Preliminary Data on Genta’s Melanoma Drug Sends Firm Crashing
Genasense failed to significantly improve progression-free survival, and overall survival cannot yet be evaluated.
Interim analysis of Phase III data on Genta’s melanoma treatment, Genasense®, revealed that it did not meet one of its primary endpoints or any of the secondary endpoints that are evaluable at this time. The company has thus decided to postpone submission of an NDA this year.
Genta, already trading below $1, lost just over 81% of its value in early morning trading. After closing yesterday at $0.65, it opened today at $0.12.
The Phase III study did not show a statistically significant benefit for its co-primary endpoint of progression-free survival. Secondary endpoints of overall response rate and disease control rate also did not show a statistically significant benefit; disease control rate includes complete and partial responses as well as stable disease at last for three or more months.
It is too early to evaluate the statistical significance of durable response, a secondary endpoint that measures the proportion of patients who achieved a complete or partial response that lasts more than or equal to six months. It is also too early to evaluate overall survival, another primary endpoint.
The Phase III trial is designed as a randomized, double-blind, placebo-controlled study of dacarbazine administered with or without Genasense in patients who have not previously received chemotherapy.
Genta is also studying Genasense in chronic lymphocytic leukemia (CLL; Phase III) and non-Hodgkin’s lymphoma (Phase II). The drug candidate inhibits production of Bcl-2, a protein made by cancer cells that is thought to block chemotherapy-induced apoptosis. By reducing the amount of Bcl-2 in cancer cells, Genasense may enhance the effectiveness of current anticancer treatment.
Genta has also had a tough time gaining approval for Genasense in relapsed or refractory CLL, which was initially reviewed and deemed nonapprovable by the FDA in December 2006. After submitting new information, on March 6, the agency’s Center for Drug Evaluation and Research said that the amended NDA was still insufficient to support marketing authorization. FDA has asked Genta to conduct a confirmatory clinical trial with Genasense in relapsed or refractory CLL.