Investing.com -- Eli Lilly and Company (NYSE: LLY) fell 3% Monday, while Novo Nordisk (NYSE: NVO) rose 2% after Evercore ISI analyst Umer Raffat flagged a liver case in the FDA adverse event database that has "potential to create confusion" for Eli Lilly.

Raffat noted that a case of hepatic failure appeared in the FDA Adverse Event Reporting System for Foundayo, Eli Lilly’s oral GLP-1 drug. The case involved a 56-year-old male and may have occurred at or before April 15, with the report submitted to the FDA on April 30.

The analyst provided context showing that hepatic failure cases have occurred with other GLP-1 drugs. Mounjaro reported 30 cases and Zepbound 2 cases, while Ozempic showed 33 cases and Wegovy 15 cases. For broader serious hepatic events, Mounjaro and Zepbound combined showed 311 cases versus approximately 105 million prescriptions since the third quarter of 2018, while Ozempic and Wegovy combined reported 447 cases versus approximately 150 million prescriptions over the same period.

Raffat commented that "we cannot look at this single liver case in a silo … and such cases do tend to occur on other GLPs as well because of various confounding factors."

The analyst noted that Foundayo’s liver profile has been established across multiple trials, including the 2,800-patient ACHIEVE-4 study, which investigated hepatic safety at the FDA’s request and observed no hepatic safety signal.

However, Raffat stated that "onus is on LLY to ensure that proper and expedient adjudication of each of such liver cases is being done commercially to avoid any confusion." He cited background concerns stemming from liver toxicity issues with other oral GLP-1 molecules from Pfizer and some ALT elevations in earlier Foundayo trials.