Zealand Pharma shares drop 25% after a quarter of patients quit obesity drug trial

COPENHAGEN - Zealand Pharma's shares tumbled as much as 25% on Monday after trial data for its injectable obesity drug survodutide showed high rates of patients quitting treatment due to side effects, despite some encouraging results in those with liver disease.

The Danish drugmaker's partner Boehringer Ingelheim, which owns the rights to solely develop and commercialise survodutide, presented late-stage data from two studies of the drug over the weekend at a medical conference.

The market for obesity drugs is expected to cross $100 billion by 2030 and is becoming increasingly competitive, with investors focusing on safety, and benefits from newer drugs that go beyond weight loss numbers.

Zealand's shares, down 47% year-to-date, were the biggest fallers on Europe's Stoxx 600 index on Monday, wiping nearly 6 billion Danish crowns (about $900 million) from the company's market capitalisation of $3.6 billion, based on Thursday's closing price.

"The tolerability profile has disappointed," said HSBC analyst Rajesh Kumar, who does not cover Zealand stock. He added that the data did not give larger rivals like Novo Nordisk and Eli Lilly reason to lose sleep.

Novo's shares were 2.9% lower. Lilly's jumped 4% premarket, driven by compelling new data for its next-generation obesity drug, retatrutide.

TOLERABILITY ISSUES DUE TO 'RIGID' DOSING

Nearly one in four patients, or 25%, taking the highest 6-milligram dose of survodutide stopped treatment due to side effects, with about one in five dropping out specifically because of gastrointestinal problems, the data showed.

Novo's Wegovy and Lilly's Zepbound showed dropout rates of 7% and 6%, in their respective trials.

Analysts said that the issues were partly due to the rigid dosing schedule used in both studies, one with overweight or obese patients and the other with liver disease patients. While more flexibility to lower doses was introduced, roughly three in four patients had less than three months of treatment period remaining by then.

Boehringer is investing in additional studies to address tolerability, including how to adjust doses, and switch patients from other GLP-1 drugs.

Analysts attributed an unusually high placebo weight loss, of 5.4%, to patients seeking out marketed treatments despite being part of the study.

JPMorgan said the issue was not unique to survodutide, reflecting a structural challenge for newer treatments being tested as approved GLP-1 drugs become more accessible.

SILVER LINING

Jefferies analysts said that data from the group of liver disease patients was "perhaps the silver lining," and could support a differentiated role for the drug.

Up to 84.2% of patients showed a liver fat reduction of at least 30%, compared with 24.3% on a placebo after 48 weeks.

Barclays analysts, however, warned that the commercial success of a drug that must be taken long-term for a metabolic or liver condition would be determined by whether patients can stay on the treatment.

(Reporting by Stine Jacobsen, Bhanvi Satija and Maggie Fick; Editing by Anna Ringstrom and Emelia Sithole-Matarise, Kirsten Donovan)

Copyright Reuters or USA Today Network via Reuters Connect

This story was originally published June 8, 2026 at 7:33 AM.