Alpha-1 Biologics Announces Positive Data Published in frontiers in Oncology on Alphataxin in Combination with Anti-PD-1 Therapy that Suppressed Murine Renal Cancer and Metastasis

Alpha-1 Biologics, a biotherapeutics company developing innovative treatments for cancers and immune deficiencies, today announced that positive data was published in frontiers in Oncology demonstrating Alphataxin, a small molecule that elevates circulating and tumor-infiltrating CD4+ T cells, suppressed kidney cancer and suppressed metastasis in mice. Orally available Alphataxin, is the first and only drug in development to increase formation of CD4+ helper T cells. Immune checkpoint inhibitor therapy, the vanguard of cancer therapy, promotes the ability of CD8+ T cells to kill tumor cells. However, CD8+ T cells are unable to kill tumor cells in the absence of chemical mediators secreted by CD4+ helper T cells. The data showed that Alphataxin treatment is efficacious as a monotherapy in kidney cancer in mice and enhances anti-PD-1 immune checkpoint inhibitor therapy, with the potential to expand the number of human cancer patients who respond to checkpoint inhibitor therapy

Cynthia L. Bristow, PhD, CEO of Alpha-1 Biologics said, “We are excited to announce this positive pre-clinical data, which showed that Alphataxin, orally delivered in combination with an injected immune checkpoint inhibitor, may provide a powerful approach that can produce long-term remission in kidney cancer and other T cell-responsive tumors. Alphataxin as a monotherapy and in combination with anti-PD-1 immune checkpoint inhibitor therapy significantly suppressed tumor growth in a mouse model of kidney cancer and significantly elevated the number of circulating and tumor-infiltrating CD4+ T cells.”

The research and development of Alphataxin has been supported by the non-profit research organization, Institute for Human Genetics and Biochemistry (IHGB), funded by the Harry Winston Research Foundation. Ron Winston, President, Institute for Human Genetics and Biochemistry said, “We are pleased with these pre-clinical results, which have further increased our confidence in the promising potential of Alphataxin to treat cancers and immune deficiencies. Based on this positive data, the company plans to raise additional capital to rapidly advance the Alphataxin development program.”

In the study, following implantation of mouse kidney tumor cells within the kidney of mice, combination treatment of Alphataxin and anti-PD-1 therapy resulted in 100% elimination of tumor growth. Moreover, in mice implanted with ten times more tumor cells into the kidney, doubling the Alphataxin dose in combination treatment with anti-PD-1 led to 100% elimination of tumors in one-third of mice and 81% suppression of tumor growth in the remaining twothirds of mice. Both anti-PD-1 and Alphataxin monotherapy showed decreased tumor growth as compared with untreated mice. Lung metastasis was present in monotherapy but eliminated in combination-treated mice.

The study also investigated the effects of Alphataxin on the immune system in healthy mice. The data showed that Alphataxin increased the normally circulating numbers of CD4+ T cells, Pre-T cells, and CD4/CD8 ratio indicating that Alphataxin acts to increase the formation of CD4+ helper T cells.

“This combination treatment of Alphataxin with an anti-PD-1 therapy addresses a high unmet medical need in patients with kidney cancer who have very low survival rates. The 5-year survival rate for patients with renal adenocarcinoma undergoing anti-PD-1 treatment is estimated to be 27.7%. However, despite the efficacy of checkpoint inhibitors in promoting the cytotoxic activities of tumor infiltrating CD8+ T cells, approximately 87% of cancer patients do not respond to immune checkpoint therapy,” said Dr. Bristow. “Kidney cancer is often not diagnosed until after metastasis, a disease stage for which there are few effective treatment options; however, recent promising advances demonstrate that easily accessible blood-based tests provide early detection, and this means that Alphataxin has the potential to be transformative in providing long lasting remission in kidney cancer.”