Vemurafenib plus rituximab associated with durable complete response in HCL

Vemurafenib plus rituximab produced a durable complete response in the majority of patients with refractory or relapsed hairy-cell leukemia (HCL), according to results from a small phase 2 study published in the New England Journal of Medicine.

In this single-center, academic trial, 30 patients with HCL with a mean of 3 prior therapies, were administered vemurafenib for 8 weeks plus concurrent and sequential rituximab over a period of 18 weeks.

In the intention-to-treat population, 87% (n = 26) had a complete response, including 10 patients that had been refractory to chemotherapy, 5 refractory to rituximab, and 7 previously been treated with BRAF inhibitors.

After a median of 2 and 4 weeks, thrombocytopenia and neutropenia were resolved, respectively.

Of the patients who achieved a complete response, 65% were cleared of minimal residual disease (MRD) and relapse-free survival with a response was 85% at a median follow-up of 34 months.

At a median follow-up of 37 months, progression-free survival for all patients was 78%.

Post hoc analyses found that MRD negativity and no prior BRAF inhibitor treatment were correlated with longer relapse-free survival.

Reference
Tiacci E, De Carolis L, Simonetti E, et al. Vemurafenib plus rituximab in refractory or relapsed hairy-cell leukemia. N Engl J Med. 2021; 384:1810-1823. DOI: 10.1056/NEJMoa2031298