The phase III study enrolled 120 patients who were given a combination of Genasense plus chemotherapy; another 121 patients were given chemotherapy alone. All patients in the study were diagnosed with advanced CLL, which means they had received, and failed, prior therapies.
Nineteen patients, or 16%, in the Genasense arm of the study achieved a major response -- defined as a complete response or so-called nodular partial response, compared to with eight patients, or 7%, in the control arm. This result, the study's primary endpoint, was statistically significant, albeit not robustly so with a so-called p value of 0.039. [A p value of 0.05 is required for a study to reach statistical significance, but strong data typically have a p value of less than 0.01.]
But a more conventional primary endpoint in CLL studies looks at overall response rate, defined as a complete response, nodular partial responses and partial response. When the Genasense data were analyzed this way, overall response in the Genasense arm was 41%, less than the 45% overall response rate in the control arm.
Also, patients in the Genasense arm of the study progressed (their disease worsened) at a median time of 6.1 months, faster than the 8.9 months for patients in the control arm. Overall survival data were not analyzed, pending further maturing of the data.
Despite a series of setbacks this year that have left Genta reeling, the company seems intent to push ahead with Genasense's development. No doubt, persistence sometimes pays off. But for Genta, the second time will not likely be the charm.