EPIX Pharmaceuticals, Inc. has received a response from the US Food and Drug Administration (FDA) regarding the company's appeal for immediate approval of Vasovist (gadofosveset trisodium injection). In this response, the FDA, while denying the immediate approval of Vasovist, indicated that further clinical trials may not be necessary to gain approval.

The FDA had previously indicated that one or two additional pivotal clinical trials would be required for approval. Instead, the FDA now stated that a blinded re-read of the images obtained from the previously completed phase III clinical trials of Vasovist could support approval of Vasovist if the results are positive.

"We are delighted that the FDA has provided a potential path to approval for Vasovist without the requirement for additional clinical studies. Specifically, the FDA has now accepted that the image acquisition in the four previously conducted phase III studies was of sufficient quality to potentially provide substantial evidence of the efficacy of Vasovist," stated Andrew Uprichard, M D, president and head of research and development at EPIX. "In its letter, the FDA stated that it recommends the currently available images from the pivotal studies be re-analysed as the core of evidence needed to support the potential approval of Vasovist."

The response from the FDA is a result of a formal appeal EPIX filed on February 28, 2007 to the director of the Centre for Drug Evaluation and Research (CDER) at the FDA, asking the CDER director to approve the company's novel blood-pool imaging agent Vasovist. In its response, the FDA strongly recommended that EPIX work closely with the FDA to develop the appropriate protocol for the re-read in a Special Protocol Assessment (SPA)-like fashion, including how the reading will be done, how the data from the re-reading will be analysed and a plan for statistical analysis, prior to conducting a re-read of the images.

EPIX intends to quickly begin working with the FDA's division of Medical Imaging and Haematology Products to develop a jointly agreed-upon protocol for the blinded re-analysis of the phase III images. After the re-reads are completed and an amended submission is provided by EPIX, the FDA will have up to 180 days to review the submission.