FDA Places Partial Clinical Hold On Vertex' Ongoing Phase 2 U.S. Study Of VX-135

(RTTNews) - Vertex Pharmaceuticals Inc. (VRTX) announced that the U.S. Food and Drug Administration has placed a partial clinical hold on its ongoing Phase 2 U.S. study of the nucleotide analogue hepatitis C virus polymerase inhibitor VX-135.

This partial clinical hold prevents evaluation of a 200 mg dose of VX-135 in the U.S. study following observation of reversible elevated liver enzymes in patients receiving 400 mg of VX-135 in combination with ribavirin in a Phase 2 study in Europe.

Meanwhile, the company said evaluation of a 100 mg dose of VX-135 in combination with ribavirin as part of the 12-week Phase 2 study in the U.S. is continuing as planned.

The company's stock, which closed Thursday's session at $87.62, declined over 8 percent to $80.00.

The company said it is committed to continuing to work closely with the FDA to provide the data needed to support evaluation of a 200 mg dose of VX-135 in the U.S.