FDA's Maxamine review
The FDA on Tuesday released its review of Maxim Pharmaceuticals Inc.'s Maxamine histamine immune stimulant, raising questions about the efficacy data in the NDA for the use of Maxamine in combination with interleukin-2 to treat advanced metastatic melanoma that has metastasized to the liver. Maxim (MAXM; SSE:MAXM) is scheduled present its case to the Oncologic Drugs Advisory Committee (ODAC) on Wednesday.
The FDA reviewers wrote that on an intent-to-treat analysis, median survival in the 74 patients with liver metastases given IL-2 alone was 154 days versus 283 days in the 55 patients given IL-2 plus Maxamine (p=0.004). However, the reviewers noted that "analysis of the distribution of known prognostic factors in metastatic melanoma found many imbalances between the two treatment arms in patients with liver metastases. These included performance status, albumin, disease-free interval, and number of metastatic sites. These imbalances consistently favored the histamine/IL-2 arm." Applying an adjusted analysis using prognostic factors on the subgroup of patients with liver metastases, "the large treatment effect favoring the histamine/IL-2 combination diminished and the probability of a false positive finding increased," according to the review. The p-value based on this analysis was 0.0806. ...