BeyondSpring Inc. (NASDAQ: BYSI) presented preclinical data at the 2026 American Association for Cancer Research Annual Meeting showing that Plinabulin enhanced the efficacy and tolerability of antibody-drug conjugate therapy in laboratory studies.

The data demonstrated that Plinabulin, when combined with two approved ADCs - trastuzumab deruxtecan and datopotamab deruxtecan - produced complete tumor regressions and improved survival in animal models compared to ADC treatment alone. The combinations also reduced animal death rates in both two-drug and three-drug regimens that included PD-1 inhibitors.

According to the company, Plinabulin works through a GEF-H1 agonist mechanism that activates immune cells, signals blood cell replenishment, and disrupts tumor blood supply. Analysis showed the drug enhanced CD8+ T cell/Treg ratios, indicating immune system activation.

The preclinical results build on BeyondSpring's Phase 3 DUBLIN-3 study published in The Lancet Respiratory Medicine in 2024, where Plinabulin combined with docetaxel chemotherapy doubled survival rates in certain lung cancer patients while reducing severe neutropenia from 33% to 5%.

BeyondSpring plans to advance its DUBLIN-4 confirmatory Phase 3 trial, a 442-patient study in non-small cell lung cancer patients who have progressed on immune checkpoint inhibitors. The company stated the new ADC data supports potential future combination studies beyond the confirmatory program.

"Plinabulin has the potential to enable ADC therapy to deliver on its full promise - producing more complete responses, extending survival, and keeping patients on treatment," said Dr. Lan Huang, the company's chairman and CEO.

Over 700 cancer patients have been treated with Plinabulin across clinical studies, according to the company's press release statement.