Nabriva hit with another FDA setback with complete response letter for antibiotic Contepo

Nabriva tied the FDA's letter to travel restrictions from the coronavirus. (FDA)

Nabriva Therapeutics threaded the needle from biotech to pharma after it notched its first FDA approval for antibiotic Xenleta back in August. But manufacturing issues for a second antibiotic in Nabriva's pipeline have drawn the FDA's ire, and now the pandemic has stopped the drugmaker's second shot at an approval.

The FDA hit Nabriva with a second complete response letter (CRL) for antibiotic Contepo (fosfomycin), citing issues at one of the drugmaker's European contract manufacturing sites, Nabriva said Friday.

Nabriva blamed the letter on the FDA's inability to perform on-site inspections at the plant due to pandemic-related travel restrictions. Without FDA inspectors on site, Nabriva was unable to fix issues outlined in the first CRL it received back in April 2019, the company said.

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"In general, previously identified product quality and facility inspection related observations at our contract manufacturing partners are required to be satisfactorily resolved before the (new drug application) may be approved," Nabriva said in a release.

Nabriva will aim for a Type A meeting with regulators to discuss "appropriate next steps and the FDA’s plans for completing foreign facility inspections." The drugmaker said the FDA's letter did not request additional clinical data or question the drug's safety or efficacy.

In August, Nabriva said it planned to refile its Contepo application for expedited review after addressing the FDA's issues with its European contract manufacturing site.

The FDA originally knocked the contract manufacturer for inspection and manufacturing deficiencies, but Nabriva reported it had not received a warning letter for anything found at the site during routine FDA inspections.

Contepo, a potential treatment for complicated urinary tract infections, including acute pyelonephritis, would become Nabriva's second approved drug after antibiotic Xenleta notched an FDA approval last year.

RELATED: Nabriva scores its first FDA nod with novel antibiotic Xenleta

The FDA in August approved Xenleta (lefamulin) to treat community-acquired bacterial-pneumonia (CABP) as the first in a new class of antibiotics called pleuromutilins, which target a different protein synthesis binding site than older competitors. Nabriva planned to market Xenleta, approved in both oral and intravenous formulations, as a new answer for CABP, which affects around 5 million Americans each year.