Third Harmonic Bio stockholders have overwhelmingly approved the company's plan to liquidate and dissolve operations, marking the end of the biotech's journey that began with a $185 million IPO in 2022. The vote, held at the company's June 5, 2025 annual meeting, saw 99.9% of voting shares and 83.7% of total outstanding shares support the dissolution plan.
The San Francisco-based company expects to make an initial distribution of approximately $5.30 to $5.35 per share to stockholders in the third quarter of 2025, subject to final board approval. Total distributions are estimated to range between $5.30 and $5.44 per share, with additional proceeds potentially available from asset sales.
THB335 Demonstrates Strong Biomarker Response
Despite the company's dissolution plans, Third Harmonic announced encouraging new clinical data for its lead asset THB335, an oral wild-type KIT inhibitor. In a recently completed Phase 1 cohort of 10 healthy volunteers, the drug candidate achieved an 85% mean reduction from baseline in serum tryptase, a biomarker of mast cell activation, when administered at 100mg once daily for 14 days.
The 100mg dose demonstrated pharmacokinetics and pharmacodynamics largely consistent with the previously tested 164mg dose level, with mean plasma trough exposures exceeding the 90% inhibition concentration (IC90) of KIT by over six-fold. The new formulation utilized an improved drug product capsule intended for future clinical development.
Safety data from the cohort showed all adverse events were mild except for one moderate case of neutrophil reduction. Notably, there were no adverse events related to hemoglobin reduction or other clinically significant laboratory changes. One subject experienced mild hair color change and taste loss, both of which resolved during follow-up.
Phase 2 Readiness and Asset Sale Process
Third Harmonic has completed all clinical, toxicology, and manufacturing activities necessary to support a Phase 2 clinical trial of THB335 for chronic spontaneous urticaria treatment. The company plans to submit a regulatory filing with the FDA imminently to seek clearance for trial initiation.
As part of the dissolution plan, Third Harmonic is initiating a sale process for THB335 and related intellectual property. The company has directed interested parties to contact Chief Financial and Business Officer Chris Murphy for more information about the asset sale.
Industry Trend Toward Strategic Dissolution
Third Harmonic's decision reflects a broader industry trend where biotechnology companies are choosing dissolution over continued operations following clinical setbacks. The company initially halted its clinical study months after its 2022 IPO due to liver toxicities observed in trial participants.
Founded by Atlas Venture in 2019, Third Harmonic had originally focused on developing an oral mast cell inhibitor for chronic inducible urticaria. In February 2025, the company announced plans to evaluate strategic alternatives while reporting Phase 1 results for THB335 in healthy volunteers. It subsequently laid off half its staff and ceased all R&D work outside of the THB335 program.
As of December 31, 2024, Third Harmonic held $285 million in cash and cash equivalents. The company expects to distribute between $246.6 million and $255.4 million to shareholders if the dissolution plan proceeds as planned.
The biotech joins other companies including Acelyrin, Cargo Therapeutics, and BioAge Labs that have experienced dramatic stock price declines after clinical disappointments. Industry analysts have noted that investors are increasingly scrutinizing these "zombie" companies and arguing that their accumulated cash could be better deployed elsewhere rather than funding programs that lack investor support.
