Achaogen hits, then misses: FDA OKs Zemdri for cUTIs, but rejects second indication
Following an advisory committee’s suggestions back in May, the FDA has handed one approval — and one rejection — to Achaogen’s lead antibiotic.
Achaogen’s drug, which now goes by the brand name Zemdri (plazomicin), has been OK’ed to treat complicated urinary tract infections. However, the agency issued a complete response letter (CRL) in response to Achaogen’s bid to treat bloodstream infections, citing lack of effectiveness of the drug in a clinical study. The company said it plans to meet with the FDA to see if there’s a “feasible resolution” to address the CRL.
A large part of what seems to have doomed Achaogen’s plans for the bloodstream infections indication was a smaller-than-expected sample size that complicated statistical analysis. The biotech had to amend protocols for its Phase III study (ACHN-490-007) because it could only enroll 37 patients out of the planned 286. That resulted in statistical limitations proving Zemdri’s superior efficacy to colistin in the comparator arm — a point of discussion among the FDA’s advisory committee on the drug earlier this year.
For cUTI, on the other hand, committee members had no problem unanimously endorsing Zemdri based on a study that showed it was noninferior to meropenem, even considering a larger margin of 15% (versus a conventional 10%) the FDA sanctioned.
“The approval of Zemdri marks a significant milestone for Achaogen and we are excited to offer healthcare practitioners a new treatment option for patients with certain serious bacterial infections,” said Achaogen’s CEO Blake Wise in a statement. “Zemdri is designed to retain its potent activity in the face of certain difficult-to-treat multidrug resistant infections, including CRE and ESBL- producing Enterobacteriaceae.”
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