Dear Editors Human pancreatic islets are regulated as a drug in the United States, requiring a biologic license application (BLA) approval for allotransplantation outside of clinical trials.1 The goal of the BLA is to prove that drug manufacturing consistently provides a well-defined, high-quality product, with verified characteristics that assure the desired clinical effect. Such verification is considered essential for clinical safety and efficacy of any drug. No US academic institutions have been capable of submitting a BLA for pancreatic islets over the last 20 y, which led to a gradual demise of the field.1 Recently, a private company has filed a BLA for human islets and the Food and Drug Administration (FDA) Advisory Committee members reviewed the application on April 15, 2021.2 Herein, we share findings from that meeting as they have major implications for the field of islet transplantation. FDA advisors confirmed that islet transplantation has a favorable benefit-risk profile for certain patients with type 1 diabetes. This conclusion is not surprising to the transplant community, as favorable clinical outcomes have been well documented over the last 20 y.1 However, the main question: whether the BLA should be approved, was not asked and remains unanswered. Moreover, during the meeting, the FDA presented its own analysis of the BLA data. FDA concluded that “the quality and potency of the human islets may not be reliably defined, and critical quality attributes of the islets (islet characteristics based on the release criteria) did not correlate with islet function.”2 Basically, this means that the main goal of the BLA has not been achieved. Thus, BLA approval has no merit. However, the final FDA decision is yet to be made. Based on the scientific evidence, we call on the FDA to reach the most rational decision: reject the BLA and allow human pancreatic islets to be included into the definition of human organs under the OPTN Final Rule. This will result in proper islet regulation, as with any other organ for transplantation. This was proposed in recent publications and directly to the FDA and Health and Human Services.3,4 Unfortunately, an FDA representative recently renounced our proposition.5 Alternatively, an FDA decision to reject the BLA but continue holding the same drug-related requirements would inevitably prevent any clinical use of human islets indefinitely in the United States. On the other hand, the FDA approval of a clearly deficient BLA would be detrimental. The BLA-holding commercial entity would be authorized to sell human islets of unverifiable quality and potency. Transplant centers will have no choice but to purchase and transplant them in patients. Such regulation would compromise patient safety and FDA credibility. Moreover, it would be impossible to verify the islet manufacturer performance, even when islet graft fails, since the ultimate reason for failure cannot be established. These new FDA findings provide further strong evidence that islets do not fit into drug regulatory framework and should be instead included into the organ for transplant regulations by the Health and Human Services Secretary.
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