FDA CDMO warning letters nearly tripled from 39 (2023) to 111 (2025), exposing systemic quality failures at the contract manufacturers that biotech startups depend on

Small and mid-size biotech companies that outsource drug manufacturing to CDMOs face escalating quality and supply risks as FDA warning letters to manufacturing facilities have surged -- from 39 in 2023 to 78 in 2024 to 111 in 2025. Biotech sponsors have limited visibility into CDMO operations and limited leverage to enforce quality standards, yet a single FDA warning letter can halt production and jeopardize a company's entire clinical program or commercial supply. Why it matters: 26% of biopharma respondents cite regulatory violations as the top reason CDMOs lose bids, so the CDMO selection process is fraught with hidden risk that due diligence often fails to uncover, so when a CDMO receives a warning letter mid-production the sponsor faces months-long delays to transfer manufacturing to another facility, so clinical trial timelines slip or commercial supply is interrupted (as happened when Novo Nordisk's Catalent Indiana fill-finish facility received an 'official action indicated' classification from FDA), so patient access to approved therapies is directly threatened by manufacturing quality failures at facilities the drug developer does not own or control. The structural root cause is that the CDMO industry consolidated rapidly through private equity roll-ups (Catalent, Lonza, Samsung Biologics) that prioritized capacity expansion and margin improvement over quality system investment, while the FDA's inspection cadence could not keep pace with the explosion of new facilities and product transfers.