Tumor Treating Fields (TTFields) Therapy and Lomustine Chemotherapy for the Treatment of Unresectable Progressive Glioblastoma.

Introduction: Tumor Treating Fields (TTFields) therapy used concomitantly with maintenance temozolomide through second progression after radio-chemotherapy is associated with improved survival outcomes compared to adjuvant temozolomide alone in individuals with newly diagnosed glioblastoma (GBM). Lomustine (CCNU) is frequently used as monotherapy or concomitant with other chemotherapy regimens as second-line treatment for recurrent GBM.

Case Presentation: We report a 59-year-old female patient diagnosed with -promoter methylated, isocitrate dehydrogenase-wildtype GBM (World Health Organization Grade 4) who received TTFields therapy concomitant with first- and second-line chemotherapy following partial resection. The patient experienced tumor pseudoprogression/progression after three cycles of maintenance temozolomide/TTFields therapy and again after a further two cycles of procarbazine/CCNU/TTFields therapy, and was then switched to CCNU/TTFields therapy. During 18 months of treatment with concomitant TTFields therapy and CCNU, the patient experienced regression/reduction of both tumor volume and perifocal edema with tolerable hematotoxicity and was able to maintain a high rate of TTFields therapy usage. The patient ultimately died after developing chemotherapy-related acute myeloid leukemia.

Conclusion: This patient case is reflective of the EF-14 study outcome using TTFields therapy beyond first progression concomitantly with chemotherapy. The observations from this case suggest that TTFields therapy concomitant with CCNU is a valuable treatment modality in patients with GBM, in this context.