Chimerix has announced updated Phase 2 response assessment results for its drug candidate, dordaviprone (ONC201), in the treatment of recurrent H3 K27M-mutant diffuse midline glioma (DMG). The data, evaluated using the Response Assessment in Neuro-Oncology (RANO) 2.0 criteria, revealed a 28.0% overall response rate (ORR) in this difficult-to-treat patient population. These findings will be presented at the 2024 Society for Neuro-Oncology (SNO) Annual Meeting in Houston.
Clinical Efficacy of Dordaviprone
The Phase 2 trial demonstrated not only a significant ORR but also clinically meaningful response times. The median time to response was 4.6 months, and the median duration of response reached 10.4 months. These results suggest that dordaviprone could offer a durable treatment benefit for patients with recurrent H3 K27M-mutant DMG, a rare and aggressive brain tumor with limited therapeutic options.
Allen Melemed, MD, Chief Medical Officer at Chimerix, stated, "This analysis demonstrates an overall response rate of 28.0%, a median time to response of 4.6 months plus a median duration of response of 10.4 months. We expect to include the updated RANO 2.0 results in our planned upcoming New Drug Application to Australian regulators."
Regulatory Pathway and RANO 2.0 Criteria
Chimerix intends to include these updated results in their upcoming New Drug Application to Australian regulators. The adoption of RANO 2.0 criteria is a crucial aspect of this clinical validation. According to Patrick Y. Wen, MD, Director of the Center for Neuro-Oncology at Dana-Farber Cancer Institute, "RANO 2.0 incorporates an integrated quantitative assessment of both enhancing and non-enhancing disease that were not adequately assessed by prior criteria. In addition, it includes minor responses, which in certain regions of the brain, such as midline structures, have disproportionate clinical benefit. This benefit often includes meaningful improvement in neurological symptoms and quality of life outcomes."
Additional Presentations at SNO
In addition to the RANO 2.0 response data, Chimerix will present further pipeline updates at the SNO meeting:
- Title: Allosteric mitochondrial ClpP agonist ONC206 alters stress response, metabolic and epigenetic profiles to elicit anti-cancer efficacy in high-grade gliomas
- Title: Safety of ONC201 treatment in patients with previously treated H3 K27M-mutant glioma: results from ONC028, an ongoing compassionate use program
- Title: Early reduction in MRI diffusion apparent diffusion coefficient (ADC) strongly predicts long term response to ONC201 therapy in patient with H3K27M-DMG
These presentations will cover various aspects of dordaviprone's mechanism of action, safety profile, and predictive biomarkers for treatment response.
About H3 K27M-mutant Diffuse Midline Glioma
H3 K27M-mutant DMG is a particularly aggressive form of glioma that occurs predominantly in children and young adults. The mutation in the H3 K27M gene leads to altered histone methylation, driving tumor growth. The prognosis for patients with this type of glioma is poor, with limited effective treatment options available. Dordaviprone represents a potential new therapeutic avenue for these patients.
