Specialty biopharmaceutical company Santarus, Inc. (NASDAQ:SNTS) and biotech company Pharming Group NV (NYSE Euronext:PHARM) today announced the receipt of a "refusal to file" letter from the U.S. Food and Drug Administration (FDA) for the RHUCIN® (recombinant human C1 inhibitor) Biologics License Application (BLA) submitted by Pharming. In the letter the FDA indicated that the BLA was not sufficiently complete to enable a critical medical review.
In reaching its conclusion, the FDA indicated that the previously conducted studies evaluating RHUCIN for the treatment of acute attacks of Hereditary Angioedema (HAE) did not provide data for a sufficient number of subjects to support the proposed dose of 50 U/kg and lacked prospective validation of the visual analog scale used in measuring the clinical effects of RHUCIN. The FDA also provided other comments on the prior clinical studies and indicated that they will provide additional feedback on the design of the ongoing Phase IIIb clinical study, which had been initiated based on previous discussions with the FDA. In addition, the FDA requested that the results of the Phase IIIb clinical study be included in any future BLA submission for RHUCIN.
The FDA has the ability to formally file or refuse to file an application within 60 days of the completion of the submission, which occurred in late December 2010. Both companies intend to meet with the FDA at the earliest opportunity to discuss the issues raised in the FDA letter and to reach a more comprehensive understanding of what would be required for the BLA to be accepted for review.
Santarus has licensed certain exclusive rights from Pharming to commercialize RHUCIN in North America for the treatment of acute attacks of HAE and other future indications. Under the terms of the license agreement, Pharming is responsible for conducting and paying for the current Phase IIIb clinical study with RHUCIN in the treatment of acute attacks of angioedema in patients with HAE.