TG Therapeutics, a clinical-stage biopharmaceutical company of New York, N.Y., and Rhizen Pharmaceuticals, a Switzerland-based biopharmaceutical company, have entered into an exclusive global agreement to collaborate on the development and commercialization of Rhizen's lead product candidate, TGR-1202, a novel PI3K delta inhibitor previously referred to as RP5264.

The companies will jointly develop the product on a worldwide basis, excluding India, initially focusing on indications in the area of hematologic malignancies and autoimmune disease. Beyond TGR-1202, Rhizen will contribute backup molecules providing multiple opportunities for TG to develop differentiated therapies against hematologic cancers and autoimmune diseases.

TG Therapeutics will make up-front licensing payments and milestones based on early clinical development, and will be responsible for the costs of clinical development of the products through phase II, after which TG Therapeutics and Rhizen will be jointly responsible for all development costs of the product. Each company maintain an exclusive option, exercisable at specific times during development, for TG Therapeutics to license the rights to TGR-1202, in which case Rhizen would be eligible to receive upfront, development and commercialization milestone payments in addition to milestone payments and royalties tied to net sales of the product, the aggregate of which could exceed $250 million. Rhizen shall maintain rights to manufacture and supply the product to TG Therapeutics, and TG Therapeutics will be responsible for all clinical and regulatory development for TGR-1202 globally.

TGR-1202 is a highly specific, orally available, PI3K delta inhibitor, targeting the delta isoform with nanomolar potency and several fold selectivity over the alpha, beta and gamma isoforms of PI3K. Inhibition of PI3K delta signaling with TGR-1202 has demonstrated robust activity in numerous pre-clinical models and primary cells from patients with hematologic malignancies. An IND for TGR-1202 is expected to be filed by the end of 2012.