Genta To File Complaint With FDA Over Statistical Analysis Of Genasense Data
This article was originally published in The Pink Sheet Daily
Executive Summary
Complaint relates to 2004 analysis of Genasense progression-free survival data in melanoma, presented to the Oncologic Drugs Advisory Committee.
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Genta plans to file a formal complaint and request a correction of information with FDA, challenging a key statistical analysis made by the agency in its 2004 review of the Bcl-2 inhibitor Genasense (oblimersen) for the treatment of melanoma. The statistical analysis, used during the Oncologic Drugs Advisory Committee meeting in May 2004 to discredit a finding that treatment with Genasense in combination with dacarbazine resulted in a statistically significant increase in progression-free survival, is erroneous, Genta claims. "We were unable to verify the integrity of this highly non-standard analysis in advance of the ODAC meeting," the company said. "Since then, we have been able to test the statistical model, and we show clearly that the analysis was erroneous." Genta is seeking a formal public acknowledgement of the error, removal of the analysis from the FDA Web site and a revision of the meeting transcript, the firm reported. Genta is filing the complaint under the Federal Data Quality Act. During ODAC's review in 2004, the advisory group concluded that Genasense had an effect on response rates in metastatic melanoma but not on progression-free survival or overall survival (1 (Also see "Genasense Melanoma Progression-Free Survival Data Do Not Show "Real Effect," Cmte. Says" - Pink Sheet, 3 May, 2004.)). Genta withdrew the NDA following the ODAC meeting and its partner Aventis (now Sanofi-Aventis) returned all rights to the company, which has since been focusing on development of Genasense in multiple myeloma and chronic lymphocytic leukemia (2 (Also see "Genta Targeting Year-End Genasense NDA In Myeloma Or Lymphocytic Leukemia" - Pink Sheet, 3 Aug, 2004.)). On April 18, the Berkeley Heights, N.J. company announced it is initiating a new Phase III study in advanced melanoma patients, using biomarker testing to identify a pool of treatment naive patients likely to respond best to treatment with Genasense plus dacarbazine, patients with normal serum lactate dehydrogenase levels (3 (Also see "Genta Returns To Old Territory With New Genasense Study" - Pink Sheet, 18 Apr, 2007.)). The European Medicines Agency's Committee for Medicinal Products for Human Use adopted a negative opinion of Genta's marketing authorization application for Genasense plus dacarbazine for treatment of patients with advanced melanoma April 26, citing similar survival rates in patients receiving Genasense compared to dacarbazine alone. Genta said it had been anticipating a negative response. However, the company plans to request a re-examination within 60 days, which will delay any formal action by four to six moths. "We believe the safety and efficacy results for Genasense plus dacarbazine are superior to any other product ever considered by regulatory authorities for advanced melanoma," the agency said. The company is making Genasense available to patients through a compassionate use program. The firm also recently appealed FDA's "not approvable" letter for Genasense in CLL based on complete response data (4 (Also see "Genta Appeals FDA’s Genasense “Not Approvable” Decision" - Pink Sheet, 4 Apr, 2007.)). -Jessica Merrill ([email protected]) |