On April 23, 2026 Moleculin Biotech, Inc., (Nasdaq: MBRX) ("Moleculin" or the "Company"), reported the presentation of new preclinical data at the American Association for Cancer Research (AACR) (Free AACR Whitepaper) Annual Meeting 2026 highlighting the potential of its lead drug candidate, Annamycin, in pancreatic cancer.
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"We are highly encouraged by these results, which demonstrate compelling anti-tumor activity in pancreatic cancer models. Importantly, these findings are consistent with the effects we continue to observe with Annamycin in AML," said Walter Klemp, Chairman and Chief Executive Officer of Moleculin. "This consistency across both hematologic and solid tumor settings reinforces our confidence in Annamycin’s underlying mechanism."
"It is important to highlight that the clinical landscape continues to reflect the trend toward increased use of combination therapies, especially those that combine innovative targeted mechanisms with time-tested cytotoxic payloads. It’s in these settings that Annamycin’s potential may be at its greatest considering its lack of cardiotoxicity, greater tolerability and ability to avoid resistance mechanisms. We believe these data underscore Annamycin’s potential to expand into additional high-need cancer indications," added Mr. Klemp
The data demonstrate that liposomal Annamycin (L-ANN), a novel, non-cardiotoxic anthracycline, produced significant tumor growth inhibition across multiple pancreatic ductal adenocarcinoma (PDAC) models, including orthotopic human PDAC and syngeneic systems, with strong statistical significance (p < 0.001). These findings were accompanied by a meaningful survival benefit in a metastatic model, where treatment extended median survival by more than 60% compared to control (29 days versus 18 days; p = 0.0003), underscoring the potential clinical relevance of L-ANN in aggressive disease settings.
Pharmacokinetic analyses further demonstrated enhanced tumor penetration and retention of Annamycin compared to doxorubicin, with significantly higher accumulation observed in pancreatic tissue and tumors (p<0.0001). These data provide a mechanistic basis for the observed anti-tumor activity and highlight a key differentiating feature of Annamycin relative to traditional anthracyclines, which have historically shown limited efficacy in pancreatic cancer.
In addition to its direct cytotoxic effects, L-ANN was shown to induce immune activation within the tumor microenvironment, including increased infiltration of CD8+ cytotoxic T cells and CD4+ helper T cells. These findings suggest the potential for Annamycin to convert immunologically "cold" pancreatic tumors into more responsive phenotypes, supporting its evaluation both as a monotherapy and in combination with other drugs, including immune checkpoint and KRAS inhibitors.
Consistent with prior studies, Annamycin also demonstrated a favorable safety profile, including the absence of cardiotoxicity, a well-documented limitation of conventional anthracyclines such as doxorubicin. This differentiated safety profile may enable broader therapeutic use and synergistic combination strategies.
The Company is currently evaluating Annamycin in combination with cytarabine (Ara-C), collectively referred to as AnnAraC, in its pivotal Phase 2B/3 "MIRACLE" trial for the treatment of adult patients with relapsed or refractory acute myeloid leukemia (R/R AML) following induction therapy. The MIRACLE trial is a global, adaptive Phase 2B/3 clinical study being conducted across the United States, Europe, and other international sites.
These data were presented at the American Association for Cancer Research (AACR) (Free AACR Whitepaper) Annual Meeting 2026.
(Press release, Moleculin, APR 23, 2026, View Source [SID1234664724])