DESCRIPTION OF BUSINESS

Organization and Description of Business

In this Quarterly Report on Form 10-Q, unless the context requires otherwise, the terms “we”, “our”, “us”, “Retrophin” and the “Company” refer to Retrophin, Inc., a Delaware corporation, as well as our direct and indirect subsidiaries. We are a fully integrated biopharmaceutical company with approximately 130 employees headquartered in San Diego, California dedicated to delivering life-changing therapies to people living with rare diseases who have few, if any, treatment options. Our approach centers on our pipeline, featuring clinical-stage assets and pre-clinical discovery programs targeting rare diseases with significant unmet medical needs. Our research and development efforts are supported by revenues from the Company's marketed products, Chenodal^®, Cholbam^®and Thiola^®. In addition we regularly evaluate and, where appropriate, act on opportunities to expand our product pipeline through licenses and acquisitions of products in areas that will serve patients with serious, catastrophic or rare diseases and that we believe offer attractive growth characteristics.

Products on the Market:

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Chenodal^® (chenodeoxycholic acid) is approved in the United States for the treatment of patients suffering from gallstones in whom surgery poses an unacceptable health risk due to disease or advanced age. Chenodal has also been the standard of care for cerebrotendinous xanthomatosis (“CTX”) patients for more than three decades and the Company is currently pursuing adding this indication to the label.


•	Cholbam^® (cholic acid) is approved in the United States for the treatment of bile acid synthesis disorders due to single enzyme defects and is further indicated for adjunctive treatment of patients with peroxisomal disorders.


•	Thiola^® (tiopronin) is approved in the United States for the prevention of cysteine (kidney) stone formation in patients with cystinuria.

Product Candidates:

Sparsentan, also known as RE-021, is an investigational therapeutic agent which acts as both a potent angiotensin receptor blocker (“ARB”), as well as a selective endothelin receptor antagonist (“ERA”), with in vitro selectivity toward endothelin receptor type A. We have secured a license to sparsentan from Ligand Pharmaceuticals, Inc. and Bristol-Myers Squibb Company (who referred to it as DARA). We are developing sparsentan as a treatment for focal segmental glomerulosclerosis ("FSGS"), which is a leading cause of end-stage renal disease and Nephrotic Syndrome (“NS”). There are no U.S. Food and Drug Administration ("FDA") approved pharmacological treatments for FSGS and the off-label armamentarium is limited to ACE/ARBs, steroids, and immunosuppressant agents, which are effective in only a subset of patients. We estimate that there are at least 40,000 FSGS patients in the United States. We have completed enrollment for our DUET Phase 2 clinical study of sparsentan for the treatment of FSGS and we anticipate having a top line data read out in the third quarter of 2016. Depending on the robustness of the data obtained in the DUET study, we may be able to support an application for accelerated approval for sparsentan on the basis of proteinuria as a surrogate endpoint. Sparsentan was granted orphan drug designation in the U.S. and EU in January and November 2015, respectively.

We are developing RE-024, a novel small molecule, as a potential treatment for pantothenate kinase-associated neurodegeneration ("PKAN"). PKAN is a genetic neurodegenerative disorder that is typically diagnosed in the first decade of life. Consequences of PKAN include dystonia, dysarthria, rigidity, retinal degeneration, and severe digestive problems. PKAN is estimated to affect 1 to 3 persons per million. There are currently no viable treatment options for patients with PKAN. RE-024 is a phosphopantothenate prodrug therapy that aims to restore levels of this key substrate in PKAN patients. Certain international health regulators have approved the initiation of dosing RE-024 in PKAN patients under physician-initiated studies in accordance with local regulations in their respective countries. The Company filed a Investigational New Drug application ("U.S. IND") for RE-024 with the FDA in the first quarter of 2015 to support the commencement of a Company-sponsored Phase 1 study, which was successfully completed during 2015. RE-024 was granted orphan drug designation by the FDA in May 2015 and was granted fast track designation by the FDA in June 2015. On February 24, 2016, we announced RE-024 was granted orphan drug designation from the European Commission. The Company continues discussions with the FDA and the European Medicines Agency ("EMA") regarding the initiation of a potential registration-enabling efficacy trial in PKAN patients.

L-UDCA is a liquid formulation of ursodeoxycholic acid being developed for the treatment of a rare liver disease called primary biliary cholangitis (PBC). Retrophin expects to file a New Drug Application with the FDA in 2017 and, if approved, plans to make L-UDCA commercially available to the subset of PBC patients who have difficulty swallowing. There are no liquid formulations of ursodeoxycholic acid currently approved by the FDA.

RE-034 is a synthetic hormone analog of the first 24 amino acids of the 39 amino acids contained in adrenocorticotropic hormone ("ACTH") incorporated into a novel formulation developed by the Company. RE-034 exhibits similar physiological actions as endogenous ACTH by binding to all five melanocortin receptors (pan-MCR), resulting in its anti-inflammatory and immunomodulatory effects. Retrophin has successfully manufactured RE-034 at proof-of-concept scale using a novel formulation process that allows modulation of the release of the active ingredient from the site of administration. The Company is exploring strategic options for development of RE-034, including the evaluation of external partnership and out-licensing opportunities.

Preclinical:

NGLY1

The Company entered into a research collaboration with the Grace Science Foundation and the Warren Family Research Center for Drug Discovery and Development at the University of Notre Dame for the development of a novel therapeutic for patients with NGLY1 deficiency, a rare genetic disorder. NGLY1 deficiency is believed to be caused by a deficiency in an enzyme called N-glycanase-1, which is encoded by the gene NGLY1. The condition is characterized by a variety of symptoms, including global developmental delay, movement disorder, seizures, and ocular abnormalities. Under this collaboration, the Grace Science Foundation will provide support and funding to Retrophin to enable discovery efforts that aim to validate and address a new molecular target that may be relevant to NGLY1 deficiency. The Warren Family Research Center for Drug Discovery and Development at the University of Notre Dame will provide funding and in-kind research support to help Retrophin advance this program.