Our Pipeline

We are relentless in pursuing breakthroughs that boldly change the lives of the communities we serve.

Our pipeline is built on purpose, and our scientific courage drives us to tackle many marginalized, overlooked or forgotten diseases.


Rare Diseases




HZN-001 (teprotumumab)

  • OPTIC trial: Phase 3 complete
  • OPTIC-X trial: Phase 3 extension


HZN-001 (teprotumumab) is a fully human monoclonal antibody, insulin-like growth factor-1 receptor (IGF-1R) inhibitor being evaluated for the treatment of active thyroid eye disease (TED). Teprotumumab has received Breakthrough Therapy, Orphan Drug and Fast Track designations from the U.S. Food and Drug Administration.

TED is a progressive, debilitating autoimmune disease with a limited window for pharmacologic treatment during the active disease. In patients with active TED, IGF-1R is overexpressed on orbital fibroblasts, resulting in inflammation and tissue expansion behind the eye, causing serious damage – including proptosis (eye bulging), strabismus (misalignment of the eyes), and diplopia (double vision) – and in some cases can lead to blindness. 1,2

For more information about TED, please visit our disease information page. For more information on teprotumumab, please visit clinicaltrials.gov.

Teprotumumab is an investigational medicine and its safety and efficacy have not been established.


  1. The 2016 European Thyroid Association/European Group on Graves' Orbitopathy Guidelines for the Management of Graves' Orbitopathy. European Thyroid Journal.2 March 2016. https://www.ncbi.nlm.nih.gov/pubmed/27099835. Accessed Feb 22, 2019.
  2. Update on thyroid eye disease and management. Clinical Ophthalmology. 19 October 2009. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2770865/. Accessed Feb 22, 2019.

Rheumatic Diseases





  • Optimized uricase and optimized PEGylation for uncontrolled gout


HZN-003 is a genetically engineered uricase derivative, next generation gout biologic with optimized uricase and optimized PEGylation technology.


PASylated Uricase

  • Optimized uricase and PASylation for uncontrolled gout


Collaboration agreement with XL-protein GmbH to identify clinical-stage product candidates that could be used to construct a next-generation gout biologic. If the collaboration agreement identifies clinical stage candidates, Horizon will have the right to license the candidates.


KRYSTEXXA® (pegloticase)

  • MIRROR immunomodulation study: KRYSTEXXA + methotrexate

PHASE 3b / 4

Methotrexate to Increase Response Rates in Patients with Uncontrolled GOut Receiving KRYSTEXXA (MIRROR): Horizon sponsored multicenter, efficacy and safety study for methotrexate co-administered with KRYSTEXXA to evaluate the impact of methotrexate weekly for one month prior to dosing with KRYSTEXXA and then throughout the 24 weeks of treatment with KRYSTEXXA.

For more information about gout, please visit our disease information page. For more information on KRYSTEXXA, please see KRYSTEXXA.com.

Recent Clinical Milestones



RAVICTI® (glycerol phenylbutyrate) Oral Liquid

  • Label expansion: birth to 2 months

Discovery Collaborations




Gout Discovery Collaboration

  • Exploration of novel approaches to treating gout


Collaboration with HemoShear Therapeutics, LLC, to explore novel approaches to identify and validate biological targets to treat gout using HemoShear’s proprietary disease modeling platform, REVEAL-Tx™. The platform combines physiological and computational models of disease to identify novel treatment approaches. This collaboration may lead to potential clinical targets or new studies of which Horizon will have the rights to commercialize any successful candidates.

Clinical Trials

Clinical trials are an important part of the research and development process. People who participate in clinical trials play a vital role in helping physicians and investigators understand how an investigational medicine may be able to safely and effectively treat a specific disease or condition.

For a comprehensive list of current clinical trials involving Horizon medicines, please visit www.clinicaltrials.gov.


This information was last updated on May 7, 2019.