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# FDA Reviewers Question Stanssoporfin Safety
- URL: https://www.fdaweb.com/fda-reviewers-question-stanssoporfin-safety/
- Published: 2018-05-02T12:00:00.000Z
- Updated: 2026-09-15T00:02:24.000Z
- Author: David McFarland
- Tags: Drugs, #legacy-id-D5141348

FDA says that one dose of InfaCare Pharmaceutical’s stannsoporfin to treat neonates who are at high risk for developing serious complications related to severe hyperbilirubinemia significantly reduced bilirubin levels, but could lead to long-term neurological risk. The assessment is in a briefing document prepared in advance of a 5/3 joint meeting of the agency’s Gastrointestinal Drugs Advisory Committee and its Pediatric Advisory Committee to consider the stannsoporfin application.

Stannsoporfin is a tin-based heme oxygenase inhibitor for which the company, a Mallinkrodt unit, is seeking an indication for treating neonates greater than or equal to 35 weeks of gestational age with indicators of hemolysis who are at risk of developing severe hyperbilirubinemia.

The reviewers report that InfaCare conducted three trials with the drug given as a singular intramuscular injection. They said results of the largest trial favored stannsoporfin. However, they said, the two other trials differed from the largest trial and from each other in methodology and their results were not internally consistent. None of the trials directly examined the drug’s effect on complications from hyperbilirubinemia.

According to the document, the reviewers have little safety information to go on at this point because only 34 patients have completed a one-year neurological development assessment and only seven have had a two-year neurological assessment, which is not enough to characterize the potential risk of long-term neurodevelopment issues related to stannsoporfin. However, they said, there have been signs that the drug might be associated with speech and/or hearing deficits. The reviewers also noted their assessment is complicated by the fact that hyperbilirubinemia itself can be associated with neurodevelopmental deficits.

Committee members are being asked to comment on the sufficiency of the clinical trials, whether safety and efficacy have been adequately established, whether the risk/benefit favors approval, recommended dosing, and how a Risk Management and Mitigation Strategy and a postmarketing trial to better assess benefits and risks long-term might be structured.