Ablynx regained worldwide rights from Pfizer to develop and commercialize Nanobodies targeting TNF-alpha. These rights include Phase II-stage ATN-103 for treating rheumatoid arthritis (RA) and Phase II-ready PF-05230905. Ablynx has not yet decided how to proceed with these candidates and expects to first undertake a detailed review of the programs.
Pfizer obtained these Nanobodies in 2009 when paid about $68 billion to acquire Wyeth, which had inked a deal with Ablynx in 2006. With the termination of the agreement, Pfizer returned all licensed rights including intellectual property (IP) and is also handing over to Ablynx certain Pfizer IP and know-how relating to the anti-TNF-alpha programs. Additionally, Ablynx will have access to Pfizer's existing clinical trial supplies of ATN-103 and PF-05230905 as well as assay methods and manufacturing processes for use in future development activities.
In return for these rights and assets, if an anti-TNF-alpha Nanobody is approved, Ablynx will share milestone payments it receives from any third party licensee with Pfizer, up to a capped amount of $50 million, as well as pay a royalty on sales of such products.
Since 2009, a total of 456 subjects have reportedly been recruited in clinical trials with ATN-103 to evaluate the safety, pharmacology, and clinical effectiveness in single- and multiple-ascending dose studies. Two single-dose studies in healthy volunteers have been completed in Japan and the U.S., and two multiple-dose studies in patients with active rheumatoid arthritis adding ATN-103 or placebo to a methotrexate background were conducted in Japan and North America/rest of the world.
First clinical proof-of-concept was generated for ATN-103 in May 2011. A dose of 80 mg administered as a single subcutaneous injection every four weeks to patients with active RA on a stable background of methotrexate resulted at week 16 in a statistically significant improvement of disease scores.
This study recruited 253 patients in North America/rest of the world. No dose-limiting toxicity was observed and clinical side effects did not increase significantly upon increased dosing, according to Ablynx. Two percent of subjects treated with ATN-103 were positive for neutralizing antidrug-antibodies, and there were no additional observed effects on PK/PD.
In February 2010, Pfizer started a long-term safety study for ATN-103, which is an open-label extension study of the Phase II trials, that is currently ongoing at 67 centers worldwide. This trial is expected to complete during the first half of 2012.
In November 2010, Ablynx recieved a $3 million milestone fee with Pfizer's start of a Phase I study with PF-05230905. Ablynx says the trial has been completed, but results have not been reported.
Ablynx also received milestones for ATN-103 from Wyeth, totaling $7 million: $3 million for the start of Phase I and $4 million for the start of Phase II. At the time Ablynx inked the deal with Wyeth, in November 2009, it stood to make up to $212.5 million for the succesful development and commercialization of multiple products.