The discovery that artificial strands of RNA can block the prduction of specific proteins by binding their messenger RNA templates and preventing their translation won researchers Andrew Fire and Craig Mello the Nobel Prize for medicine in 2006 .
The breakthrough also attracted the attention of seveal drugmakers – Roche, AstraZeneca , Dainippon and Pfizer to name a few - which suggested that being able to selectively “silence” gene expression had considerable therapeutic and market potential.
Since then, however, technical difficulties have started to cool Big Pharma interest with Swiss drugmaker Novartis being just the latest firm to halt its RNAi development programme citing the difficulty of delivering the artificial RNA strands as the reason for its decision.
The echoes statements by Novartis' Swiss neighbour Roche, which sold its RNAi programme to Arrowhead in 2011 , and US counterpart Merck & Co, which divested its gene silencing business to Alnylam for $175m in early January.
Novartis also said its decision to halt development of RNAi-based drugs was related to their limited therapeutic utility, explaining in a statement that “the current range of medically relevant targets where siRNA may be used is quite narrow.”
Bullish on Science
Despite the negativity from Wall Street and Big Pharma, smaller, niche companies are continuing to bring their developing therapeutics to market.
Kleanthis Xanthopoulos, president and CEO of Regulus Therapeutics, told in-Pharmatechnologist.com the recent slip in share prices comes after his company and others like it accumulated “a tremendous amount of shareholder value” over the last two years.
Xanthopoulos noted that Novartis’ RNA therapeutics outfit had “a relatively small focus…I think they didn’t have the critical mass or patience to get through.”
“I think we need to separate market reaction from science,” he added, noting Regulus has “never been more bullish about our science.”
He also explained how Regulus, alongside Alnylam and Isis Pharmaceuticals, are driving the future of RNA therapeutics with their microRNA, RNAi and anti-sense technology platforms, respectively.
Regulus expects to have three of its potential drug candidates developed through its microRNA platform in the clinic by 2015.