Another quarter has brought another timely reminder of how tough it is for biotechs to launch drugs without the assistance of a bigger partner with muscle. The RNAi product Onpattro, launched in August for polyneuropathy caused by hATTR amyloidosis, managed third-quarter sales of just $0.5m, missing expectations and sending its maker, Alnylam, down 12% yesterday. Consensus sellside forecasts compiled by EvaluatePharma have the drug selling $18m this year, something that now must surely be out of reach, notwithstanding Alnylam’s assurances that 125 US patient start forms had been received within seven weeks of Onpattro’s introduction. Barring outliers, biotech solo launches tend to disappoint the more optimistic investors, especially if a big pharma competitor is already on the market, as demonstrated recently by Clovis’s Rubraca – though interestingly not by Tesaro’s Zejula. Vantage had suggested in August that Alnylam would find going it alone tough (After Alnylam’s solo maiden launch, here comes the tricky bit, August 13, 2018). Goldman Sachs recently pointed out that rare disease drugs specifically tend to have disappointing launches, barring such big biotech products as Biogen’s Spinraza and Vertex’s cystic fibrosis franchise.