Attune Pharmaceuticals bags $23M for oral HAE drug

Attune is working on an oral drug for hereditary angioedema, all of the treatments for which are either subcutaneous or intravenous injections. (Nadine Doerlé)

Attune Pharmaceuticals raised $23 million in series B financing to push its oral drug for hereditary angioedema (HAE) through phase 2. The biotech aims to provide an oral alternative to approved treatments, all of which are either intravenous or subcutaneous injections. 

The financing (PDF) comes one day after Attune presented phase 1 data (PDF) for ATN-249 at the annual scientific session of the Western Society of Allergy, Asthma and Immunology. In addition to advancing the HAE candidate, ATN-249, the funding will also support the development of Attune’s preclinical pipeline. 

HAE is a rare disease caused by the deficiency of a plasma protein called C1-esterase inhibitor. It causes rapid swelling of the hands, feet, limbs, face, intestinal tract or airway that can be life-threatening. Several drugs have been approved to treat HAE, including CSL’s Haegarda and Shire’s Cinryze, both of which boost C1-esterase inhibitor activity. Attune’s ATN-249 inhibits a different target to reduce HAE attacks: the enzyme kallikrein. 

This isn’t a new target in HAE, said Attune CEO Andrew McDonald, Ph.D. Shire’s Takhzyro, which was approved in August, inhibits the same enzyme. 

“Plasma kallikrein is a validated target … Now that we’ve finished phase 1, it’s about finding the right dose to test efficacy in a phase 2 study,” McDonald said. 

While the benefits of an oral drug over an injectable one are obvious, creating an oral formulation has been challenging. Attune made more than 1,200 different compounds before it struck the balance of oral bioavailability and therapeutic properties. North Carolina-based BioCryst Pharma is also working on an oral plasma kallikrein inhibitor. It announced positive midstage data in September. 

Venrock Healthcare Partners led the series B, with LifeSci Venture Partners, RTW Investments, RA Capital, Boxer Capital and Tang Capital also participating.  

“This financing brings together a syndicate of investors with a deep understanding and long history of supporting companies that develop novel HAE therapeutics,” McDonald said in a statement. 

Attune’s team has experience working on HAE drugs, too; Chief Medical Officer Ira Kalfus, M.D., and Chief Operating Officer Jason Bablak developed Cinryze “in their previous lives,” McDonald said. The team is currently at four, but Attune plans to hire a project manager for the phase 2 trial and to put some more folks on its board of directors, McDonald said.