Quark Pharmaceuticals said this week that it is has assumed responsibility for conducting a phase IIa trial of its investigational RNAi-based treatment for open-angle glaucoma after amending a licensing deal for the drug with Pfizer.
The drug, PFE-655, comprises siRNAs against a proprietary gene target called RTP-801. In 2006, Pfizer acquired the rights to the target and the drug for certain ocular diseases including diabetic macular edema and wet age-related macular degeneration (GSN 9/28/2006).
In 2011, Quark disclosed that a phase II trial in DME had been halted early after Pfizer determined that PFE-655 was unlikely to produce a therapeutic benefit superior to the current standard of care. As a result, the companies amended their arrangement, shifting the responsibility of running a phase IIb trial, looking at a higher dose of the drug, to Quark. Pfizer was also granted the right to pull out of the licensing deal depending on the study's outcome.
Data from that trial are expected by year end.
Quark said this week that the alliance with Pfizer has been further amended to allow it to run a phase IIa study of PFE-655 for glaucoma in parallel with the phase IIb DME trial.
“Under the amended agreement, should Pfizer assume development and potential commercialization of PF-655 in either or both indications following review of the Phase IIa PF-655 data, Quark will receive option exercise payments and be will eligible to receive development and regulatory milestones specific to each indication, as well as sales milestones and royalties,” Quark said.
The company added that it may also receive additional payments of up to $165 million associated with the further development and market approval of the drug.