Apellis Pharmaceuticals, Inc., a commercial-stage biopharmaceutical company, focuses on the discovery, development, and commercialization of therapeutic compounds through the inhibition of the complement system for autoimmune and inflammatory diseases. It offers EMPAVELI for the treatment of paroxysmal nocturnal hemoglobinuria, C3 glomerulopathy and immune complex membranoproliferative glomerulonephritis, and hematopoietic stem cell transplantation-associated thrombotic microangiopathy; and SYFOVRE for treating geographic atrophy secondary to age-related macular degeneration and geographic atrophy (GA). The company also develops APL-3007, a small interfering RNA, or siRNA, which is in a Phase 1 clinical trial, as well as an oral complement inhibitor that is in preclinical development. It has a collaboration and license agreement with Swedish Orphan Biovitrum AB (publ) for development and commercialization of pegcetacoplan; and a collaboration with Beam Therapeutics Inc. focused on the use of Beam's base editing technology to discover new treatments for complement-driven diseases. The company was incorporated in 2009 and is based in Waltham, Massachusetts.

Kymera Therapeutics, Inc., a biopharmaceutical company, focuses on discovering and developing novel small molecule therapeutics that selectively degrade disease-causing proteins by harnessing the body's own natural protein degradation system. It engages in developing IRAK4 program, which is in Phase II clinical trial for the treatment of immunology-inflammation diseases, including hidradenitis suppurativa, atopic dermatitis; STAT3 program for the treatment of hematologic malignancies and solid tumors, as well as autoimmune diseases and fibrosis; and MDM2 program to treat hematological malignancies and solid tumors. The company develops STAT6, a Type 2 inflammation in allergic diseases; and TYK2, a treatment for inflammatory bowel disease, psoriasis, psoriatic arthritis, and lupus. The company was incorporated in 2015 and is headquartered in Watertown, Massachusetts.

KalVista Pharmaceuticals, Inc., a clinical stage pharmaceutical company, engages in the discovery, development, and commercialization of drug therapies inhibitors for diseases with unmet needs. The company's product candidate is Sebetralstat, a small molecule plasma kallikrein inhibitor targeting the disease of hereditary angioedema (HAE). It develops Factor XIIa, an oral inhibitor for the treatment of HAE which is in preclinical trial. In addition, the company is developing an orally disintegrating tablet formulation, including KONFIDENT-KID for pediatric use with HAE; KONFIDENT-S for adolescent and adult patients with type I or type II HAE; and KONFIDENT for a potential oral therapy for HAE attacks. The company is headquartered in Cambridge, Massachusetts.

Astria Therapeutics, Inc., a biopharmaceutical company, focuses on the discovery, development, and commercialization of therapeutics for allergic and immunological diseases in the United States. Its lead product candidate is STAR-0215, a monoclonal antibody inhibitor of plasma kallikrein, which is in Phase 1b/2 clinical trials for the treatment of hereditary angioedema. The company is also developing STAR-0310, a monoclonal antibody OX40 antagonist that is in preclinical development for the treatment of atopic dermatitis, an immune disorder associated with loss of skin barrier function and itching. The company was formerly known as Catabasis Pharmaceuticals, Inc. and changed its name to Astria Therapeutics, Inc. in September 2021. Astria Therapeutics, Inc. was incorporated in 2008 and is headquartered in Boston, Massachusetts.

Compass Therapeutics, Inc., a clinical-stage oncology-focused biopharmaceutical company, engages in developing antibody-based therapeutics to treat various human diseases in the United States. The company's lead product candidates include CTX-009, a bispecific antibody that blocks Delta-like ligand 4 a ligand of Notch-1, and vascular endothelial growth factor A signaling pathways, which are critical to angiogenesis and tumor vascularization; and CTX-471, an IgG4 monoclonal antibody that is an agonist of CD137, a key co-stimulatory receptor on immune cells. It also develops CTX-8371, a bispecific inhibitor that targets PD-1 and PD-L1 checkpoint inhibitor antibodies. The company was founded in 2014 and is headquartered in Boston, Massachusetts.

Acelyrin, Inc., a clinical biopharma company, focuses on identifying, acquiring, and accelerating the development and commercialization of transformative medicines. The company's lead product candidate is izokibep, a small protein therapeutic designed to inhibit IL-17A with high potency, which is in Phase 3 clinical trials for use in the treatment of Hidradenitis Suppurativa, Psoriatic Arthritis, and uveitis, as well as in Phase 2 clinical trials for use in the treatment of Axial Spondyloarthritis. It is also developing lonigutamab, a humanized immunoglobulin G1 (IgG1) monoclonal antibody which is in Phase 1 clinical trials for use in the treatment of thyroid eye disease. In addition, the company's develops SLRN-517, a fully human IgG1 monoclonal antibody targeting c-KIT, which is in preclinical stage for use in the treatment of chronic urticaria. Acelyrin, Inc. was incorporated in 2020 and is headquartered in Agoura Hills, California.

Aclaris Therapeutics, Inc. a clinical-stage biopharmaceutical company, engages in the development of novel drug candidates for immune-inflammatory diseases in the United States. The company operates through two segments, Therapeutics and Contract Research. The Therapeutics segment is involved in identifying and developing therapies to address significant unmet needs for immuno-inflammatory diseases. The Contract Research segment provides laboratory services. It develops Zunsemetinib (ATI-450), an MK2 inhibitor which is under Phase 1b/2 trials for the treatment of metastatic breast and pancreatic cancer; ATI-1777, a soft JAK 1/3 inhibitor, completed Phase 2b trails for the treatment of moderate to severe atopic dermatitis and other dermatologic conditions; and ATI-2138, an oral covalent inhibitor of ITK and JAK3 inhibitor under Phase 1 trials as a treatment for T cell-mediated autoimmune diseases. The company was incorporated in 2012 and is headquartered in Wayne, Pennsylvania.

Q32 Bio Inc., a clinical-stage biotechnology company, develops biologic therapeutics to restore healthy immune balance in patients with autoimmune and inflammatory diseases driven by pathological immune dysfunction in the United States. Its lead product candidate is ADX-097, a humanized anti-C3d monoclonal antibody fusion protein to restore complement regulation, which has completed Phase I clinical trial for the treatment of renal and other complement-mediated diseases of high unmet need, including lupus nephritis, immunoglobulin A nephropathy, complement component 3 glomerulopathy, and anti-neutrophil cytoplasmic antibody-associated vasculitis. The company is also developing Bempikibart (ADX-914), a fully human anti–interleukin-7 receptor alpha antagonist monoclonal antibody designed to re-regulate adaptive immune function by blocking signaling mediated by interleukin-7 and thymic stromal lymphopoietin that is Phase II clinical trial for the treatment of atopic dermatitis and alopecia areata. Q32 Bio Inc. was formerly known as AdMIRx Inc. and changed its name to Q32 Bio Inc. in April 2020. The company was founded in 2017 and is based in Waltham, Massachusetts.