Chimerix, Inc. announced the successful launch of the ONC201 Phase 3 ACTION study at the recent Society for Neuro Oncology (SNO) Conference, which took place November 16-20, 2022 in Tampa, Florida. These data support a potentially meaningful overall survival (OS) advantage for ONC201 in the recurrent setting. Additionally, two analyses presented by external parties at the SNO conference reported meaningful OS advantages for ONC201-treated patients in frontline and recurrent settings relative to external controls derived from clinical trials, institutional experiences, and real-world evidence.

Additionally, as near completion of the transition of TEMBEXA(R) to Emergent BioSolutions, reducing the size of the organization by approximately 25% in order to focus its development capability and capital allocation to its oncology pipeline. The company is thankful for the commitment of these talented employees who have contributed so much to the Company. The company will be working closely with those affected to support them in this transition.

The Company also evaluated objective response by RANO-HGG criteria in patients who received therapies other than ONC201 but met similar selection criteria used for the Phase 2 analysis of ONC201 designed to isolate single agent responses. In the two patients who were evaluable, neither achieved an objective response. The low number of patients who qualified was primarily due to the high prevalence of ONC201, bevacizumab and radiotherapy use during that period of relapse, which would confound an objective response determination.

The company plans to present a more comprehensive analysis of the Natural Disease History study at a future scientific conference. Two External Presentations at SNO Report an OS Advantage in Patients Who Received ONC201 Overall survival analyses indicating superior outcomes for patients who received ONC201, either prior to or after disease progression, compared to patients who never received ONC201, were reported at SNO by a team of academic investigators who evaluated clinical trials and institutional experiences in the United States and Europe. For patients who received ONC201 prior to disease progression, the same treatment setting being evaluated in the Phase 3 ACTION study, the median OS for patients who received ONC201 was 26.3 months (n=35).

This was compared to 12 months for patients who did not receive ONC201 (n=274, p<0.0001). In the recurrent setting, patients treated with ONC201 (n=37) had a median overall survival of 16.2 months compared to 8.1 months for those not treated with ONC201 (n=99, p=0.05). Authors concluded that ONC201 efficacy was enriched in patients treated prior to recurrence.(i) Separately, a poster presentation at SNO from xCures evaluated real world outcomes and treatment patterns among patients with DMG, which also concluded ONC201 meaningfully extends OS in patients with DMG.(ii) About the Phase 3 ACTION Study The ACTION trial enrolls patients shortly after they have completed front-line radiation therapy that is the standard of care.