End-to-end donor screening and manufacturing controls: complementary quality-based strategies to minimize patient risk for donor-derived microbiome therapeutics.

Advances in microbiome therapeutics have been motivated by a deeper understanding of the role that the gastrointestinal microbiome plays in human health and disease. The FDA approval of two stool-derived live biotherapeutic products (LBPs), REBYOTA® 150 mL enema (fecal microbiota, live-jslm; formerly RBX2660) and VOWST® oral capsules (fecal microbiota spores, live-brpk; formerly SER-109), for the prevention of recurrent CDI in adults following antibiotic treatment for recurrent CDI provides promise and insights for the development of LBPs for other diseases associated with microbiome dysfunction. Donor-derived products carry risk of disease transmission that must be mitigated through a robust donor screening program and downstream manufacturing controls. Most published recommendations for donor screening practices are prescriptive and do not include a systematic, risk-based approach for donor stool-derived products. A general framework for an end-to-end donor screening program is needed using risk management strategies for donor-derived microbiome therapeutic using a matrixed approach, combining the elements of donor screening with manufacturing controls that are designed to minimize risk to patients. A donor screening paradigm that incorporates medical history, physical examination, laboratory testing, and donor sample inspection are only the first steps in reducing risk of transmission of infectious agents. Manufacturing controls are the cornerstone of risk mitigation when screening unwittingly fails. Failure Mode and Effects Analysis (FMEA) can be used as a tool to assess for residual risk that requires further donor or manufacturing controls. Together, a well-reasoned donor program and manufacturing controls are complementary strategies that must be revisited and reexamined frequently with constant vigilance to mitigate risk to patients. In the spirit of full disclosure and informed consent, physicians should discuss any limitations in the donor screening and manufacturing processes with their patients prior to treatment with microbiome-based therapeutics.