Disc Medicine, Inc has encountered a setback in its journey to secure approval for bitopertin, a treatment for erythropoietic protoporphyria (EPP), following a Complete Response Letter (CRL) issued by the US Food and Drug Administration (FDA) on February 13, 2026.
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stocktitan.netbiospace.comThe CRL highlighted concerns regarding the clinical benefit of the drug, specifically questioning the use of a surrogate endpoint—the percent change in whole blood metal-free protoporphyrin IX (PPIX)—as a predictor of efficacy.
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biospace.comstocktwits.comThe FDA's decision to issue a CRL came as a surprise to many analysts, given that bitopertin had met what some viewed as key criteria for accelerated approval.
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biospace.comHowever, the FDA noted that the data provided by Disc did not sufficiently link the change in PPIX levels to meaningful clinical outcomes, leaving significant uncertainty regarding the drug's effectiveness.
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stocktwits.comIn light of this feedback, Disc Medicine is focused on its ongoing Phase 3 APOLLO trial, which aims to enroll around 150 patients suffering from EPP and X-linked protoporphyria.
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barchart.comThis trial is designed not only to assess the percent change in PPIX but also to evaluate the average monthly time patients can spend in sunlight without experiencing pain from phototoxic reactions, a critical measure given the nature of the condition.
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biospace.combarchart.comDisc anticipates completing enrollment for the APOLLO trial by March 2026, ahead of its initial timeline, with topline data expected by the end of that year.
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barchart.comThe company plans to utilize data from this trial to respond to the FDA's CRL and hopes to request a Type A meeting with the agency to clarify its resubmission strategy.
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barchart.comstocktwits.comThe FDA's requirement for additional evidence demonstrates the agency's commitment to ensuring that any potential treatment for EPP is backed by robust clinical data.
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biospace.comDisc’s CEO John Quisel expressed confidence that the concerns raised by the FDA are "readily addressable" and affirmed the company's commitment to delivering a potentially disease-modifying therapy to the EPP community.
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barchart.comWhile the CRL represents a delay in the approval process, analysts believe that if all goes well, a new decision from the FDA could be anticipated by mid-2027, contingent on the results of the APOLLO trial.
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stocktwits.comDisc Medicine remains hopeful that the APOLLO trial will provide the necessary data to support the efficacy of bitopertin, paving the way for future discussions with the FDA regarding its approval potential.
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barchart.comAs the company navigates this next phase, it is also worth noting that Disc Medicine is well-positioned financially, with approximately $791 million in cash and equivalents reported as of December 31, 2025, which should sustain its operations into 2029.
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barchart.comThis financial stability allows Disc to focus on its clinical programs and regulatory strategies without immediate pressure to secure additional funding.In conclusion, Disc Medicine is diligently working to address the FDA's concerns regarding bitopertin and is committed to advancing the APOLLO trial, which it hopes will provide the necessary evidence for a successful resubmission.The coming months will be critical for the company as it aims to fulfill its promise to the EPP patient community and secure a pathway to approval for its innovative treatment.
