A Phase II Study of the BRAF Inhibitor, Vemurafenib, Plus Obinutuzumab in Patients With Previously Untreated Classical Hairy Cell Leukemia

Eligible patients will receive vemurafenib at a dose of 960mg orally twice daily (b.i.d.) continuously in cycles of 4 weeks (28 days) for a total of 4 cycles. In case of certain defined toxicities, dose reductions of vemurafenib by 50% (480mg b.i.d.) or interruptions of up to 15 days are permitted. If additional dose reduction is required, vemurafenib may be reduced to 240mg oral b.i.d.

Obinutuzumab will be administered concomitantly with vemurafenib starting at cycle 2 of treatment in cycles of 4 weeks. Obinutuzumab infusions will be administered at 1000mg per day on days 1, 8 and 15 during the cycle 2 and 1000mg per day every 4 weeks during the cycle 3 and 4 of treatment.