BeyondSpring (NASDAQ: BYSI) will present a promising new strategy for cancer treatment involving the ability of its lead asset, Plinabulin, to positively shift the balance of macrophage phenotypes for a beneficial anti-cancer effect at the 2019 American Association for Cancer Research annual meeting in Atlanta on April 3.
Tumor-associated macrophages are believed to play an important role in the growth, progression and metastasis of tumors. While macrophages with an M1 phenotype have anti-cancer functions, M2 macrophages are thought to support tumor cell survival and metastasis. Having the ability to increase M1 and/or reduce M2 macrophages may help the immune system to slow the growth of tumors or reject tumors.
Collaborators of BeyondSpring at the University of Basel demonstrated that Plinabulin not only reduced tumor-associated M2 macrophages in a murine cancer model, but also shifted the phenotypic balance to one favoring M1 macrophages. In addition, Plinabulin treatment shifted the M1/M2 balance towards M1 for human donor cells in vitro.
“Shifting the M1/M2 ratio to a predominant M1 phenotype can shift the balance from an immune-suppressive to an immune-enhancing tumor microenvironment,” Dr. Ramon Mohanlal, EVP of R&D and CMO of BeyondSpring, said in a statement.
“The finding of Plinabulin’s ability to improve the M1/M2 balance, along with the prior demonstration of increased dendritic cell maturation with Plinabulin treatment, support the potential utility of adding Plinabulin to established checkpoint-inhibitor therapy to increase potency, and to potentially reverse resistance to these checkpoint inhibitors. Early stage clinical trials are underway to test these new strategies,” he added.
