Data presented at the AACR Conference on Pancreatic Cancer indicate Annamycin’s antitumor activity is partially mediated by CD8+ T cells, supporting a potential immune-mediated mechanism alongside its direct cytotoxic activity

HOUSTON, Sept. 25, 2026 (GLOBE NEWSWIRE) -- Moleculin Biotech, Inc. (NASDAQ:MBRX) ("Moleculin" or the "Company") today announced new preclinical data indicating that the antitumor activity of its lead drug candidate, Annamycin (naxtarubicin), in pancreatic cancer is partially mediated by CD8+ T cell cytotoxicity. The findings are being presented at the AACR Conference on Pancreatic Cancer: New Frontiers in Biology and Therapeutic Development, held September 25–28, 2026 in San Diego, California.

In preclinical models of pancreatic cancer, Annamycin’s antitumor activity appears to depend in part on CD8+ T cells, the immune system’s primary tumor-killing cells. The finding suggests Annamycin may do more than kill cancer cells directly; it may also expose tumors that are typically considered immunologically "cold" to immune attack.

Pancreatic cancer is among the most treatment-resistant solid tumors, and its characteristically "cold" immune microenvironment is one reason checkpoint inhibitors have shown limited single-agent activity in the disease. Preclinical evidence that Annamycin’s activity is partly immune-mediated points to a potential basis for combination approaches, and complements the immune-modulating mechanism of the Company’s WP1066 program.