A qualitative evaluation of factors influencing Tumor Treating fields (TTFields) therapy decision making among brain tumor patients and physicians

BACKGROUND

Tumor Treating Fields (TTFields) Therapy is an FDA-approved therapy in the first line and recurrent setting for glioblastoma. Despite Phase 3 evidence showing improved survival with TTFields, it is not uniformly utilized. We aimed to examine patient and clinician views of TTFields and factors shaping utilization of TTFields through a unique research partnership with medical neuro oncology and medical social sciences.

METHODS

Adult glioblastoma patients who were offered TTFields at a tertiary care academic hospital were invited to participate in a semi-structured interview about their decision to use or not use TTFields. Clinicians who prescribe TTFields were invited to participate in a semi-structured interview about TTFields.

RESULTS

Interviews were completed with 40 patients with a mean age of 53 years; 92.5% were white and 60% were male. Participants who decided against TTFields stated that head shaving, appearing sick, and inconvenience of wearing/carrying the device most influenced their decision. The most influential factors for use of TTFields were the efficacy of the device and their clinician's opinion. Clinicians (N = 9) stated that TTFields was a good option for glioblastoma patients, but some noted that their patients should consider the burdens and benefits of TTFields as it may not be the desired choice for all patients.

CONCLUSIONS

This is the first study to examine patient decision making for TTFields. Findings suggest that clinician support and efficacy data are among the key decision-making factors. Properly understanding the path to patients' decision making is crucial in optimizing the use of TTFields and other therapeutic decisions for glioblastoma patients.

CTIM-12. A PHASE 1 TRIAL OF IMMUNORADIOTHERAPY WITH THE IDO ENZYME INHIBITOR (BMS-986205) AND NIVOLUMAB IN PATIENTS WITH NEWLY DIAGNOSED MGMT PROMOTER UNMETHYLATED IDHwt GLIOBLASTOMA

BACKGROUND

IDHwt glioblastoma with unmethylated MGMT gene promoter carries a poor prognosis. Preclinical studies have shown that combination of radiotherapy and dual immunotherapy with nivolumab and IDO inhibition significantly prolongs survival of mice with an orthotopic glioblastoma [Ladomersky, et al. CCR 2018;24(11):2559-2573]. In a clinical trial in patients with newly diagnosed glioblastoma with unmethylated MGMT we substituted temozolomide for dual immunotherapy combination.

METHODS

Phase 1 trial [NCT04047706] using a 3 + 3 dose-escalation design. All received standard radiotherapy (30 x 2 Gy) with addition of once daily oral BMS-986205 and intravenous nivolumab (240mg every 2 weeks) begining on day 1 of radiotherapy and continuing until disease progression or intolerance. BMS-986205 dosing was increased from 50 mg to 100 mg. DLT period encompasses 6 weeks of radiotherapy and the 4 subsequent weeks. Immunocorrelatives being conducted before and after treatment include mass spectrometry for tryptophan and kynurenine levels, immunohistochemistry of resected tumor, and RNA-sequencing and flow cytometric analysis of PBMCs.

RESULTS

Twelve patients were treated on 2 dose levels of BMS-986205 (50, 100 mg). Treatment-emergent toxicity was as expected for this population. Three (25%) treatment-related SAEs were reported. Dose limiting toxicity of grade 3 transaminase elevation was observed in 2 patients at the 100 mg dose level, while at lower doses of BMS-986205 no substantial alterations of liver enzymes was observed. No other relevant treatment related toxicity occured. Ongoing immunocorrelative profiling and preliminary outcome data (all patients minimal follow-up >12 months) will be available at the time of the meeting.

CONCLUSIONS

Dose limiting toxicity of BMS-986205 in combination with nivolumab and radiotherapy is hepatic (reversible) transaminitis. The recommended dose for further investigation is 50 mg. Accrual is ongoing for the MGMT promoter methylated cohort using the same regimen without withholding temozolomide. A randomized phase 2/3 trial is approved within the NRG network.

INNV-13. UNDERSTANDING FACTORS THAT INFLUENCE THE DECISION OF ACCEPTING TUMOR TREATING FIELDS (TTF) THERAPY

BACKGROUND

Tumor Treating Fields (TTF) Therapy is an FDA-approved therapy in the first line and recurrent setting for glioblastoma. Despite Phase 3 evidence showing improved survival, it is not uniformly utilized despite its availability. This qualitative prospective study interviewed glioblastoma patients to better understand key driving factors for decision making.

METHODS

Adult glioblastoma patients who were offered TTF and who signed IRB approved consent were included. Patients participated in a one-time recorded interview with the researchers from the Northwestern University Department of Medical Social Sciences and were asked about factors shaping their decision to use or not use TTF.

RESULTS

40 patients were enrolled with a mean age of 53 years, 92.5% were white and 60% were male. Of the 33 (82.5%) participants who accepted TTF, 23 (69.7%) reported their physician recommending TTF, 8 (24.2%) reported physician neutrality toward TTF, and 2 (6.1%) said their physician advised against TTF. Among the 7 (17.5%) participants who did not choose TTF, 4 (57.1%) reported physician neutrality, 2 (28.6%) reported that their physician advised against TTF, and 1 (14.3%) reported that their physician recommended TTF. Participants who decided against TTF stated that head shaving, appearing sick, and inconvenience of wearing/carrying the device most influenced their decision. For those choosing to use TTF, the most influential factors were extending life and following their doctor's opinion; other factors included level of familial support and the clinical evidence supporting TTF.

DISCUSSION

This clinical study was a collaboration with the Medical Social Sciences team to better understand the key factors that drive patient decision making with TTF. Findings suggest that physician support and positive Phase 3 results are among the key decision-making factors. Properly understanding the path to patients’ decision making is crucial in optimizing use of TTF and other therapeutic decisions for glioblastoma patients.

A first-in-human phase 0 clinical study of RNA interference-based spherical nucleic acids in patients with recurrent glioblastoma

Glioblastoma (GBM) is one of the most difficult cancers to effectively treat, in part because of the lack of precision therapies and limited therapeutic access to intracranial tumor sites due to the presence of the blood-brain and blood-tumor barriers. We have developed a precision medicine approach for GBM treatment that involves the use of brain-penetrant RNA interference-based spherical nucleic acids (SNAs), which consist of gold nanoparticle cores covalently conjugated with radially oriented and densely packed small interfering RNA (siRNA) oligonucleotides. On the basis of previous preclinical evaluation, we conducted toxicology and toxicokinetic studies in nonhuman primates and a single-arm, open-label phase 0 first-in-human trial (NCT03020017) to determine safety, pharmacokinetics, intratumoral accumulation and gene-suppressive activity of systemically administered SNAs carrying siRNA specific for the GBM oncogene Bcl2Like12 (Bcl2L12). Patients with recurrent GBM were treated with intravenous administration of siBcl2L12-SNAs (drug moniker: NU-0129), at a dose corresponding to 1/50th of the no-observed-adverse-event level, followed by tumor resection. Safety assessment revealed no grade 4 or 5 treatment-related toxicities. Inductively coupled plasma mass spectrometry, x-ray fluorescence microscopy, and silver staining of resected GBM tissue demonstrated that intravenously administered SNAs reached patient tumors, with gold enrichment observed in the tumor-associated endothelium, macrophages, and tumor cells. NU-0129 uptake into glioma cells correlated with a reduction in tumor-associated Bcl2L12 protein expression, as indicated by comparison of matched primary tumor and NU-0129-treated recurrent tumor. Our results establish SNA nanoconjugates as a potential brain-penetrant precision medicine approach for the systemic treatment of GBM.