Rhythm's drug shows promise for brain tumor-related weight condition in small study (updated)

Rhythm Pharmaceuticals

04/08/2026 15:06

Adds detail on trial in paragraph 1
Aug 4 (Reuters) - Rhythm Pharmaceuticals RYTM.O said on Tuesday its experimental weekly injectable drug helped reduce body weight in patients with a rare form of obesity caused by damage to the brain, according to preliminary data from an ongoing 11-patient study.

Here are the details:
The mid-stage trial was testing the drug, RM-718, in patients with acquired hypothalamic obesity, a condition that can develop after tumor treatment damages the part of the brain controlling hunger and weight. It is different from common obesity linked to diet and lifestyle.   
Among the enrolled patients, the seven who completed 16 weeks of treatment saw their body mass index - a measure of body fat based on height and weight - fall by an average of 11.6%.
"These encouraging results suggest that RM-718 has the potential to deliver clinically meaningful BMI reductions in patients" with the condition, said Rhythm's CEO David Meeker.
RM-718 works by activating a brain receptor called MC4R, which helps control hunger and metabolism.
The company said the BMI reduction was similar to results seen with its other obesity drugs, once-daily injectable setmelanotide, sold under the brand name Imcivree, and experimental drug bivamelagon, over a similar period.
Two patients stopped treatment with RM-718 due to side effects, including nausea and injection site problems, while one patient withdrew from the trial's extension phase. 
Separately, Rhythm posted second-quarter total revenue of $71.3 million, up 46.9% from $48.5 million a year earlier.

 (Reporting by Kamal Choudhury in Bengaluru; Editing by Vijay Kishore)
 ((Kamal.Choudhury@thomsonreuters.com;))