In the spring, Asher Biotherapeutics emerged from stealth with a new technology, a leading cancer immunotherapy drug candidate, and cash in the clinic. Clinical trials are coming, but the startup now has additional preclinical data showing that its drug is better than rival immunotherapy candidates, and the results of these animal trials have persuaded investors to inject an additional US$108 million into the company .
Wellington Management Company led the round of financing announced on Wednesday.
Asher Bio’s research focus in South San Francisco is interleukin 2 (IL-2), a signaling protein that stimulates an immune response in the body. Engineered IL-2 therapies have been available for many years, but their wide range of effects beyond expected target cells and their toxicity limit their use. Asher aims to overcome these problems by activating the IL-2 pathway in a more targeted way.
Asher’s drugs can achieve targeting because they are designed to hit two receptors on the same target cell. The company calls its approach cis-targeting. Lead Asher Bio’s drug candidate AB248 is a fusion protein designed to selectively activate the IL-2 pathway on specific types of immune cells (called CD8+ T cells).when Asher Bio completed a US$55 million Series A financing in March, The company’s mouse data showed that immunotherapy cleared the tumor.
CEO Craig Gibbs said in an e-mail that in the following months, Asher Bio generated more data and stimulated investor interest. The company now compares AB248 with another IL-2 drug and shows that a single dose of Asher fusion protein is better at eliminating most of the tumors in three different mouse tumor models. These effects were achieved without weight loss in the mice, which would be a sign of adverse reactions. He added that preliminary toxicological data from the monkey study indicated that the therapy has a good therapeutic index.
Gibbs did not determine the immunotherapy compared to Asher’s drug, only that it is a “leading clinical-stage IL-2 therapy candidate.”This description is in line with THOR-707, Synthorx’s main IL-2 therapy and the core of the biotechnology’s $2.5 billion Acquired by Sanofi last year.At the American Association for Cancer Research Annual Meeting in April, Sanofi reported that Preliminary data for the first stage It shows that THOR-707 itself has anti-tumor activity and is used in combination with an immunotherapy called a checkpoint inhibitor. Xilio Therapetics is also developing an IL-2 drug, but the biotech company based in Waltham, Massachusetts has not yet entered the clinic.
So far, Asher has not published any research. Gibbs said the company plans to present the data at a medical conference this fall, and then publish the data in peer-reviewed journals. Asher has more IL-2 drugs in development. Gibbs said the company has already demonstrated preclinical proof-of-concept for two other projects. The new Series B financing will support the company’s leading projects through the second phase of development; it is expected that there will be an investigational new drug application in the third quarter of next year. The cash will also enable the company to advance the second project through preclinical research leading to clinical testing.
Other new Asher Bio investors joining the latest funding include RA Capital Management, Janus Henderson Investors, Logos Capital, Marshall Wace and Alexandria Venture Investments. Early investors Third Rock Ventures, Invus, Tavistock Group’s Boxer Capital, and Mission BioCapital also participated in the financing. Some Series B investors are companies that invest funds in private companies and public companies. Obtaining large amounts of cash from such “cross-border” investors can be seen as a sign that the company is preparing for an IPO.
Gibbs will not say whether this round is a crossover. He stated that Asher’s goal is to have a group of leading life science investors, including investors experienced in the private and public markets, to support the company’s leading plans and enable the company to fully utilize the potential of the cis-targeting platform.
“We believe that this puts Asher Bio in the best position to have strong and diversified investors, so we have a wealth of expertise and capital to seek a series of opportunities for our future growth,” Gibbs said.
