Venture investors have long been keen backers of startups working on treatments for asthma and other respiratory ailments. Lately, it looks like activity is scaling up further.

On Tuesday, San Francisco- and London-based Aiolos Bio, a newly launched startup with an asthma drug in clinical trials, announced that it raised $245 million in Series A funding. Atlas Venture, Bain Capital Life Sciences, Forbion Capital Partners and Sofinnova Investments led the round, with additional investment from RA Capital Management.

Aiolos plans to use the funds for phase 2 clinical trials of its lead drug candidate, AIO-001, for moderate-to-severe asthma patients. It will also pursue potential applications of the monoclonal antibody therapeutic for other conditions, including chronic obstructive pulmonary disorder, after securing global rights to develop and commercialize the drug outside China from Jiangsu Hengrui Pharmaceuticals.

A multibillion-dollar cohort

With its Series A, Aiolos joins a heavily funded cohort of private, venture-backed companies focused on asthma and respiratory disease. Using Crunchbase data, we put together a list of 22 startups funded in the past several quarters that have collectively raised close to $1.8 billion.

The most heavily funded company on the list is Waltham, Massachusetts-based Upstream Bio, which has secured over $400 million in venture funding to date. On Tuesday, the company announced that it has collected positive interim data for the latest clinical trial of its asthma therapeutic.

Next is asthma-focused Areteia Therapeutics, which launched in mid-2022 with $350 million in Series A funding led by Bain Capital Life Sciences. Maverick Capital, Sanofi and Access Biotechnology. The company, which was spun off from Pennsylvania-based Knopp Biosciences, is focused on an oral drug for eosinophilic asthma. Around half of the world’s asthma patients have eosinophilic asthma, which limits airflow in the lungs.

Growing demand for therapies

While investments in asthma and respiratory therapy startups is significant, it looks rather small in comparison to the amount of money that goes into treating existing cases.

The Asthma and Allergy Foundation of America estimates asthma costs the health care system over $50 billion a year in the U.S. alone for clinician labor and hospital resources. Globally, per the WTO, asthma and respiratory ailments tied to air pollution, remain a growing threat.

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Illustration: Dom Guzman