BioPharma, Startups

ALX Oncology raises $105M in Series C round for checkpoint inhibitor development

The company is working to move its CD47-targeting drug, ALX148, into Phase II development. Another company, Forty Seven, is also developing a CD47-targeting therapy. CD47 is an immune checkpoint distinct from the ones targeted by currently marketed cancer immunotherapy drugs.

A company developing a drug that targets a protein overexpressed on the surface of cancer cells and enables them to evade the immune system has raised more than $100 million in its latest funding round.

Burlingame, California-based ALX Oncology said Wednesday that it had raised $105 million in a Series C equity financing. Vivo Capital led the round, while Logos Capital, Janus Henderson, Foresite Capital, Cormorant Asset Management, BVF Partners and HBM Healthcare Investments are among the company’s new investors. Existing investors venBio and Lightstone Ventures also participated.

The company plans to invest the money in its lead drug candidate, ALX148, a CD47-targeting checkpoint inhibitor that it is developing in combination with other therapies in solid tumors and blood cancers. The drug is designed to maximize the clinical benefit of other monoclonal antibodies.

The drug is currently in a Phase I clinical trial of 184 participants. In the first part of the study, patients receive the drug as a single agent at escalating dose levels; in the second part, they will receive it in combination with other cancer therapies, including Merck’s PD-1 checkpoint inhibitor Keytruda (pembrolizumab) and others. It is enrolling patients with solid tumors and also with non-Hodgkin’s lymphoma, and the company is planning to further move ALX148 into Phase II clinical development.

“We see tremendous opportunity for ALX148 to help cure a wide range of cancer types and become a major new checkpoint inhibitor to combine with a variety of anti-cancer antibodies, checkpoint inhibitors and other anti-cancer agents,” Vivo Capital Managing Director Jack Nielsen said in a statement.

Another company developing a CD47-targeting drug is Menlo Park, California-based Forty Seven, whose lead candidate, magrolimab, is in Phase I and Phase II development for acute myeloid leukemia, myelodysplastic syndrome, non-Hodgkin’s lymphoma and solid tumors like colorectal, ovarian and bladder cancers. Its clinical trials also involve combination with antibody-based therapies.

The checkpoint inhibitors currently on the market – those targeting PD-1 or PD-L1 like Keytruda and Roche’s Tecentriq (atezolizumab) or CTLA-4 like Bristol-Myers Squibb’s Yervoy (ipilimumab) – work by stimulating the body’s adaptive immune system. The strategy of blocking CD47/SIRPa signaling axis works by stimulating the innate immune system’s myeloid cells. CD47 sends what is sometimes called the “don’t eat me” signal and is expressed on normal cells, but overexpressed on cancer cells. Thus, an anti-CD47 antibody works by targeting that protein and allowing myeloid cells to detect and kill cancerous cells via their corresponding receptor, SIRPa. Studies have also indicated that targeting the CD47/SIRPa axis can stimulate the adaptive immune system.

Photo: Feodora Chiosea, Getty Images