Roche, Zealand's obesity drug shows up to 10.7% weight loss in mid-stage trial

By Kamal Choudhury and Sriparna Roy

March 5 (Reuters) - Roche ROG.S said on Thursday its experimental obesity drug, which it is developing with Denmark's Zealand Pharma ZELA.CO, helped patients lose up to 10.7% of their body weight in a mid-stage study.

In the 493-patient trial, the patients on the drug, petrelintide, lost far more weight over 42 weeks than those given placebo, who reported a 1.7% decline.

Roche gained access to petrelintide through a collaboration and licensing deal worth up to $5.3 billion signed last year, giving the Swiss drugmaker shared development rights to the obesity therapy which mimics a hormone called amylin that is co-secreted with insulin.

The mid-stage data follows results for Eli Lilly's LLY.N amylin-mimicking drug candidate eloralintide, which helped patients lose as much as 20.1% of their weight after 48 weeks in a mid-stage study.

Analysts have previously estimated that weight loss in the range of 12% to 13% after adjusting for placebo would make Zealand's petrelintide competitive with Lilly's eloralintide.

"The weight loss efficacy is clearly below what we saw for eloralintide — but it’s also really hard to compare these trials, because females respond so much better to treatment," said Morningstar analyst Karen Andersen, who noted that women made up 53% of Zealand’s trial versus 78% in Lilly’s.

Eloralintide probably still has an efficacy edge over rivals, even when adjusting for the gender imbalance in its mid-stage trial, said Andersen.

On a call with analysts, a Zealand chief medical officer David Kendall said female participants in the trial achieved about six percentage points more weight loss than male participants on a placebo-adjusted basis.

The weight-loss drug market is surging, with biotech firms racing to win their share in a sector dominated by popular treatments Novo Nordisk's Wegovy NOVOb.CO and Eli Lilly's LLY.N Zepbound.

Unlike Wegovy and Zepbound — which target the GLP-1 hormone to reduce appetite — amylin-based drugs, such as petrelintide, activate receptors in the brain and slow gastric emptying with the potential for less severe side effects and preservation of muscle.

Zealand expects to start a late-stage trial this year.