Tiny pharma hits a new low with FDA refusing to review company's response to its CRL
Just before the long weekend, tiny Zosano Pharma revealed another blow to its application for approval for a migraine patch.
The FDA said the company’s resubmission for the patch didn’t adequately respond to the deficiencies identified in the FDA’s rejection letter, and that the agency will not review this re-submitted application until a new complete response is submitted.
Fremont, CA-based Zosano sent its response to the FDA last month, trying to resurrect the generic triptan zolmitriptan in a new delivery system known as Qtrypta. The agency in October 2020 rejected the patch over inconsistent exposure levels across multiple clinical trials, as well as other issues.
The FDA found that Zosano hadn’t adequately shown its product gave patients similar exposure to the migraine drug as an existing nasal spary, as the company explained Friday in its filing:
Among other things, the FDA’s response letter stated that the Company’s strategy for establishing a pharmacokinetic (‘PK’) bridge to Zomig Nasal Spray 5 mg (‘Zomig NS’) by relying primarily on data from the Company’s recently completed Phase 1 PK study (‘Study CP-2021-001’) was not acceptable, due in part to differences between the design of Study CP-2021-001, which compared the PK of M207 to two sequential doses of 5 mg Zomig NS, and the criteria for re-dosing set forth in the labeling instructions for 5 mg Zomig NS.
Zosano noted that FDA’s response letter described alternative methods to establish equivalence to 5 mg Zomig NS, including: “(i) by demonstrating bioequivalence to Zomig NS using standard criteria for all PK exposure metrics, including through a combination of relevant PK data and modeling or simulation procedures; or (ii) by conducting a relative bioavailability study in healthy volunteer subjects.”
But the company, whose stock price fell by about 37% early Tuesday, said it may have to reevaluate whether it can continue to pursue the patch.
“The Company is evaluating next steps in relation to the FDA’s response letter as part of its financial and strategic planning; however, there can be no assurances that the Company’s resources will enable the Company to continue to pursue FDA approval of M207,” the SEC filing said.
Zosano’s application for Qtrypta was based on a Phase II/III trial from 2017 that met both co-primary endpoints, with 41.5% of patients treated with the 3.8 mg dose of Qtrypta achieving pain freedom at 2 hours, and 68.3% reporting freedom from their most bothersome symptom also at 2 hours.
In a long-term safety study, Zosano said 95% of side effects were mild, and more than 80% resolved within 48 hours. Less than 2% of patients reported triptan-like neurological side effects typically found in the class, such as dizziness and paresthesia. But in the CRL, FDA cited high plasma concentration levels of zolmitriptan in five patients.
Zosano has had a rocky history after raising $50 million for an IPO at the beginning of 2015. Soon after debuting, the company’s $11 share price was shredded when its two big partners — Eli Lilly and Novo Nordisk — pulled out of their collaborations.
“As previously disclosed, the Company has retained SierraConstellation Partners, LLC as an independent financial advisor to assist in exploring financial and strategic alternatives to maximize value, which may include, but not be limited to, asset or equity sales, joint venture and partnership opportunities, and restructuring, amendment or refinancing of existing liabilities, and is evaluating various alternatives to improve its liquidity,” Zosano added.