Gilead Sciences, Inc. (GILD - Free Report) recently presented encouraging data on its pipeline candidate idelalisib (formerly GS-1101) from a phase II study (study 101-08: n=64). The study is evaluating idelalisib combined with Roche Holding AG’s (RHHBY - Free Report) Rituxan/MabThera (rituximab) in treatment-naïve patients (aged ≥65 years) suffering from chronic lymphocytic leukemia (CLL). CLL, the second most common leukemia form in the US, refers to a slow-growing cancer. It stimulates the production of multiple mature white blood cells.
The results stated that the regimen achieved an overall response rate of 97% with estimated progression-free survival of 93% at 24 months. Encouraged by the results of the phase II study, Gilead intends to evaluate idelalisib for the indication in phase III studies.
Gilead plans to present detailed results from the phase II study at the annual meeting of the American Society of Clinical Oncology. The primary endpoint of the open-label, single-arm phase II study is the overall response rate. It refers to the proportion of patients achieving a complete or partial response with this regimen. As per the provisions of the trial, patients who complete 48 weeks of the combination therapy without the disease worsening could continue to receive idelalisib in an extension study.
Successful development and commercialization of idelalisib for the indication would boost Gilead’s top line since the CLL market offers significant commercial potential. Apart from CLL, Idelalisib is also being evaluated in other oncology indications such as indolent non-hodgkin’s lymphoma and mantle cell lymphoma.
Gilead carries a Zacks Rank #3 (Hold). The companies that look better-positioned include Osiris Therapeutics and Cubist Pharmaceuticals Inc. . Both are Zacks Rank #2 (Buy) stocks.