LOUISVILLE – October 28, 2026 -- US WorldMeds Ventures, LLC has acquired Orbus Therapeutics, Inc., adding a late-stage eflornithine program for recurrent Grade 3 astrocytoma. In a prespecified subset of the Phase 3 STELLAR study, patients with IDH-mutant disease reached median overall survival of 34.9 months, versus 23.5 months on lomustine alone.
US WorldMeds made an undisclosed upfront payment under a definitive merger agreement. Orbus is eligible for development, regulatory and sales-based milestone payments, plus tiered royalties on U.S. net sales. It is now a wholly owned subsidiary of US WorldMeds.
STELLAR missed its primary endpoint in the full study population
The 343-patient trial compared eflornithine plus lomustine with lomustine alone in recurrent Grade 3 astrocytoma, defined under the 2016 WHO classification. It showed no overall survival difference between arms in the intent-to-treat population, which was the primary endpoint.
A subset analysis, defined before unblinding, applied the 2021 WHO reclassification criteria. It covered 196 patients with IDH-mutant Grade 3 astrocytoma. No benefit appeared in patients with Grade 4 tumors under the updated classification.
IDH-mutant subset shows hazard ratios of 0.64 for survival and 0.57 for progression
In the IDH-mutant Grade 3 subset, median overall survival was 34.9 months with eflornithine plus lomustine, against 23.5 months with lomustine alone (hazard ratio 0.64). Median progression-free survival by investigator assessment more than doubled, to 15.8 months from 7.2 months (hazard ratio 0.57).
The combination carried higher toxicity. Grade 3 or higher myelosuppression occurred in 42% of patients versus 29%, and hearing impairment in 24% versus 0%. The results were published in the Journal of Clinical Oncology (Colman et al., 2026).
US WorldMeds plans FDA talks after Breakthrough Therapy designation
FDA has granted the eflornithine program Breakthrough Therapy designation for anaplastic astrocytoma. US WorldMeds already sells IWILFIN (eflornithine 192 mg tablets) for a separate rare oncology indication. The STELLAR results, however, were achieved with an oral solution formulation developed by Orbus.
Eflornithine is investigational for glioma. Neither FDA nor any other regulator has approved it for this use, and its safety and efficacy in glioma are not established.
US WorldMeds will evaluate the development and regulatory path in recurrent IDH-mutant Grade 3 astrocytoma and other adult malignant glioma opportunities. CEO P. Breckinridge Jones said the company wants to "responsibly evaluate eflornithine's potential" and expects to engage FDA on the best path forward.