Rhythm Pharmaceuticals, Inc., a commercial-stage biopharmaceutical company, focuses on the rare neuroendocrine diseases. The company's lead product candidate is IMCIVREE (setmelanotide), a rare melanocortin-4 receptor for the treatment of pro-opiomelanocortin (POMC), proprotein convertase subtilisin/kexin type 1, leptin receptor (LEPR) deficiency obesity, and Bardet-Biedl and Alström syndrome. It is in Phase 3 clinical trials for treating POMC or LEPR heterozygous deficiency obesities, steroid receptor coactivator 1 deficiency obesity, SH2B1 deficiency obesity, MC4 receptor deficiency obesity, and other MC4R disorders. The company has licensing agreements with LG Chem, Ltd; Ipsen Pharma S.A.S; Camurus; RareStone Group Ltd.; joint research collaboration with Axovia Therapeutics for developing in bardet-biedl syndrome; and LG Chem, Ltd. The company was formerly known as Rhythm Metabolic, Inc. and changed its name to Rhythm Pharmaceuticals, Inc. in October 2015. Rhythm Pharmaceuticals, Inc. was founded in 2008 and is headquartered in Boston, Massachusetts.

Soleno Therapeutics, Inc., a clinical-stage biopharmaceutical company, focuses on the development and commercialization of novel therapeutics for the treatment of rare diseases. Its lead candidate is Diazoxide Choline Extended-Release tablets, a once-daily oral tablet, which is in Phase III clinical trials for the treatment of Prader-Willi Syndrome. The company was formerly known as Capnia, Inc. and changed its name to Soleno Therapeutics, Inc. in May 2017. Soleno Therapeutics, Inc. was incorporated in 1999 and is based in Redwood City, California.

Travere Therapeutics, Inc., a biopharmaceutical company, identifies, develops, and delivers therapies to people living with rare kidney and metabolic diseases. Its products include FILSPARI (sparsentan), a once-daily, oral medication designed to target two critical pathways in the disease progression of IgA Nephropathy (endothelin 1 and angiotensin-II); and Thiola and Thiola EC (tiopronin tablets) for the treatment of cystinuria, a rare genetic cystine transport disorder that causes high cystine levels in the urine and the formation of recurring kidney stones. The company's clinical-stage programs consist of Sparsentan, a novel investigational product candidate, which has been granted Orphan Drug Designation for the treatment of focal segmental glomerulosclerosis in the U.S. and Europe; and Pegtibatinase (TVT-058), a novel investigational human enzyme replacement candidate being evaluated for the treatment of classical homocystinuria. It has a cooperative research and development agreement with National Institutes of Health's National Center for Advancing Translational Sciences and Alagille Syndrome Alliance for the identification of potential small molecule therapeutics for Alagille syndrome. The company was formerly known as Retrophin, Inc. and changed its name to Travere Therapeutics, Inc. in November 2020. Travere Therapeutics, Inc. was incorporated in 2008 and is headquartered in San Diego, California.

Reneo Pharmaceuticals, Inc., a clinical-stage pharmaceutical company, focuses on the development and commercialization of therapies for patients with rare genetic mitochondrial diseases. The company's lead product candidate is REN001, a potent and selective agonist of the peroxisome proliferator-activated receptor delta that is in clinical development for genetic mitochondrial diseases comprising primary mitochondrial myopathies and long-chain fatty acid oxidation disorders. Reneo Pharmaceuticals, Inc. was incorporated in 2014 and is headquartered in Irvine, California.

Quince Therapeutics, Inc., a biopharmaceutical company, focuses on acquiring, developing, and commercializing therapeutics for patients with debilitating and rare diseases. The company's lead asset candidature comprises EryDex for the treatment of rare pediatric neurodegenerative disease, including A-T, an inherited autosomal recessive neurodegenerative and immunodeficiency disorder caused by mutations in ATM gene. Its AIDE technology platform, a drug/device combination platform that uses an automated process to encapsulate a drug into a patient's own red blood cells, as well as consists of an automated equipment the RCL, a sterile single-use consumable treatment kit comprising EryKit, Syringe Kit, drugs, and process solutions. The company was formerly known as Cortexyme, Inc. and changed its name to Quince Therapeutics, Inc. in August 2022. Quince Therapeutics, Inc. was incorporated in 2012 and is headquartered in South San Francisco, California.

RAPT Therapeutics, Inc., a clinical-stage immunology-based biopharmaceutical company, focuses on discovery, development, and commercialization of oral small molecule therapies for patients with unmet needs in oncology and inflammatory diseases in the United States. The company's lead inflammation drug candidate is zelnecirnon (RPT193), a C-C motif chemokine receptor 4 (CCR4) antagonist that selectively inhibit the migration of type 2 T helper cells into inflamed tissues. Its lead oncology drug candidate is tivumecirnon (FLX475), an oral small molecule CCR4 antagonist that is in the Phase 1/2 clinical trial to investigate as a monotherapy and in combination with pembrolizumab in patients with advanced cancer. The company was formerly known as FLX Bio, Inc. and changed its name to RAPT Therapeutics, Inc. in May 2019. RAPT Therapeutics, Inc. was incorporated in 2015 and is headquartered in South San Francisco, California.

Unity Biotechnology, Inc., a biotechnology company, engages in the research and development of therapeutics to slow, halt, or reverse diseases of aging. The company's lead drug candidate includes UBX1325, which is Phase 2 clinical trial for the treatment of age-related diseases of the eye, including diabetic macular edema, age-related macular degeneration, and diabetic retinopathy. It also develops UBX1967 for the treatment of ophthalmologic diseases; UBX2048, a Tie2/VEGF bispecific; UBX2050, a human anti-Tie2 agonist monoclonal antibody for the treatment of eye diseases; and UBX2089, a a-Klotho hormone drug candidate for multiple neurology indications. The company was formerly known as Forge, Inc. and changed its name to Unity Biotechnology, Inc. in January 2015. Unity Biotechnology, Inc. was incorporated in 2009 and is headquartered in South San Francisco, California.

Eiger BioPharmaceuticals, Inc., a commercial-stage biopharmaceutical company, focuses on the development and commercialization of targeted therapies for rare and ultra-rare diseases in the United States and internationally. Its lead product candidate is Lonafarnib, an orally bioavailable, small molecule, which is in Phase III clinical trials to treat hepatitis delta virus infection. The company's product candidate also include Lambda, which targets type III interferon receptors that has completed Phase II clinical trials; Lonafarnib for the treatment of progeria and progeroid laminopathies; and Avexitide for the treatment of congenital hyperinsulinism, as well as has completed Phase II clinical trials to treat post-bariatric hypoglycemia. Eiger BioPharmaceuticals, Inc. was founded in 2008 and is headquartered in Palo Alto, California.