Antisense-drug developer Isis Pharmaceuticals and GlaxoSmithKline (GSK) have forged a collaboration to develop drugs for rare diseases that could earn the Carlsbad, California–based biotech up to $1.5 billion dollars in licensing fees and milestones. London-based GSK will pay Isis $35 million upfront and up to $20 million for each of the six programs, which Isis has agreed to develop to proof of concept. Isis will apply its antisense-drug discovery platform to work on novel targets in new therapeutic areas, including infectious diseases and some conditions causing blindness. “The deal is emblematic of deals that financially sound companies can enter into,” says Isis CFO and COO Lynne Parshall. “We can rely on longer-term royalties over the course of a drug's lifetime rather than bigger upfront licensing fees,” says Parshall. Isis' pact with the pharma comes on the heels of encouraging phase 3 trial data for the cholesterol-reducing antisense drug mipomersen that Isis is developing with its partner Genzyme (Nat. Biotechnol. 28, 295–297, 2010). The latest agreement underscores GSK's interest in nucleic acid–based therapeutics notes Lindsay Meyer, a senior consultant with Deloitte Recap, San Francisco. She highlights GSK's recent alliances with Regulus of Carlsbad, California, and Prosensa, of Leiden, The Netherlands, and earlier with Santaris in Hoersholm, Denmark. Isis, however, stands to benefit more than other companies that have licensed their RNA-based therapeutics to GSK, Meyer believes.