By Kamal Choudhury
March 16 (Reuters) – Rhythm Pharmaceuticals said on Monday its experimental obesity drug in patients with rare genetic conditions did not meet the main goal of a late-stage trial.
Shares of the Boston-based company fell over 5% in extended trading.
The trial was testing whether the drug, setmelanotide, could meaningfully reduce body mass index, or BMI, compared to a placebo over 52 weeks in patients whose obesity is caused by specific genetic mutations.
The four patient groups in the trial each carried a different gene variant — POMC/PCSK1, LEPR, SRC1, and SH2B1 — that disrupts a biological pathway in the brain known to regulate hunger and body weight.
None of the four groups met the bar the company had set before the trial began.
Rhythm CEO David Meeker acknowledged the results in a conference call, saying it had been “a long road ending not exactly where we had hoped,” but pointed to encouraging signals in two of the four patient groups as a reason for cautious optimism.
Rhythm said, however, that follow-up analysis showed the drug did achieve statistically significant BMI reductions in patients with POMC/PCSK1 and SRC1 gene variants who completed 52 weeks of treatment.
The company said further development in these genetic groups will be carried out using its next-generation drug candidates, bivamelagon and RM-718.
A key factor that hurt the results was an unusually high dropout rate, with between 40% and 60% of patients quitting the trial before it ended.
“Patient decision was the most common reason for patients on placebo, and adverse events were the most common reason for patients on setmelanotide,” Meeker cited as the reasons for patients quitting.
Meeker said the company was “running against the emergence of GLP-1s,” suggesting some patients may have left to try popular weight-loss drugs.
He added that the company would not seek regulatory approval based on the current data.
(Reporting by Kamal Choudhury in Bengaluru; Editing by Alan Barona)
Comments