Synapse - Phase 1 study of intraventricular (131)I-omburtamab targeting B7H3 (CD276)-expressing CNS malignancies

Phase 1 study of intraventricular (131)I-omburtamab targeting B7H3 (CD276)-expressing CNS malignancies Journal Article

Authors:	Kramer, K.; Pandit-Taskar, N.; Kushner, B. H.; Zanzonico, P.; Humm, J. L.; Tomlinson, U.; Donzelli, M.; Wolden, S. L.; Haque, S.; Dunkel, I.; Souweidane, M. M.; Greenfield, J. P.; Tickoo, S.; Lewis, J. S.; Lyashchenko, S. K.; Carrasquillo, J. A.; Chu, B.; Horan, C.; Larson, S. M.; Cheung, N. K. V.; Modak, S.
Article Title:	Phase 1 study of intraventricular (131)I-omburtamab targeting B7H3 (CD276)-expressing CNS malignancies
Abstract:	Background: The prognosis for metastatic and recurrent tumors of the central nervous system (CNS) remains dismal, and the need for newer therapeutic targets and modalities is critical. The cell surface glycoprotein B7H3 is expressed on a range of solid tumors with a restricted expression on normal tissues. We hypothesized that compartmental radioimmunotherapy (cRIT) with the anti-B7H3 murine monoclonal antibody omburtamab injected intraventricularly could safely target CNS malignancies. Patients and methods: We conducted a phase I trial of intraventricular 131I-omburtamab using a standard 3 + 3 design. Eligibility criteria included adequate cerebrospinal fluid (CSF) flow, no major organ toxicity, and for patients > dose level 6, availability of autologous stem cells. Patients initially received 74 MBq radioiodinated omburtamab to evaluate dosimetry and biodistribution followed by therapeutic 131I-omburtamab dose-escalated from 370 to 2960 MBq. Patients were monitored clinically and biochemically for toxicity graded using CTCAEv 3.0. Dosimetry was evaluated using serial CSF and blood sampling, and serial PET or gamma-camera scans. Patients could receive a second cycle in the absence of grade 3/4 non-hematologic toxicity or progressive disease. Results: Thirty-eight patients received 100 radioiodinated omburtamab injections. Diagnoses included metastatic neuroblastoma (n = 16) and other B7H3-expressing solid tumors (n = 22). Thirty-five patients received at least 1 cycle of treatment with both dosimetry and therapy doses. Acute toxicities included < grade 4 self-limited headache, vomiting or fever, and biochemical abnormalities. Grade 3/4 thrombocytopenia was the most common hematologic toxicity. Recommended phase 2 dose was 1850 MBq/injection. The median radiation dose to the CSF and blood by sampling was 1.01 and 0.04 mGy/MBq, respectively, showing a consistently high therapeutic advantage for CSF. Major organ exposure was well below maximum tolerated levels. In patients developing antidrug antibodies, blood clearance, and therefore therapeutic index, was significantly increased. In patients receiving cRIT for neuroblastoma, survival was markedly increased (median PFS 7.5 years) compared to historical data. Conclusions: cRIT with 131I-omburtamab is safe, has favorable dosimetry and may have a therapeutic benefit as adjuvant therapy for B7-H3-expressing leptomeningeal metastases. Trial registration: clinicaltrials.gov NCT00089245, August 5, 2004. © 2022, The Author(s).
Keywords:	clinical trial; mouse; animal; animals; mice; neoplasm recurrence, local; central nervous system tumor; central nervous system neoplasms; monoclonal antibody; antibodies, monoclonal; tissue distribution; neuroblastoma; tumor recurrence; phase 1 clinical trial; drug therapy; radioimmunotherapy; b7 antigen; cns metastases; cns tumors; iodine-131; cd276 protein, human; b7 antigens; humans; human; omburtamab; b7h3
Journal Title:	Journal of Hematology & Oncology
Volume:	15
ISSN:	1756-8722
Publisher:	Biomed Central Ltd
Date Published:	2022-11-12
Start Page:	165
Language:	English
DOI:	10.1186/s13045-022-01383-4
PUBMED:	36371226
PROVIDER:	scopus
PMCID:	PMC9655863
DOI/URL:	https://www.scopus.com/inward/record.uri?eid=2-s2.0-85141670285&doi=10.1186%2fs13045-022-01383-4&partnerID=40&md5=96da88dd1b538145b0fd63fc7c716665
Notes:	PDF misspells the author: Sofia Haque's first name -- Source: Scopus