Onconic Therapeutics presented preclinical research results for its anticancer drug candidate "Nesuparib," targeting small cell lung cancer (SCLC), at the American Association for Cancer Research (AACR 2026) meeting held in San Diego on Thursday (local time). This marks the first public release of preclinical data on Nesuparib.
Onconic Therapeutics said the results demonstrated that Nesuparib delivers enhanced antitumor effects compared with existing therapies and features a differentiated multi-mechanism of action. SCLC is considered one of the most intractable cancers due to its high proliferation rate and rapid recurrence. As a result, the need for powerful tumor suppression and approaches based on novel mechanisms has been continuously raised.
In the study, Nesuparib showed cancer cell growth inhibition up to 133 times stronger than olaparib, an existing poly ADP-ribose polymerase (PARP) inhibitor, and approximately 25 times stronger than irinotecan, an anticancer drug used to treat SCLC, when administered alone in an in vitro SCLC cell line model. In a xenograft animal model experiment, it recorded a tumor inhibition rate of 66.5%, showing higher antitumor effects compared with olaparib (36%) and irinotecan (42.9%). The study also confirmed that high tumor suppression effects were maintained when Nesuparib was combined with irinotecan, even at reduced doses.
The differentiation of Nesuparib's multi-mechanism action was also demonstrated. Nesuparib significantly reduced c-Myc and Ki-67, which are characteristically highly expressed in SCLC, through its multi-mechanism action. This suggests that Nesuparib could go beyond simple tumor growth inhibition to regulate the core proliferation mechanisms of tumors.
"Nesuparib has confirmed the potential to complement the limitations of existing treatment approaches through its multi-mechanism action," an Onconic Therapeutics official said. "In particular, as it has been confirmed to simultaneously inhibit c-Myc and YAP proteins, which are key tumor-driving factors, we expect it to develop into a treatment strategy applicable to various molecular subtypes of SCLC."
Nesuparib received Orphan Drug Designation from the U.S. Food and Drug Administration (FDA) for the treatment of SCLC in February. Onconic Therapeutics plans to accelerate clinical development based on these research results.
