Tourmaline heads to Nasdaq, inking Talaris reverse merger to fund midphase trials of Pfizer castoff

Talaris Therapeutics’ plans have crystallized. Having stopped its transplant programs and hunkered down, the biotech has now entered into a reverse merger that will provide Tourmaline Bio with a platform for taking an ex-Pfizer drug into midphase clinical trials. 

Tourmaline has kept a low profile up to this point. Founded and helmed by Sandeep Kulkarni, M.D., formerly of Roivant Sciences, the biotech licensed an anti-IL-6 antibody from Pfizer in May 2022. The Big Pharma had tested the candidate in phase 1 and 2 studies before deeming it surplus to requirements, allowing Tourmaline to swoop in and plot a two-front clinical trial program for the asset, now known as TOUR006.

The New York-based biotech aims to start a phase 2b trial in thyroid eye disease (TED), an autoimmune disorder also known as Graves’ ophthalmopathy, in the third quarter of this year. A phase 2 study of the drug candidate in atherosclerotic cardiovascular disease (ASCVD) is scheduled to start next year.

Tourmaline is pursuing different indications than Pfizer is. The Big Pharma ran phase 1 and 2 trials of the same antibody in Crohn's disease, lupus and rheumatoid arthritis from 2010 to 2016. Pfizer’s focus overlapped with the priorities of other developers of IL-6 drugs such as Sanofi-Regeneron and Roche, which respectively sell Kevzara and Actemra in indications including rheumatoid arthritis. 

TOUR006 is on a different path. Tourmaline sees opportunities to develop the drug in “diseases characterized by inflammation and autoantibodies, where IL-6 pathway inhibitors have been underexplored despite compelling signals of clinical benefit.” That focus led the biotech to TED, a disease in which IL-6 drugs have been used off-label, and ASCVD, owing to clinical and genetic data on IL-6.

To fund the work, Tourmaline has arranged the reverse merger with Talaris, which will give it a listing on Nasdaq, and agreed to a $75 million private placement. The placement is supported by the investors that co-led the biotech’s $112 million series A round—Deep Track Capital, Cowen Healthcare Investments and TCGX—and involves new backers including RA Capital Management.

The biotech expects to emerge from the merger with $210 million. Talaris will pay its shareholders a cash dividend of around $65 million, and they will also own more than one-fifth of the combined company.

Striking the deal marks the end of Talaris’ search for a way out of its predicament. Things started to go wrong for the biotech when the death of a patient caused it to pause its phase 3 kidney transplant trial. The biotech restarted its trials late last year only to stop work in February, lay off one-third of its staff and look for a buyer. When a fast deal failed to materialize, Talaris laid off almost all its remaining staff. 

News of the deal broke on a busy day for biotech M&A that also saw Solve Therapeutics disclose the acquisition of Duke University spinout Cereius, a developer of targeted radiodiagnostics and radiotherapeutics for cancer patients.