A Pilot Trial of the Combination of Vemurafenib with Adoptive Cell Therapy in Patients with Metastatic Melanoma.

PURPOSE

This pilot feasibility clinical trial evaluated the coadministration of vemurafenib, a small-molecule antagonist of BRAF mutations, and tumor-infiltrating lymphocytes (TIL) for the treatment of metastatic melanoma.

EXPERIMENTAL DESIGN

A metastatic tumor was resected for growth of TILs, and patients were treated with vemurafenib for 2 weeks, followed by resection of a second lesion. Patients then received a nonmyeloablative preconditioning regimen, infusion of autologous TILs, and high-dose interleukin-2 administration. Vemurafenib was restarted at the time of TIL infusion and was continued for 2 years or until disease progression. Clinical responses were evaluated by Response Evaluation Criteria in Solid Tumors (RECIST) 1.0. Metastases resected prior to and after 2 weeks of vemurafenib were compared using TCRB deep sequencing, immunohistochemistry, proliferation, and recognition of autologous tumor.

RESULTS

The treatment was well tolerated and had a safety profile similar to that of TIL or vemurafenib alone. Seven of 11 patients (64%) experienced an objective clinical response, and 2 patients (18%) had a complete response for 3 years (one response is ongoing at 46 months). Proliferation and viability of infusion bag TILs and peripheral blood T cells were inhibited in vitro by research-grade vemurafenib (PLX4032) when approaching the maximum serum concentration of vemurafenib. TCRB repertoire (clonotypes numbers, clonality, and frequency) did not significantly change between pre- and post-vemurafenib lesions. Recognition of autologous tumor by T cells was similar between TILs grown from pre- and post-vemurafenib metastases.

CONCLUSIONS

Coadministration of vemurafenib and TILs was safe and feasible and generated objective clinical responses in this small pilot clinical trial. Clin Cancer Res; 23(2); 351-62. ©2016 AACRSee related commentary by Cogdill et al., p. 327.