Abstract Toca 511 (vocimagene amiretroprepvec) is an investigational, conditionally lytic, retroviral replicating vector that encodes an optimized yeast cytosine deaminase (CD) gene. The CD gene converts the prodrug, Toca FC (investigational, extended-release 5-fluorocytosine), into the chemotherapeutic, 5-FU in infected tumors. In a Phase 1 study (NCT01985256), Toca 511 was injected intravenously for 1, 3, or 5 days to patients with recurrent high grade glioma. Tumors were subsequently resected, and Toca 511 was injected into the resection cavity walls. At the time of resection, tissue from various regions of the tumor was collected and processed for quantitative PCR analysis of CD RNA and DNA. Tissue from corresponding locations was fixed for assessment of CD protein expression by immunohistochemistry (IHC). Expression of CD protein was quantified based on immunofluorescence signal and was shown to co-localize in cells with detectable levels of gag, a viral structural protein. CD protein expression by IHC was assessed in tissue from locations that corresponded with samples positive for CD by PCR and ranged from 1.16% to 10.4% area of the field. These data show that intravenous delivery of Toca 511 results in appreciable deposition of vector in the tumor. Further, we have observed an inverse correlation between T cell infiltrate in the tumor microenvironment and clinical benefit in a complementary Phase I study in which Toca 511 was solely delivered into the resection cavity. Therefore, the nature of the study design described herein, which uses IV delivery of Toca 511, provides a unique opportunity to assess the spatial relationship between CD protein expression and histological features of the tumor. Immunohistochemical assessment to determine spatial correlates between CD protein and T cells, T regulatory cells, and immunosuppressive myeloid cells will be presented. Updated clinical response data will also be presented.

BACKGROUND: Few studies have evaluated the health-related quality of life (HRQoL) of patients with meningiomas. Here, we report the largest prospective, longitudinal cross-sectional cohort study of HRQoL in meningiomas to date, in order to identify possible actionable determinants of global HRQoL. METHODS: Adults who had undergone resection of a grade I intracranial meningioma and were in routine follow-up at a single large tertiary center underwent HRQoL assessment using the QLQ-C30 questionnaire administered opportunistically at follow-up visits. Averaged transformed QLQ-C30 scores at 12-month intervals were compared with scores from a normative reference population, with reference to known minimal clinically meaningful difference (CMD) in scores. To evaluate for possible determinants of changes in global HRQoL, global HRQoL scores were correlated (Spearmans Rho) with subdomain and symptom scores and with interval time from surgical resection. RESULTS: A total of 291 postoperative patients with histologically confirmed and surgically treated grade I meningiomas consented to participation and a total of 455 questionnaires were included for analysis. Patients with meningiomas reported reduced global HRQoL at nearly every 12-month interval with clinically and statistically significant impairments at 12, 48, 108, and 120 months postoperative compared with the normative population (P < 0.05). Meningioma patients at the 12-month interval also reported a reduction of each subdomain of HRQoL assessment (P < 0.05); however, a CMD was only seen in cognitive functioning. Physical, emotional, cognitive, and social subdomains, as well as fatigue and sleep/insomnia, were significantly associated with global HRQoL at the first 12-month interval. Overall, there was no significant correlation between time from surgery and global HRQoL or the subdomain functional or symptom sections of the QLQ-C30. CONCLUSIONS: Meningioma patients report considerable limitations in HRQoL for more than 120 months after surgery, particularly in cognitive, emotional, and social function, as well as suffering significant fatigue and sleep impairment compared with a normative reference population. The majority of these reported functional impairments and symptoms are strongly associated with global HRQoL and thus can be considered determinants of global HRQoL that if treated, have the potential to improve HRQoL for our meningioma patients. This hypothesis requires future study of targeted interventions to determine their efficacy.

Building on an initiative to enhance clinical trial participation involving the Society for Neuro-Oncology, the Response Assessment in Neuro-Oncology Working Group, patient advocacy groups, clinical trial cooperative groups, and other partners, we evaluate the impact of eligibility criteria and trial conduct on neuro-oncology clinical trial participation. Clinical trials often carry forward eligibility criteria from prior studies that may be overly restrictive and unnecessary and needlessly limit patient accrual. Inclusion and exclusion criteria should be evaluated based on the goals and design of the study and whether they impact patient safety and/or treatment efficacy. In addition, we evaluate clinical trial conduct as a barrier to accrual and discuss strategies to minimize such barriers for neuro-oncology trials.

Background

Vocimagene amiretrorepvec (Toca 511) is an investigational gamma-retroviral replicating vector encoding cytosine deaminase that, when used in combination with extended-release 5-fluorocytosine (Toca FC), results preclinically in local production of 5-fluorouracil, depletion of immune-suppressive myeloid cells, and subsequent induction of antitumor immunity. Recurrent high-grade glioma (rHGG) patients have a high unmet need for effective therapies that produce durable responses lasting more than 6 months. In this setting, relapse is nearly universal and most responses are transient.

