Ipsen withdraws NDA for rare bone disease treatment less than 3 months after winning priority review
After winning priority review for its ultra-rare bone disease program at the end of May, Ipsen made an abrupt about-face Friday.
Ipsen withdrew its NDA for palovarotene following discussions with the FDA indicating additional data analyses would be needed from two pivotal trials, the Paris biotech announced. The move came as a surprise to some as Ipsen had made strides to resolve issues stemming from a partial clinical hold in 2019 and a failed futility test soon after.
“Unfortunately, as there is no regulatory mechanism to ‘pause’ the current ongoing review process, we have taken the decision to withdraw the NDA for palovarotene to undertake the additional analyses and evaluation needed, with plans to resubmit the data for palovarotene as soon as possible,” Ipsen R&D chief Howard Mayer said in a statement.
News of the withdrawal resulted in Ipsen shares sinking about 10% on the Euronext Paris exchange.
Jefferies analyst Peter Welford, who has been following the ongoing palovarotene saga, wrote to investors he didn’t see this withdrawal coming. In a note out Friday morning, he alluded to potential issues with comparing Phase III data to natural history studies, as these were slated to be a focus of an upcoming adcomm.
Whenever Ipsen decides to re-file — a move that could come as soon as the fourth quarter, Welford wrote — it may see an expedited priority review process because the FDA is already familiar with the case. Welford had pegged peak sales for the program at $180 million annually, assuming a 2021 US approval, and Friday’s move doesn’t change that projection.
“This setback is unlikely to improve current sentiment, with the overhang from uncertain timing and impact of Somatuline generic competition likely to persist,” Welford wrote.
Researchers had been developing the candidate to try to prevent new bone growth associated with fibrodysplasia ossificans progressiva and multiple osteochondromas. Ipsen took on the drug following a $1 billion-plus acquisition of the Canadian biotech Clementia Pharmaceuticals in February 2019, who had repurposed it for the bone conditions after Roche punted on emphysema trials.
In December 2019, regulators slapped Ipsen with a partial hold on the dosing of patients 14 and under in a Phase II and Phase III study. The hold resulted from reports of “early growth plate closure” in pediatric FOP patients treated with palovarotene, a condition that can severely stunt a child’s growth.
Then, in January 2020, the company’s independent monitoring board said the program failed a Phase III futility test, resulting in Ipsen deciding to pause dosing in all remaining pediatric patients from that trial as well as in Phase II extension studies. Dosing resumed for patients 14 and up a few months later after Ipsen amended certain protocols, but Ipsen ended up scrapping a trial for what would have been their largest market, Welford wrote at the time.
Ipsen had been hoping to turn the tide after winning priority review for palovarotene back in May, and appeared confident enough to return to the dealmaking front with two deals this summer.
In July, the biotech shelled out $28 million upfront with up to $335 million promised milestones for IRLAB’s mid-stage candidate for levodopa-induced dyskinesia, a condition related to Parkinson’s disease. And at the beginning of August, Ipsen spent $20 million upfront and put up $1 billion in potential milestones for exclusive options to two of Exicure’s discovery-stage treatments for Huntington’s disease and Angelman syndrome.
Social image: David Loew, Ipsen CEO