Letrozole plus anlotinib as a chemotherapy-free regimen for ER-positive platinum-resistant recurrent epithelial ovarian cancer patients following second-line platinum-based chemotherapy failure: A prospective, single-arm, open-label, phase II study.

OBJECTIVE

Estrogen receptor-positive (ER-positive) platinum-resistant recurrent epithelial ovarian cancer (PROC) patients following second-line platinum-based chemotherapy failure face the dilemma of limited therapeutic options. We aimed to evaluate the efficacy and safety of letrozole plus anlotinib for these patients.

METHODS

We conducted a single-arm phase 2 study (NCT04720807) evaluating letrozole plus anlotinib in ER-positive PROC patients following second-line platinum-based chemotherapy failure. Patients received oral anlotinib 10 mg daily (days 1-14, q21d) and continuous oral letrozole 2.5 mg. Treatment was continued until disease progression, death, intolerant toxicity, or patient withdrawal. The primary endpoint was the objective response rate (ORR) according to RECIST version 1·1 and the GCIG criteria.

RESULTS

Between January 2021 and December 2023, 30 patients were assessed for eligibility, and 27 patients were enrolled. The median age was 62 years (range 50-79). Seven patients achieved a partial response, while no patients showed a complete response, resulting in an ORR of 25·9 % (95 % CI, 11·8 %-46·6 %). The disease control rate was 74·1 % (95 % CI, 53·4 %-88·1 %). The median progression-free survival was 4·57 months (95 % CI, 4·07-9·66). Most adverse events were Grade 1-2 and manageable. Patients with a primary platinum-free interval exceeding 6 months, lower baseline CA-125 levels (<500 IU), or higher ER expression levels (≥ 25 % stained positive for ER) showed a statistically significant treatment benefit.

CONCLUSION

The combination of letrozole plus anlotinib demonstrated promising efficacy and manageable toxicity in the treatment of ER-positive PROC patients following second-line platinum-based chemotherapy failure.