Cytokinetics ($CYTK) has some thinking to do after its lead program missed the mark in a Phase IIb trial, failing to move the efficacy needle in ALS, commonly known as Lou Gehrig's disease. The news sent the biotech's shares spiraling more than 60% downward in pre-market trading Friday.
The drug, tirasemtiv, works by increasing muscle sensitivity to calcium, thereby improving function in patients with the neurodegenerative ALS. In a 711-patient trial, however, tirasemtiv missed its primary efficacy endpoint of significantly improving muscle function compared to placebo, charting mixed results on secondary goals of respiratory benefits and other measures of muscle function, the biotech said, keeping detailed results to itself.
That leaves Cytokinetics at a decision point for an already troubled program. Last year, the South San Francisco company made an uncommon dosing error in the trial, accidentally giving sugar pills to patients in the treatment arm and thus forcing investigators to expand enrollment. The mistake delayed tirasemtiv's results by three months and racked up a $5 million charge for Cytokinetics.
Now, with a mid-stage miss in the books, the drug's future remains unclear.
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| Cytokinetics CEO Robert Blum |
"Understanding these results will require significant further review," CEO Robert Blum said in a statement. "Once we have fully evaluated the data from BENEFIT-ALS, we expect to determine whether there is a potential development path forward for tirasemtiv for the potential treatment of ALS and what may be the appropriate next steps."
Tirasemtiv's stumble comes on the heels of a setback for Cytokinetics' other lead program, the Amgen-partnered heart failure treatment omecamtiv mecarbil. An intravenous formulation of the drug failed in Phase IIb, Amgen ($AMGN) disclosed in September, and now the Big Biotech is waiting on data from a mid-stage study on oral omecamtiv mecarbil before deciding whether to head into Phase III or scrap the program.
Cytokinetics shares fell to around $5 on Friday morning, their lowest value since January 2013.
- read the statement