Evaluation of Durable Response Rate in the Post-resection Setting and Association with Survival in Patients with Recurrent High Grade Glioma Who Received Vocimagene Amiretroprepvec and 5-Fluorocytosine Treatment

Newswise — Bob S. Carter, MD, PhD, FAANS, presented results today from a new research study, Evaluation of Durable Response Rate in the Post-Resection Setting and Association with Survival in Patients with Recurrent High Grade Glioma Who Received Vocimagene Amiretroprepvec and 5-Fluorocytosine Treatment, during the 2018 American Association of Neurological Surgeons (AANS) Annual Scientific Meeting. Dr. Carter received the Journal of Neuro-Oncology Award, which was accepted on behalf of the co-authors of the study.

Vocimagene amiretrorepvec is an investigational retroviral replicating vector that selectively infects dividing cancer cells, integrates into the genome and replicates due to immune defects in tumors. Vocimagene amiretrorepvec spreads through tumors and stably delivers the gene, encoding an optimized yeast cytosine deaminase that converts the prodrug 5-fluorocytosine (an investigational, extended-release formulation of 5-fluorocytosine) into 5-fluorouracil, which kills infected and nearby cancer cells, myeloid derived suppressor cells and tumor associated macrophages, thus enabling immune activity against the tumor.

Complete responses (CR)s were observed in patients with IDH1 mutant and wildtype tumors, suggesting a benefit across the rHGG setting. Data suggests a positive association of durable response with overall survival.

In this phase 1 trial (NCT01470794), ascending doses of vocimagene amiretrorepvec were injected into the resection cavity wall of patients with rHGG who had chosen to undergo a further resection, followed by multiple courses of oral 5-fluorocytosine. Additional cohorts included combination of investigational therapy with bevacizumab or lomustine.

Objective responses (ORs) were assessed by independent radiology review using MRI images prior to 5-fluorocytosine treatment as baseline. ORs occurred 6-19 months after vocimagene amiretrorepvec administration, suggesting an immunologic mechanism. The ORs were observed in four patients with IDH1 wildtype and two with IDH1 mutant tumors, including five CRs with the investigational therapy, and 1 CR with the investigational therapy and bevacizumab. The median duration of response (mDoR) was 35.1+ months. Excluding combination cohorts, mDoR was 35.7+ months. As of 8/15/2017, all responders were in CR and alive. In a 23-patient subgroup who received the recommended Ph3 vocimagene amiretrorepvec dose, mOS was 14.4 months, 3-year survival rate was 26.1 percent and a durable response rate of 21.7 percent was observed. Across the Ph1 program, the safety profile remains favorable.

Author Block: Timothy Cloughesy, MD; Joseph Landolfi, DO; Michael Vogelbaum, MD, PhD; Brad Elder, MD; Clark Chen, MD, PhD.; Steven Kalkanis, MD; Santosh Kesari, MD, PhD.; Ian Lee, MD; David Piccioni, MD, PhD.; Tobias Walbert, MD, PhD.

Disclosure: The author reported no conflicts of interest.

Media Representatives: The 2018 AANS Annual Scientific Meeting website’s press section will include releases on highlighted scientific research, AANS officers and award winners, Neurosurgery Awareness Month and other relevant information about the 2018 program. Releases will be posted on the 2018 AANS Annual Scientific Meeting website. If you have interest in a topic related to neurosurgery or would like to interview a neurosurgeon — either onsite or via telephone — during the event, please contact Alice Kelsey, AANS associate executive director, via email at [email protected].

About the 2018 AANS Annual Scientific Meeting: Attended by neurosurgeons, neurosurgical residents, medical students, neuroscience nurses, clinical specialists, physician assistants, allied health professionals and other medical professionals, the AANS Annual Scientific Meeting is the largest gathering of neurosurgeons in the nation, with an emphasis on the field’s latest research and technological advances. The scientific presentations accepted for the 2018 event will represent cutting-edge examples of the incredible developments taking place within the field of neurosurgery. Find additional information about the 2018 AANS Annual Scientific Meeting and the meeting program here.

Founded in 1931 as the Harvey Cushing Society, the American Association of Neurological Surgeons (AANS) is a scientific and educational association with more than 11,000 members worldwide. The AANS is dedicated to advancing the specialty of neurological surgery in order to provide the highest quality of neurosurgical care to the public. Fellows of the AANS are board-certified by the American Board of Neurological Surgery, the Royal College of Physicians and Surgeons of Canada or the Mexican Council of Neurological Surgery, A.C. Neurosurgery is the medical specialty concerned with the prevention, diagnosis, treatment and rehabilitation of disorders that affect the spinal column, spinal cord, brain, nervous system and peripheral nerves.

For more information, visit www.AANS.org.