With $1.1bn in cash plus revenue from its existing commercial products and royalties from Roche’s sales of newly approved Evrysdi to invest in R&D, PTC Therapeutics may achieve profitability in 2023.

Jeffrey Aronin, who presided over Marathon Pharmaceuticals during a drug-pricing kerfuffle that drew congressional scrutiny, has built a portfolio of new drug companies at Paragon Biosciences.

Patient-driven drug development meets the old saying of "where there's a will, there's a way" in China, potentially the world's largest market for rare disease treatments.

Legislation pending in US House Energy and Commerce Committee would exempt drugs treating diseases with less than 200,000 patients from needing to justify price increases.