Ora is a US-based global, full-service ophthalmic clinical research and product development company.
As part of the deal, Ora will lead the clinical development of PRT2671, and the companies will share the development expenses until proof-of-concept is established, while Portola retains decision making oversight of the program.
Portola chief executive officer William Lis said: "This collaboration for PRT2761 is part of a strategy that allows us to advance early-stage compounds outside of our key focus on thrombosis and hematologic cancer with innovative companies that have the expertise and resources to develop these agents to proof-of-concept."
The company said that the inhibition of Syk may more completely prevent activation of mast cells in ocular allergy and, therefore, a Syk inhibitor could represent a promising therapeutic option.
Ora president and chief executive officer Stuart Abelson said: "Portola’s highly specific Syk inhibitor PRT2761 has the potential to deliver rapid onset of action and comprehensive treatment of both signs and symptoms of ocular allergy, including redness, inflammation, swelling and itching.
"We are impressed by its properties and preclinical data, which demonstrated activity in reducing conjunctival redness and swelling, a key clinical sign of allergic conjunctivitis that is not adequately treated by existing therapies."