The latest failures are in two Phase III trials of alfimeprase, a drug developed by Nuvelo in collaboration with Bayer. The news comes on top of the announcement earlier in the week that Nexavar (sorafenib) has failed a Phase III clinical trial looking at its effectiveness as a melanoma treatment.
Nexavar was also developed in collaboration, this time with Onyx Pharmaceuticals who, like Nuvelo are also based in California, US.
Since the announcement, shares in Nuvelo have plummeted from $20 (€15) to around $4.
The blocking of arteries and subsequent reduction in blood flow leads to a lack of oxygen in the affected area. If this area is in the periphery of the body, the result could be the loss of a limb. This is called peripheral arterial occlusion (PAO) and it is especially common in the legs.
The first trial of alfimeprase was designed to investigate how well the drug unblocked arteries with the aim of avoiding surgery within 30 days of beginning treatment.
The second trial did not meet its primary endpoint of unblocking a catheter within fifteen minutes.
Alfimeprase is designed to dissolve blood clots by directly degrading fibrin when delivered through a catheter at the point of a clot. Drugs already on the market, such as Genentech's Activase (alteplase) activate the plasminogen system to degrade clots. Large clots, such as those found with PAO would require large infusions. This is exacerbated by the fact that plasminogen levels can vary from clot to clot. This is especially true for the large clots characteristic of PAO.
Bayer has been less affected by the failures because they have a much larger pipeline than Nuvelo and Onyx, who only have two products each in their clinical pipelines.
Nuvelo have not given up on alfimeprase yet though."These outcomes are disappointing particularly for patients with acute PAO, who have few treatment options," said Dr Ted Love, chairman and chief executive officer of Nuvelo.
"We and our partner Bayer will conduct further analyses…to determine how to proceed with the development of alfimeprase, including the possibility of alternative dosing and delivery."
However, the company has temporarily suspended enrollment in other, ongoing Phase III trials of alfimeprase until this analysis is complete.
Last week, Onyx shares dropped over 30% to around $12.