1131P - A phase II study of pembrolizumab combination with temozolomide as 1L treatment for Chinese metastatic acral melanoma patients

Background

Acral melanomas are rare melanoma subtypes with poor prognosis and show limited response to the standard of care for the first line treatment of advanced melanoma (Dacarbazine). In this study, we evaluate the efficacy of the novel combination of pembrolizumab and temozolomide as the first line treatment in Chinese treatment-naïve metastatic acral melanoma patients.

Methods

This was a single arm, open-label, phase II study (ChiCTR2100050073). Eligible patients aged ≥18 years with histopathologically confirmed metastatic acral melanoma (stage III/IV) were enrolled. Patients received pembrolizumab 200 mg Q3W up to 35 cycles (approximately 2 years), and temozolomide 150mg/m²/d on days 1-5 every 4 weeks. For patients who have completed the first treatment cycle without developing dose-limiting toxicity (DLT), Temozolomide would then be administered as 200mg/m²/d on days 1-5, for up to 8 cycles. The primary endpoint was objective response rate (ORR) per RECIST 1.1 by investigator review. Secondary end points were duration of response (DOR), disease control rate (DCR), progression-free survival (PFS), overall survival (OS) and safety.

Results

A total of 38 patients were enrolled. The median age was 58 years (27-71 years), and 23 patients (60.5%) were male. At the data cut-off Apr 10, 2024, 35 patients have received at least one post-treatment radiological evaluation. The ORR was 37.1% (1 CR; 12 PR [95% CI: 21.5% - 55.1%]), 3 unconfirmed PR was included. The median DOR was 7.7 months (95% CI: 5.0-Not reached [NR]). The DCR was 80.0% (1 CR; 12 PR;15 SD [95% CI: 63.1-91.6%]). The median PFS was 7.7 months (95% CI: 4.9-13.2 months). The median OS was NR. No unexpected treatment-related adverse event was reported.

Conclusions

Pembrolizumab combined with Temozolomide is an effective and well-tolerated 1L regimen for Chinese patients with metastatic acral melanoma.

Clinical trial identification

ChiCTR2100050073.

Editorial acknowledgement

Legal entity responsible for the study

Y. Ding.

Funding

Has not received any funding.

Disclosure

All authors have declared no conflicts of interest.