STELLAR: Phase III, Randomized, Open-Label Study of Eflornithine Plus Lomustine Versus Lomustine Alone in Patients With Recurrent Grade 3 Astrocytoma

Document Type

Article

Publication Date

3-10-2026

Publication Title

Journal of clinical oncology

Keywords

Humans, Lomustine, Female, Male, Middle Aged, Astrocytoma, Adult, Neoplasm Recurrence, Local, Antineoplastic Combined Chemotherapy Protocols, Brain Neoplasms, Eflornithine, Aged, Neoplasm Grading, Young Adult, Isocitrate Dehydrogenase

Abstract

PURPOSE: STELLAR (ClinicalTrials.gov identifier: NCT02796261) was a phase III, randomized, open-label trial of eflornithine + lomustine versus lomustine monotherapy in patients with recurrent grade 3 astrocytoma.

METHODS: At trial initiation, eligibility criteria included: age ≥18 years, anaplastic astrocytoma (2016 WHO CNS Tumor classification [WHO CNS4]), first recurrence ≥6 months after radiation and temozolomide (TMZ), Karnofsky performance status ≥70, and no imaging findings consistent with grade 4 glioblastoma. Random assignment (1:1) was stratified by isocitrate dehydrogenase (IDH) mutation, age, resection extent, and geography. Patients received eflornithine (2.8 g/m(2) orally, every 8 hours [2 weeks on, 1 week off]) + lomustine (90 mg/m(2) orally, once every 6 weeks), or lomustine monotherapy (110 mg/m(2) once every 6 weeks). The primary end point was overall survival (OS).

RESULTS: Among 343 patients randomly assigned across 74 sites in eight countries, there was no difference in survival between eflornithine + lomustine and lomustine monotherapy (median OS 23.4 v 20.3 months, hazard ratio [HR], 0.94). Following changes in classification and grading in the 2021 WHO CNS5, a subset analysis of patients with IDH-mutant, grade 3 astrocytoma (n = 196), defined in 2024, before unblinding, showed clinically meaningful improvements in median OS with eflornithine + lomustine versus lomustine monotherapy (34.9 v 23.5 months, HR, 0.64) and median progression-free survival (PFS, 15.8 v 7.2 months, HR, 0.57). No differences were observed among patients with CNS grade 4 disease. Grade ≥3 treatment-emergent adverse events of relevance were related to reversible myelosuppression (eflornithine + lomustine 42% v lomustine monotherapy 29% of patients) and hearing impairment (24% v 0%). No new safety signals were identified.

CONCLUSION: Clinically meaningful improvements were observed; eflornithine + lomustine doubled PFS and improved OS in patients with recurrent IDH-mutant, grade 3 astrocytoma, but not grade 4 tumors, after prior radiotherapy and TMZ, consistent with its cytostatic mechanism of action.

Medical Subject Headings

Humans; Lomustine; Female; Male; Middle Aged; Astrocytoma; Adult; Neoplasm Recurrence, Local; Antineoplastic Combined Chemotherapy Protocols; Brain Neoplasms; Eflornithine; Aged; Neoplasm Grading; Young Adult; Isocitrate Dehydrogenase

PubMed ID

41325560

ePublication

ePub ahead of print

Volume

44

Issue

8

First Page

641

Last Page

652

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