No-go for Zosano as FDA knockback triggers suspension of transdermal migraine patch program

Zosano Pharma’s headaches are intensifying. With the FDA again knocking back its transdermal migraine patch, the biotech has suspended its M207 program and made more layoffs to preserve its dwindling cash reserves. 

The patch uses microneedles to deliver zolmitriptan, a selective serotonin receptor agonist that is already approved for use in the treatment of migraine attacks. Zosano reformulated the molecule, which is typically given orally, for transdermal delivery to accelerate absorption. However, the FDA has looked unfavorably on filings, issuing a complete response letter and then refusing to review a resubmission.

Zosano recently revealed the toll of the latest setback, disclosing the decision to suspend the M207 program despite the FDA granting it another year to resubmit its new drug application. The biotech took the step to preserve its cash reserves, which were down to $11.4 million as of April 26, 2022.

The suspension of the program is the latest in a series of actions designed to eke out Zosano’s remaining money. In March, Zosano revealed plans to lay off 31% of its staff. The biotech disclosed further staff cuts alongside news of the suspension of the M207 program, revealing it is laying off around 40% of the staff it has left. Zosano’s R&D team was down to 21 employees after the earlier round of layoffs.

As part of the latest round of cost-saving measures, Zosano suspended GMP manufacturing operations at its Fremont, California site and stopped activities at its contract manufacturers linked to the qualification of commercial manufacturing equipment. Zosano is “evaluating its long-lived assets for the impairment related to these actions.”

Work to find a strategic alternative is continuing. Anyone who wants to try to resurrect M207 will need to address the FDA’s request for additional data, which included results of a new bioavailability study, and hire additional employees to support a pre-approval inspection.