BioWorld International Correspondent

LONDON - SR Pharma plc agreed to Europe's first big-ticket deal in the field of RNAi, agreeing to a $95 million plus royalties sublicense with Pfizer Inc., for RTP-801i for treating the wet form of age-related macular degeneration (AMD).

This, Pfizer's first move into RNAi, is part of a much bigger deal with Quark Biotech Inc., of Fremont, Calif., which in-licensed RPT-801i from SR Pharma's subsidiary, Atugen AG, of Berlin, in 2004.

The value of Quark's share of the deal was not disclosed, but in February 2003 Pfizer paid Eyetech Pharmaceuticals Inc. (now owned by OSI Pharmaceuticals) $100 million up front and agreed milestone payments of $195 million, for Macugen, also for treating wet AMD.

"Quark did the deal with Pfizer, but it is for our molecule, and we have a separate agreement with Pfizer," Iain Ross, chairman of SR Pharma, told BioWorld International. "This is an outstanding deal for us, for what is still a preclinical stage product, and it is a huge validation for our RNAi technology."

London-based SR Pharma, which acquired Atugen in a £6.3 million (US$11.9 million) reverse takeover in July 2005, will get an initial payment of $2 million and a milestone payment of $1.5 million when RTP-801i enters Phase I.

Atugen discovered the target gene RTP-801, which is involved in angiogenesis, and developed the RNAi construct to silence it. However, the company did not take it forward in AMD, where it will be applied topically, as the ambition is to be the first to devise a means of delivering RNAi systemically.

"RNAi has been shown to be effective topically, but it really comes into its own with systemic delivery," Ross said. "Atugen has spent seven years working on delivery, and we are on track to move into the clinic next year."

Ross said the German regulators "have taken a positive view," of granting permission for clinical trials of Atugen's products, which will be delivered using the company's proprietary liposomal delivery system. He expects the full preclinical toxicology package in primates to be completed by the end of 2006, paving the way for the first trial in liver cancer next year.

There is considerable interest from potential partners. "The tox package is what people want to see. We will have that ready in January, which may be the trigger for a deal, or it may be that partners will hold out until we reach Phase I," Ross said.