Effect of Vocimagene Amiretrorepvec in Combination With Flucytosine vs Standard of Care on Survival Following Tumor Resection in Patients With Recurrent High-Grade Glioma: A Randomized Clinical Trial

Abstract

Importance: New treatments are needed to improve the prognosis of patients with recurrent high-grade glioma.

Objective: To compare overall survival for patients receiving tumor resection followed by vocimagene amiretrorepvec (Toca 511) with flucytosine (Toca FC) vs standard of care (SOC).

Design, setting, and participants: A randomized, open-label phase 2/3 trial (TOCA 5) in 58 centers in the US, Canada, Israel, and South Korea, comparing posttumor resection treatment with Toca 511 followed by Toca FC vs a defined single choice of approved (SOC) therapies was conducted from November 30, 2015, to December 20, 2019. Patients received tumor resection for first or second recurrence of glioblastoma or anaplastic astrocytoma.

Interventions: Patients were randomized 1:1 to receive Toca 511/FC (n = 201) or SOC control (n = 202). For the Toca 511/FC group, patients received Toca 511 injected into the resection cavity wall at the time of surgery, followed by cycles of oral Toca FC 6 weeks after surgery. For the SOC control group, patients received investigators' choice of single therapy: lomustine, temozolomide, or bevacizumab.

Main outcomes and measures: The primary outcome was overall survival (OS) in time from randomization date to death due to any cause. Secondary outcomes reported in this study included safety, durable response rate (DRR), duration of DRR, durable clinical benefit rate, OS and DRR by IDH1 variant status, and 12-month OS.

Results: All 403 randomized patients (median [SD] age: 56 [11.46] years; 62.5% [252] men) were included in the efficacy analysis, and 400 patients were included in the safety analysis (3 patients on the SOC group did not receive resection). Final analysis included 271 deaths (141 deaths in the Toca 511/FC group and 130 deaths in the SOC control group). The median follow-up was 22.8 months. The median OS was 11.10 months for the Toca 511/FC group and 12.22 months for the control group (hazard ratio, 1.06; 95% CI 0.83, 1.35; P = .62). The secondary end points did not demonstrate statistically significant differences. The rates of adverse events were similar in the Toca 511/FC group and the SOC control group.

Conclusions and relevance: Among patients who underwent tumor resection for first or second recurrence of glioblastoma or anaplastic astrocytoma, administration of Toca 511 and Toca FC, compared with SOC, did not improve overall survival or other efficacy end points.

Trial registration: ClinicalTrials.gov Identifier: NCT02414165.

Conflict of interest statement

Conflict of Interest Disclosures: Dr Gruber is a member of the board for Tocagen Inc. Drs Rao, Hogan, Accomando, Ostertag, Montellano, Kheoh, and Kabbinavar were Tocagen employees. Dr Cloughesy reported personal fees from Roche, personal fees from Trizel, personal fees from Medscape, personal fees from Bayer, personal fees from Amgen, personal fees from Odonate Therapeutics, personal fees from Pascal Biosciences, personal fees from Del Mar Pharmaceuticals, personal fees from Tocagen, personal fees from Kayopharm, personal fees from GW Pharma, personal fees from Kiyatec, personal fees from AbbVie, personal fees from Boehringer Ingelheim, personal fees from VBL, personal fees from VBI, personal fees from Deciphera, personal fees from Agios, personal fees from QED, personal fees from Merck, personal fees from Genocea, personal fees from Celgene, personal fees from Puma, personal fees from Lilly, and personal fees from BMS outside the submitted work; in addition, Dr Cloughesy had a patent to 62/819322 issued and licensed; and Member of the board for the 501c3 Global Coalition for Adaptive Research and CMO for the entity; Co-founder and board member of Katmai Pharmaceuticals. Dr Petrecca reported other from Tocagen during the conduct of the study. Dr Walbert reported personal fees from Tocagen outside the submitted work. Dr Damek reported grants from Tocagen during the conduct of the study; grants from NovoCure, grants from Kazia Therapeutics, grants from Genentech, grants from Orbus, grants from Roche, and grants from Forma outside the submitted work. Dr Bota reported personal fees from NovoCure and personal fees from Zai Lab outside the submitted work. Dr Bettegowda reported he is a consultant for Depuy-Synthes and Bionaut Pharmaceuticals. The activities associated with those entities are not related to the work presented in this manuscript. Dr Zhu reported grants from Tocagen, Inc and personal fees from Tocagen, Inc during the conduct of the study. Dr Iwamoto reported personal fees from Tocagen during the conduct of the study; personal fees from Merck, personal fees from Guidepoint, grants from BMS, personal fees from NovoCure, personal fees from Alexion, personal fees from AbbVie, and personal fees from Regeneron outside the submitted work. Dr Placantonakis reported personal fees from Tocagen during the conduct of the study; personal fees from Monteris, personal fees from Synaptive, and personal fees from Robeaute outside the submitted work; in addition, Dr Placantonakis had a patent to “Method to treat high grade glioma” pending. Dr Brem reported personal fees from Tocagen during the conduct of the study. Dr Piccioni reported personal fees from Tocagen during the conduct of the study. Dr Chen reported other from Tocagen during the conduct of the study; personal fees from Tocagen outside the submitted work. Dr Gruber reported grants from the US Food and Drug Administration orphan drug grant, other from Apollo Bio, other from Abentis, and other from Denovo Pharma during the conduct of the study; other from Apollo Bio, other from Abentis, and other from Denovo pharma outside the submitted work; in addition, Dr Gruber had a patent to many pending, issued, licensed, and with royalties paid, a patent to many pending, issued, and licensed, and a patent to many pending, issued, and licensed; and Stock and option ownership in Tocagen. Dr Hogan reported other from Tocagen Inc during the conduct of the study. Dr Accomando reported personal fees from Tocagen Inc. during the conduct of the study; personal fees from Tocagen Inc. outside the submitted work. Dr Ostertag reported a patent to US20130130986A1 issued, a patent to US20130323301A1, a patent to US20180021365A1, and a patent to US20140178340A1 . Dr Montellano reported grants from the US Food and Drug Administration Office of Orphan Products Development during the conduct of the study. Dr Kheoh reported other from Tocagen Inc during the conduct of the study. Dr Kabbinavar reported other from Tocagen Inc during the conduct of the study; other from Tocagen outside the submitted work; and Employee of Tocagen Inc. Dr Vogelbaum reported personal fees and other from Tocagen during the conduct of the study; other from Infuseon Theraepeutics and personal fees from Celgene outside the submitted work. No other disclosures were reported.

Figures

Figure 1.. Patient Flow in the TOCA 5 Randomized Clinical Trial

Toca 511 indicates vocimagene amiretrorepvec; Toca FC, flucytosine.

Figure 2.. Kaplan-Meier Overall Survival Curves for Intent-to-Treat Population

Toca indicates vocimagene amiretrorepvec (Toca 511) followed by flucytosine (Toca FC), SOC, standard of care.

Figure 3.. Forest Plot of Preplanned Subgroup Analyses

AA indicates anaplastic astrocytoma; C1D1, cycle 1 day 1; GBM, glioblastoma multiforme; HR, hazard ratio; IDH1, isocitrate dehydrogenase 1; KPS, Karnofsky performance status; MGMT, O6-methylgaunine-DNA-methyltransferase; SOC, standard of care; and Toca, vocimagene amiretrorepvec (Toca 511) followed by flucytosine (Toca FC).