for Ovarian Cancer, the standard treatments for ovarian cancer primarily include:

1. Surgery (debulking)
2. Platinum-based chemotherapy regimens
3. Bevacizumab (an anti-angiogenic agent)
4. PARP inhibitors (olaparib, niraparib, rucaparib) for specific genetic subtypes 1

The 2021 NCCN Guidelines clearly outline FDA-approved indications for ovarian cancer treatment, and pembrolizumab (Keytruda) is notably absent from these recommendations 1. The guidelines provide a comprehensive table of approved agents including bevacizumab and various PARP inhibitors, but do not include pembrolizumab as a standard treatment option.

Emerging Research on Pembrolizumab in Ovarian Cancer

While not FDA-approved for ovarian cancer, pembrolizumab has been investigated in clinical trials:

• A phase 2 trial combining pembrolizumab with bevacizumab and oral cyclophosphamide in heavily pretreated recurrent ovarian cancer showed an objective response rate of 47.5% and progression-free survival of 10 months 2

• Another study of the same combination demonstrated a 13% response rate in heavily pretreated platinum-resistant patients 3

• An exceptional case response was reported in a patient with PD-L1 genetic rearrangement, suggesting potential benefit in specific molecular subtypes 4

Biomarker-Based Considerations

Pembrolizumab may have utility in specific biomarker-defined subsets of ovarian cancer:

• Tumors with microsatellite instability-high (MSI-H) or deficient mismatch repair (dMMR)
• Tumors with high tumor mutational burden (TMB-H)

These biomarker-based indications are tumor-agnostic approvals that could potentially include ovarian cancer patients whose tumors display these characteristics, though this represents a small subset of ovarian cancer cases.

Current Standard of Care for Ovarian Cancer

The 2024 NCCN guidelines emphasize that the standard treatments for ovarian cancer include:

1. Optimal surgical debulking (particularly important for low-grade serous, mucinous, and clear cell subtypes due to their lower chemosensitivity) 1

2. Platinum-based chemotherapy (typically carboplatin/paclitaxel) 1

3. Maintenance therapy with:

   • Bevacizumab
   • PARP inhibitors (olaparib, niraparib, rucaparib) for appropriate patients 1

Conclusion

For patients with ovarian cancer seeking treatment options, the current evidence does not support the routine use of Keytruda (pembrolizumab). Standard therapies with proven efficacy and survival benefit should be prioritized according to NCCN guidelines. Patients interested in immunotherapy should consider clinical trials or discuss with their oncologist whether they have specific biomarker profiles (MSI-H/dMMR or TMB-H) that might make them candidates for pembrolizumab under its tumor-agnostic approvals.