Who Owns Desmoteplase?

Desmoteplase is one of the most distinctive drug candidates in thrombolytic research. The active ingredient is a recombinant form of Desmodus salivary plasminogen activator alpha-1, a protein found naturally in the saliva of the common vampire bat (Desmodus rotundus). Vampire bats feed exclusively on blood and have evolved potent anticoagulant and thrombolytic proteins in their saliva to keep blood flowing from their prey's wounds. Desmoteplase was identified as a promising therapeutic candidate because of its high fibrin specificity and lack of neurotoxicity compared to alteplase.

PAION AG, a biopharmaceutical company based in Aachen, Germany, identified desmoteplase and initiated its clinical development. The first Phase II trial, known as DIAS (Desmoteplase In Acute Ischemic Stroke), began in March 2001 and completed in October 2003. The trial was an MRI-based study evaluating desmoteplase administered 3 to 9 hours after stroke symptom onset, an extended window beyond the 3-hour limit for alteplase at the time. The results, published in Stroke in January 2005, showed promising efficacy and safety signals, with higher reperfusion rates and better clinical outcomes at higher doses compared to placebo.

A second Phase I/II trial, DEDAS (Dose Escalation of Desmoteplase in Acute Ischemic Stroke), started in March 2003 and completed in October 2004. This trial explored dose optimization and confirmed the safety profile. The combined Phase II results supported advancement to Phase III, and PAION raised funding to initiate key Phase III trials.

PAION entered into a licensing agreement with Lundbeck for desmoteplase development and commercialization. PAION also closed an agreement with Forest Laboratories for North American rights in 2004. The partnership with Lundbeck was expanded in 2009, giving Lundbeck global exclusive rights and full control of the development program.

The first Phase III trial, DIAS-2, was conducted and top-line results were announced on May 31, 2007. DIAS-2 showed a surprisingly high responder rate in the placebo group, with no difference compared to desmoteplase on the primary clinical efficacy endpoint. Post-hoc analysis revealed that nearly half of DIAS-2 patients lacked visible vessel occlusion before treatment, as the trial had not screened for vessel occlusion using angiography. When analyzing only patients with confirmed vessel occlusion, a positive effect of desmoteplase versus placebo was observed. This finding informed the design of subsequent trials.

DIAS-3, a Phase III double-blind, randomized, placebo-controlled trial, enrolled 492 patients from 77 hospitals in 17 countries between February 2009 and November 2013. The trial specifically enrolled patients with occlusion or high-grade stenosis in major cerebral arteries, confirmed by angiography. Patients received desmoteplase (90 micrograms per kilogram) or placebo 3 to 9 hours after symptom onset. The primary outcome was a favorable modified Rankin Scale score (0 to 2) at day 90. Results, published in The Lancet Neurology in 2015, showed that 51% of desmoteplase patients and 50% of placebo patients achieved a favorable outcome, a non-significant difference. The trial failed to meet its primary endpoint.

DIAS-4, a second Phase III trial, was started in April 2009 but was terminated early. The termination was based on the DIAS-3 results, which indicated that the DIAS-4 study was unlikely to reach its primary endpoint with the current protocol. DIAS-4 enrolled 270 patients before being stopped.

Following the failure of DIAS-3 and the termination of DIAS-4, the desmoteplase development program has not advanced. No further Phase III trials have been initiated, and desmoteplase has not been submitted to any regulatory authority for approval. Lundbeck retains ownership of the desmoteplase rights but has not publicly disclosed plans to resume development. The drug remains an investigational compound with no approved indications.