FDA needs three more months to review Roche's SMA drug — giving Biogen, Novartis some relief
The first oral drug for spinal muscular atrophy was widely expected to be approved by the end of May after priority review. But its developers at Roche, PTC Therapeutics and the SMA Foundation will now have to wait for three more months.
The FDA said they need the extra time to review a bunch of new data Roche has recently submitted, including results from a trial involving older patients. The good news is that regulators have identified “no substantive review issues” to date, according to a PTC statement.
Cowen analysts called the decision to augment the data package — which could “ensure the broadest potential label” — prudent, even if it means a delay.
In so doing they could capture a bigger real-world patient population as risdiplam takes on the two therapies currently on the market, Biogen’s Spinraza and Novartis’ Zolgensma. Notably, Novartis’ gene therapy is only approved for infants under 2, although the pharma giant is looking to expand beyond that.
Two pivotal studies form the bedrock of the NDA. FIREFISH is an open-label trial in infants with type 1 SMA, while SUNFISH is placebo-controlled and recruited patients aged 2 to 25 years with types 2 or 3 SMA. Both are designed to contain two parts, first to determine a dose and assess safety and then confirm efficacy.
Roche’s supplementary material featured Part 2 of SUNFISH, in which risdiplam hit the primary endpoint on motor function after 1 year of treatment. It’s also working toward filing with the EMA, which requested data from both parts of the studies, by mid-year, following submissions in Indonesia, Taiwan, Chile, Brazil, South Korea and Russia.
SVB Leerink analysts point out that Biogen and Ionis (which developed the antisense oligonucleotide) should reap the majority of the benefit from the delay, however modest.
“We estimate $36M in 2020 risdiplam sales, compared to $2.2B and $660M in Spinraza and Zolgensma sales, respectively,” they wrote in a note.
In the long run, though, risdiplam is expected to become a serious contender to a three-way rivalry given its ease of dosing, with Cowen pegging peak sales at $3.2 billion. By modifying how the SMN2 gene is spliced, the drug increases functional SMN protein levels in both the central nervous system and peripheral tissues.
Pricing could also come into play, as Novartis has the world’s most expensive, $2.1 million drug in Zolgensma and Biogen charges $750,000 for the loading dose of Spinraza and then about $375,000 annually for life. Bill Anderson, CEO of Roche’s pharma group, has said he plans to “underwhelm” with risdiplam pricing.