Abstract CT089: Molecular-guided therapy for the treatment of patients with relapsed and refractory childhood cancers: a Beat Childhood Cancer Research Consortium trial
Authors: Sholler Giselle L. Saulner , Kraveka Jacqueline , Bergendahl Genevieve , Lewis Elizabeth , Ferguson William , Nagulapally Abhinav , Dykema Karl , Brown Valerie , Isakoff Michael , Junewick Joseph , Mitchell Deanna , Eslin Don , Harrod Virginia , Roberts William , Oesterheld Javier , Wada Randy , Rawwas Jawhar , Pastakia Devang , Ginn Kevin , Saab Raya , Bielamowicz Kevin , Glover Jason , Chang Eugenia , Hanna Gina , Enriquez Daniel , Izatt Tyler , Halperin Rebecca , Byron Sara , Hendricks William , Trent Jeffrey 
Published: April 2023

Background: Children with relapsed CNS tumors, neuroblastoma, sarcomas, and other rare solid tumors face poor outcomes. Here we describe a study to determine the feasibility of leveraging genomic profiling results within a molecular tumor board (MTB) to make real-time treatment decisions for children with relapsed/refractory solid tumors.

Methods: Subjects were divided to 3 strata: Strata 1: Relapsed/refractory neuroblastoma, Strata 2: Relapsed/refractory CNS tumors, and Strata 3: Relapsed/refractory rare solid tumors. Samples were sent for tumor/normal whole exome (WES) and tumor whole transcriptome sequencing, and the genomic data were used in a MTB to make real-time treatment decisions. The MTB recommended plan allowed for a combination of up to 4 agents. Feasibility was measured by time to completion of genomic sequencing, MTB review and initiation of treatment. Response was assessed after every 2 cycles using Response Evaluation Criteria in Solid Tumors (RECIST). Patient benefit was calculated by the sum of the CR, PR, SD, and NED subjects divided by the sum of CR, PR, SD, NED, and PD subjects. Grade 3 and higher related and unexpected adverse events (AEs) were tabulated for safety evaluation.

Results: 144 eligible subjects were enrolled with 144 evaluable for safety and 124 evaluable for response. Tumor types included neuroblastoma (n=31), CNS tumors (n=41), and rare tumors (n=72). Sarcomas (n=40) were the most common tumor type in the rare tumor stratum. The average time from biopsy to completion of DNA/RNA sequencing was 10 days (range 2-31 days); to completed analysis and drug prediction report, 17 days (8-41); 23 days (10-66) to MTB decisions; and 38 days (18-146) to initiation of the 4-drug combination agreed upon by the MTB. Treatments were selected on DNA and RNA findings in 19.5% of cases and in 80.5% on RNA alone. Patient benefit was exhibited in 70% of all subjects, 85% of neuroblastoma subjects, 73% of CNS tumor subjects, and 62% of rare tumor subjects. AEs occurred in &lt;1% of the subject cohort. Grade 3 leukopenia was the only unexpected hematologic AE. There were 7 occurrences of unexpected non-hematologic AEs: grade 4 elevated ALT (1), grade 3 elevated AST (1), grade 3 dehydration (1), grade 3 infection (2), grade 3 oral mucositis (1), and grade 3 pancreatitis (1).

Conclusions: It has been well-established that comprehensive genomic sequencing is the future of precision medicine. Here, we have demonstrated the feasibility, efficacy, and safety of a comprehensive sequencing model to guide targeted therapy for patients with any relapsed/refractory solid malignancies. Targeted therapy was well tolerated, and the response benefit rate of 70% in these heavily pretreated populations suggests that this treatment could be an effective option for relapsed and refractory pediatric cancers.

Citation Format: Giselle L. Saulner Sholler, Jacqueline Kraveka, Genevieve Bergendahl, Elizabeth Lewis, William Ferguson, Abhinav Nagulapally, Karl Dykema, Valerie Brown, Michael Isakoff, Joseph Junewick, Deanna Mitchell, Don Eslin, Virginia Harrod, William Roberts, Javier Oesterheld, Randy Wada, Jawhar Rawwas, Devang Pastakia, Kevin Ginn, Raya Saab, Kevin Bielamowicz, Jason Glover, Eugenia Chang, Gina Hanna, Daniel Enriquez, Tyler Izatt, Rebecca Halperin, Sara Byron, William Hendricks, Jeffrey Trent. Molecular-guided therapy for the treatment of patients with relapsed and refractory childhood cancers: a Beat Childhood Cancer Research Consortium trial [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 2 (Clinical Trials and Late-Breaking Research); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(8_Suppl):Abstract nr CT089.