Combined SSTR2-targeted Analogue with ¹⁷⁷Lu-DOTATATE radionuclide and octreotide therapy for refractory meningioma: a...

Meningiomas are the most common primary intracranial tumor in adults. Beyond surgery and radiation, no standard of care therapy exists. Meningiomas overexpress somatostatin receptor 2 (SSTR2), providing the rationale for somatostatin analogue-based therapies, including octreotide. The addition of everolimus, a mammalian target of rapamycin inhibitor, to octreotide marginally improves the 6-month progression-free survival (PFS) rate. For this reason, novel therapies have emerged for the treatment of refractory meningiomas, including somatostatin receptor targeted radionuclide therapy. However, preliminary results with refractory meningiomas treated with single agent ¹⁷⁷Lu-DOTATATE, a β-emitting peptide receptor radionuclide therapy (PRRT), demonstrated outcomes comparable to those observed with combination octreotide and everolimus. In contrast, in neuroendocrine tumors (NETs), octreotide combined with PRRT has shown significant prolongation of PFS compared to high-dose octreotide alone. The final analysis of the NETTER-1 trial also yielded a trend towards an improvement in median overall survival, supporting the FDA approval of ¹⁷⁷Lu-DOTATATE in 2018 for use in NETs. We present the first case of a refractory meningioma patient treated with combination PRRT and octreotide in a 66-year-old male who received ¹⁷⁷Lu-DOTATATE 7.4 GBq (200 mCi) and intramuscular long-acting octreotide 40 mg every 8 weeks for four cycles followed by a single cycle of octreotide 40 mg monotherapy. Treatment was discontinued due to his unfortunate death from non-treatment related causes, occurring 2.5 months from his final octreotide dose. A 7-week post-treatment MRI brain demonstrated stable disease with 11.5% reduction per RANO-Meningioma and a 2.6% reduction per RECIST 1.1 criteria. Combined PRRT and octreotide represents a promising therapeutic strategy for patients with refractory meningioma.