Roche has solidified the promising outlook of its spinal muscular atrophy (SMA) drug risdiplam, which has just met the primary endpoint in another pivotal trial.
The positive topline results from part 2 of the FIREFISH study showed that risdiplam hit its primary endpoint – the drug was able to improve infants ability to sit independently for at least five seconds after 12 months of treatment.
The results are significant, given that the study included infants aged one to seven months with type 1 SMA, the most severe form of the muscle-wasting disease.
The positive results in type 1 SMA build on Roche’s earlier studies of risdiplam, evaluating its use in type 2 and type 3 SMA patients. The SUNFISH study demonstrated that, following a year’s treatment with the drug, patients aged two to 25 with SMA type 2/3 had superior Motor Function Measure 32 (MFM-32) scale scores compared to placebo.
On the back of that data, Roche scored a priority review for risdiplam back in November, meaning a final decision on its approval is expected by 24 May 2020.
“This large, global trial confirms the efficacy of risdiplam in an advanced and difficult-to-treat population, including many infants whose disease had already progressed significantly before starting treatment,” said Levi Garraway, Roche’s chief medical officer and head of Global Product Development.
The likelihood of its approval is high – Zuercher Kantonalbank analyst Michael Nawarth said in a note to investors that “we’re almost certain of its approval”, adding that “the sales peak is around 2bn Swiss francs ($2.07bn)”.
Nawarth also predicted that the drug could go on to become the standard treatment for patients with less-acute forms of the disease, that materialise months after birth.
If it does get approval – which is likely – risdiplam will go on to compete in the market with Biogen’s blockbuster antisense-based SMA medicine Spinraza (nusinersen), as well as Novartis’ controversial gene therapy Zolgensma (onasemnogene abeparvovec), which offers a one-shot treatment for the disease.
Both drugs come with a premium price-tag – Biogen’s drug costs $750,000 for the first year of treatment and $375,000 thereafter at US wholesale prices, while Zolgensma’s one-time cost is $2.1m, the highest drug price in the world.
According to Reuters, Roche plans to price risdiplam aggressively to challenge the two highly-priced drugs. CEO of Roche Pharmaceuticals Bill Anderson said the company aims to price risdiplam similar to its haemophilia A medicine Hemlibra, which undercut the price of rival therapies.
“With Hemlibra, we priced at about half of bypassing agent,” Anderson told Reuters, adding that “we aim to underwhelm with our price” of risdiplam.
Risdiplam is a closer competitor to Spinraza, in terms of its target age range and given that Zolgensma is a one-shot therapy.
It could have an advantage over Biogen’s treatment schedule – risdiplam is an orally-active treatment, while Spinraza has to be injected into the spine. However, risdiplam is a daily treatment, while Spinraza is dosed every four months after multiple injections in an initial loading period.