Third Harmonic Bio to Liquidate, Selling Key Urticaria Drug Asset THB335

Third Harmonic Bio, a clinical-stage biotech company, is liquidating and selling its primary drug candidate, THB335, a KIT inhibitor intended for chronic spontaneous urticaria (CSU)26.
The decision follows a financial and strategic review that began after the company cut its workforce by 50% earlier in 2025 to focus solely on THB335 development23.
The drug demonstrated dose-dependent reductions in serum tryptase, a biomarker of mast cell activation, in Phase 1 trials, though side effects such as hair loss and hemoglobin reduction were noted34.
As of April 2025, Third Harmonic had approximately $272 million in cash reserves. Post-liquidation, between $246.6 million to $259.8 million is expected to be returned to shareholders, equating to $5.13 to $5.42 per share26.
The Phase 2 readiness activities for THB335 will be completed by mid-2025 to attract potential buyers, and a shareholder vote on the dissolution is scheduled for June 5, 2025210.
The company plans to delist from Nasdaq and officially dissolve, citing better value creation for shareholders through liquidation rather than further R&D pursuits210.

Sources:

2. https://www.fiercebiotech.com/biotech/third-harmonics-song-end-biotech-looks-liquidate-sell-urticaria-drug

3. https://www.fiercebiotech.com/biotech/third-harmonic-halves-headcount-take-urticaria-drug-phase-2-despite-side-effects

4. https://www.biospace.com/press-releases/third-harmonic-bio-announces-phase-1-clinical-results-for-thb335-and-provides-corporate-strategic-update

6. https://seekingalpha.com/news/4430863-third-harmonic-bio-plans-to-liquidate-the-company-sell-urticaria-treatment

10. https://www.biopharmadive.com/news/third-harmonic-bio-dissolution-strategic-alternatives/745263/