Roche’s bid to rival Biogen and Novartis in treating spinal muscular atrophy (SMA) got a lift on Monday when the Swiss drugmaker said its drug risdiplam improved motor function of patients in a key study. Roche, which plans to seek approval for the investigational medicine this year, said its SUNFISH trial demonstrated statistically significant improvements in patients aged 2-25 years with Type 2 or 3 SMA, compared to a placebo. Biogen’s Spinraza, approved in 2016, lists at $750,000 in year one and $375,000 thereafter, while Novartis’s Zolgensma is the costliest one-time treatment at $2.1 million. […]