New Haven, Connecticut, USA, November 5, 2026
Biohaven Ltd. has announced continued progress in its research programme for Graves’ disease, including active enrolment in a pivotal Phase 3 clinical trial of BHV-1300 and three scientific poster presentations at the 2026 American Thyroid Association (ATA) Annual Meeting in Philadelphia. The announcement highlights the company’s effort to develop a treatment approach that targets the autoimmune mechanism responsible for Graves’ disease rather than focusing only on controlling excess thyroid hormone. The Phase 3 study, registered as NCT07661056, is a randomized, double-blind, placebo-controlled trial expected to enrol approximately 300 adults. It is evaluating whether BHV-1300 can help restore normal thyroid function at Week 26 without the use of antithyroid medication. According to Biohaven, the trial is enrolling at more than 55 active sites across the United States and Canada, with additional sites planned in Japan, the United Kingdom, Australia and the European Union. The programme represents an important clinical development milestone for the company’s extracellular protein degradation technology. Graves’ disease is an autoimmune condition and a leading cause of hyperthyroidism. It occurs when antibodies target and stimulate the thyroid-stimulating hormone receptor (TSHR), prompting the thyroid gland to produce excessive thyroid hormones. Existing treatment options include antithyroid medicines, radioactive iodine and thyroidectomy. These approaches manage thyroid hormone production or remove thyroid tissue, but they do not directly eliminate the disease-driving autoantibodies. Biohaven is investigating whether BHV-1300 can address this underlying autoimmune process by selectively reducing pathogenic antibodies.
BHV-1300 Shows Autoantibody Reduction in Phase 1b
BHV-1300 is an investigational small-molecule therapy developed using Biohaven’s MoDE™ extracellular protein degrader platform, a technology exclusively licensed from Yale University. The molecule is designed to bind selected immunoglobulin G (IgG) antibodies and direct them to the liver’s natural protein-clearance system. It engages the asialoglycoprotein receptor (ASGPR) on liver cells, enabling the targeted antibodies to be taken into cells and degraded through lysosomal pathways. The approach is intended to remove disease-associated proteins from circulation rather than simply blocking their activity or suppressing their production. In a Phase 1b study, weekly subcutaneous administration of BHV-1300 at 1,000 mg produced an approximately 80% reduction in pathogenic anti-TSHR-IgG1 autoantibodies by Week 12. Among patients who remained hyperthyroid despite antithyroid drug treatment, free T4 levels normalized at a median of three weeks, while free T3 levels normalized at a median of five weeks. Biohaven also reported that the treatment spared IgG3, an antibody subclass that contributes to protection against bacterial, viral and parasitic infections. These findings provide early clinical evidence supporting further investigation of the drug candidate. However, Phase 1b results do not establish its effectiveness or safety in a larger population; the ongoing Phase 3 study will assess its clinical performance under controlled conditions.
ATA Presentations Highlight Patient Needs and New Research
Alongside the clinical trial update, Biohaven presented three scientific posters at the 2026 ATA Annual Meeting, held from November 4 to 7 in Philadelphia. One presentation examined the patient experience and the wider burden of Graves’ disease through interviews with 14 adults. The findings showed that symptoms often occurred together: 93% of participants reported at least two symptoms, while 71% reported five or more. Fatigue was reported by 93%, and all participants described an emotional impact, including anxiety, depression or changes in self-image. Notably, participants who reported well-controlled thyroid hormone levels also described persistent or recurring symptoms. The findings underline the importance of assessing patients’ quality of life alongside laboratory measurements. A second poster evaluated how well the ThyPRO-39 short-form questionnaire captures symptoms and impacts experienced by people with Graves’ disease. The interview findings mapped to 31 of the questionnaire’s 38 items, supporting its potential relevance for assessing patient-reported outcomes in this population.
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The third poster presented preclinical research on BHV-1440, an investigational TRAP™ degrader designed to selectively target anti-TSHR autoantibodies. In laboratory studies, the candidate directed the antibodies towards liver-cell degradation. In a mouse model, a single subcutaneous dose reduced circulating antibody levels and returned elevated T4 levels to baseline within 24 hours. These findings remain preclinical and do not demonstrate clinical benefit in humans. Biohaven also reported an October 2026 licensing agreement with Ono Pharmaceutical covering its MoDE pan-IgG degrader portfolio in Japan, South Korea, Taiwan and ASEAN markets. Overall, the Phase 3 programme and ATA research presentations demonstrate Biohaven’s expanding strategy to investigate therapies that target the biological drivers of autoimmune disease. BHV-1300 remains investigational, and its potential role in treating Graves’ disease will depend on the results of the ongoing pivotal trial.
Source: Biohaven press release
