FDA WARNING_LETTER - Kaleido Biosciences, Inc. - March 03, 2021

This FDA Warning Letter, dated September 7, 2021, addresses Kaleido Biosciences, Inc. (Kaleido) regarding objectionable conditions observed during an FDA inspection from February 24 to March 3, 2021. The inspection, part of FDA’s Bioresearch Monitoring Program, evaluated Kaleido’s role as sponsor for clinical investigations of investigational drug KB109.

The primary violation identified is Kaleido's failure to submit Investigational New Drug (IND) applications for clinical investigations of KB109, specifically Protocols K031-120 and K032-120, which involved 350 and 49 human subjects, respectively. FDA regulations (21 CFR 312.20(a), 312.20(b), and 312.40(a)) require an IND before initiating clinical investigations of a drug subject to 21 CFR 312.2(a), unless exempt.

Kaleido argued KB109 was a food, not a drug, and the studies evaluated its effect on the microbiome and safety/tolerability in COVID-19 patients, not as a treatment. They cited GRAS status and potential as a medical food. However, FDA concluded KB109 was intended as a drug based on study objectives and endpoints, which assessed efficacy in mitigating and treating COVID-19