Methods

In this Toca 511 ascending-dose phase I trial (NCT01470794), HGG patients who recurred after standard of care underwent surgical resection and received Toca 511 injected into the resection cavity wall, followed by orally administered cycles of Toca FC.

Results

Among 56 patients, durable complete responses were observed. A subgroup was identified based on Toca 511 dose and entry requirements for the follow-up phase III study. In this subgroup, which included both isocitrate dehydrogenase 1 (IDH1) mutant and wild-type tumors, the durable response rate is 21.7%. Median duration of follow-up for responders is 35.7+ months. As of August 25, 2017, all responders remain in response and are alive 33.9+ to 52.2+ months after Toca 511 administration, suggesting a positive association of durable response with overall survival.

Conclusions

Multiyear durable responses have been observed in rHGG patients treated with Toca 511 + Toca FC in a phase I trial, and the treatment will be further evaluated in a randomized phase III trial. Among IDH1 mutant patients treated at first recurrence, there may be an enrichment of complete responders.

Background

The Response Assessment in Neuro-Oncology Patient-Reported Outcome (RANO-PRO) working group aims to provide guidance on the use of PROs in brain tumor patients. PRO measures should be of high quality, both in terms of relevance and other measurement properties. This systematic review aimed to identify PRO measures that have been used in brain tumor studies to date.

Methods

A systematic literature search for articles published up to June 25, 2020 was conducted in several electronic databases. Pre-specified inclusion criteria were used to identify studies using PRO measures assessing symptoms, (instrumental) activities of daily living [(I)ADL] or health-related quality of life (HRQoL) in adult patients with glioma, meningioma, primary central nervous system lymphoma, or brain metastasis.

Results

A total of 215 different PRO measures were identified in 571 published and 194 unpublished studies. The identified PRO measures include brain tumor-specific, cancer-specific, and generic instruments, as well as instruments designed for other indications or multi- or single-item study-specific questionnaires. The most frequently used instruments were the EORTC QLQ-C30 and QLQ-BN20 (n = 286 and n = 247), and the FACT-Br (n = 167), however, the majority of the instruments were used only once or twice (150/215).

Conclusion

Many different PRO measures assessing symptoms, (I)ADL or HRQoL have been used in brain tumor studies to date. Future research should clarify whether these instruments or their scales/items exhibit good content validity and other measurement properties for use in brain tumor patients.

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.

Toca 511 (vocimagene amiretrorepvec) is an investigational nonlytic, retroviral replicating vector (RRV) that delivers a yeast cytosine deaminase, which converts subsequently administered courses of the investigational prodrug Toca FC (extended-release 5-fluorocytosine) into the antimetabolite 5-fluorouracil. Forty-five subjects with recurrent or progressive high-grade glioma were treated. The end points of this phase 1, open-label, ascending dose, multicenter trial included safety, efficacy, and molecular profiling; survival was compared to a matching subgroup from an external control. Overall survival for recurrent high-grade glioma was 13.6 months (95% confidence interval, 10.8 to 20.0) and was statistically improved relative to an external control (hazard ratio, 0.45; P = 0.003). Tumor samples from subjects surviving more than 52 weeks after Toca 511 delivery disproportionately displayed a survival-related mRNA expression signature, identifying a potential molecular signature that may correlate with treatment-related survival rather than being prognostic. Toca 511 and Toca FC show excellent tolerability, with RRV persisting in the tumor and RRV control systemically. The favorable assessment of Toca 511 and Toca FC supports confirmation in a randomized phase 2/3 trial (NCT02414165).

Toca 511 (vocimagene amiretrorepvec) is an investigational nonlytic, retroviral replicating vector (RRV) that delivers a yeast cytosine deaminase, which converts subsequently administered courses of the investigational prodrug Toca FC (extended-release 5-fluorocytosine) into the antimetabolite 5-fluorouracil. Forty-five subjects with recurrent or progressive high-grade glioma were treated. The end points of this phase 1, open-label, ascending dose, multicenter trial included safety, efficacy, and molecular profiling; survival was compared to a matching subgroup from an external control. Overall survival for recurrent high-grade glioma was 13.6 months (95% confidence interval, 10.8 to 20.0) and was statistically improved relative to an external control (hazard ratio, 0.45; P = 0.003). Tumor samples from subjects surviving more than 52 weeks after Toca 511 delivery disproportionately displayed a survival-related mRNA expression signature, identifying a potential molecular signature that may correlate with treatment-related survival rather than being prognostic. Toca 511 and Toca FC show excellent tolerability, with RRV persisting in the tumor and RRV control systemically. The favorable assessment of Toca 511 and Toca FC supports confirmation in a randomized phase 2/3 trial (NCT02414165).