=Verastem (VSTM) : positive results in leukemia drug study

Verastem reports clinical data from the Phase 3 DUO Study; improves Progression Free Survival in Relapsed or Refractory Chronic Lymphocytic Leukemia  

• Co announced the presentation of the results from the Phase 3 DUO study evaluating the efficacy and safety of duvelisib in patients with relapsed or refractory chronic lymphocytic leukemia (CLL)/small lymphocytic lymphoma
• The DUO study met its primary endpoint with oral duvelisib monotherapy achieving a statistically significant improvement in median PFS (mPFS) compared to ofatumumab in patients with relapsed or refractory CLL/ SLL per a blinded Independent Review Committee (IRC) using iwCLL or revised IWG Response Criteria, representing a 48% reduction in the risk of progression or death. Similar efficacy of duvelisib was observed regardless of whether patients had 17p deletion .
  • The primary outcome of mPFS via IRC review in the del[17p] subpopulation significantly favored duvelisib over ofatumumab (12.7 months vs 9.0 months, respectively; HR=0.41; p=0.0011), representing a 59% reduction in the risk of progression or death. Per investigator assessment, duvelisib demonstrated a mPFS of 17.6 months, compared to 9.7 months for ofatumumab.
  • Duvelisib maintained a PFS advantage in all patient subgroups analyzed as a subset of pre-specified sensitivity analyses.
• The secondary efficacy outcome of ORR via IRC assessment according to modified iwCLL/IWG, significantly favored duvelisib over ofatumumab, and reduced lymph node burden  in most patients vs ofatumumab (85% vs 16%).
  • In the del[17p] subpopulation of patients, ORR was also significantly higher for duvelisib compared to ofatumumab, 70.0% versus 43.0%, respectively (p=0.0182). The Overall Survival (OS) in the ITT population was similar for those randomized to duvelisib and to ofatumumab during the study (HR=0.99; p=0.4807), demonstrating no detrimental effect on OS and was likely due to other available therapies following progression.
  • Patients who progressed in the DUO study were given option to enroll in a crossover study to receive the opposite treatment. In the optional crossover study, 89 patients who were previously treated with ofatumumab in DUO and experienced disease progression were subsequently treated with duvelisib monotherapy. As in the parent DUO study, duvelisib demonstrated robust clinical activity in this crossover study with an ORR of 73%, a median duration of response of 12.7 months and a mPFS of 15 months by investigator assessments.