Ligand Pharmaceuticals has licensed its clinical-stage DARA (dual acting receptor antagonist of angiotensin and endothelin receptors) program to Retrophin in return for a $1 million up-front payment, and potentially over $75 million in milestones and 9% royalties. The firm says Retrophin plans to develop DARA for orphan indications of severe kidney disease, and initially focal segmental glomerulosclerosis (FSGS). The firm in addition aims to carry out proof-of-concept studies in resistant hypertension and diabetic nephropathy.
“An estimated 50,000 patients in the U.S. are afflicted with FSGS,” remarks Martin Shkreli, Retrophin CEO. “DARA may help patients who are at a high risk of losing their kidneys to their diseases by delaying the progression and reversing severe markers of kidney damage such as proteinuria. We will work to advance DARA into a pivotal trial as quickly as possible.”
Ligand took on the DARA program through its acquisition of Pharmacopeia in 2008. The compound selectively blocks angiotensin II and endothelin I at their receptors. Phase IIb studies for the hypertension indication were completed in 2009, and demonstrated that in comparison with irbesartan, treatment using DARA led to a significantly greater reduction in blood pressure.
Retrophin is developing a pipeline of fusion protein candidates for the potential treatment of Duchenne muscular dystrophy (DMD), spinal muscular atrophy, cystic fibrosis, and myotubular myopathy. A clinical trial with lead in-house DMD protein replacement therapy candidate RE-001 is expected to start this year.