Third Harmonic Bio raises $105M in series B to push hives treatment through phase 1b

Third Harmonic Bio raised more than $105 million from its series B round, money the company says will be used to further develop its treatment for chronic hives through a phase 1b trial slated for later this year. 

Combined with an earlier series A round, the Cambridge, Massachusetts-biotech has raised more than $150 million to date. 

Third Harmonic’s first and only candidate, THB001, is an oral KIT inhibitor meant to treat severe allergies and inflammation. KIT is a cell surface receptor responsible for regulating the function of mast cells, which exist in parts of the body that interact with the outside environment. When activated, they can trigger allergic reactions. By blocking KIT’s function, the company hopes its drug can stymie mast-cell-driven inflammation. 

The drug is currently in phase 1 trials following pre-clinical studies that showed it was associated with a depletion of mast cell activity in relevant tissue types. A phase 1b proof-of-concept trial focused on cold temperature-induced hives is slated for the second half of the company's 2022 fiscal year. Looking further, the company plans to test the drug for other diseases triggered by mast cells.  

RELATED: Novartis suffers shock setback as Xolair successor fails phase 3

The company hopes to break into a market currently dominated by Novartis’ Xolair, which is FDA-approved to treat chronic spontaneous hives in addition to asthma. In 2021, the drug raked in more than $1.4 billion in revenue. 

Third Harmonic Bio's latest round was led by a new investor, General Atlantic, along with founders Atlas Venture and existing investors BVF Partners and OrbiMed.