Rhythm Pharma knocked off stride as mixed PhIII obesity data for its sole big drug look ‘meh’ to many
Just a few weeks after Rhythm Pharmaceuticals $RYTM snagged an FDA OK for setmelanotide in 3 rare genetic disorders that trigger obesity, the biotech is struggling to make a good case for a crucial market expansion.
Rhythm CEO David Meeker spotlighted the positive data at hand for Bardet-Biedl syndrome and Alström syndrome, two other ailments that trigger an insatiable hunger. But their 3 patients with Alström syndrome all failed the primary endpoint in the study while the BBS efficacy rate dwindled significantly from its Phase II results, dragging down the overall results that left investors and analysts wondering just how big this success really was.
Altogether 34.5% of the 31 patients in the tiny study hit the key endpoint of at least a 10% drop in weight. The study also succeeded on secondary endpoints.
Stifel’s Derek Archila has been tracking Rhythm’s progress, and he had been expecting the biotech to hit a higher threshold on success. But doing some quick back-of-the-envelope math, he figured about 40% of the BBS patients hit the endpoint, giving the biotech a shot at a new market indication worth about $390 million in peak sales.
“While at first blush these results may appear mediocre (our base case was a 40-50%) there are a few key factors to consider,” he wrote Tuesday morning, highlighting the AS flop as well as a possible confounding factor in recruiting adolescents for the study, which might have been weighted against success.
Phil Nadeau also highlighted the positive.
While the BBS responder rate in the Ph III (39%) fell below that seen in the Ph II (67%), any improvement in weight combined with the dramatic reductions in hunger score demonstrated in Phase III is meaningful for these patients, who typically experience ongoing weight gain over time associated with debilitating hyperphagia
The “meh” overall results, though, explain the 5% drop in share price this morning. But Rhythm execs are pushing ahead.
“(T)hese results reinforce the potential value of the MC4R pathway as a therapeutic target for some rare genetic diseases of obesity and underscore our belief that obesity is a complex, multifactorial disease,” said Murray Stewart, the CMO at Rhythm.