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

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.

Local Anesthesia With General Anesthesia for Pediatric Bone Marrow Procedures.

BACKGROUND: Pediatric patients with cancer undergo repeated painful procedures, including bone marrow aspirations and biopsies (BMABs). Optimal management of procedure-related pain can reduce discomfort, anxiety, and distress. METHODS: Children with neuroblastoma were randomly assigned to 1 of 2 arms on a prospective, single-blind, crossover trial conducted at Memorial Sloan Kettering Cancer Center from October 2016 to January 2018 (www.clinicaltrials.gov, identifier NCT02924324). Participants underwent 2 sequential BMABs: one with general anesthesia (GA) alone, the other with GA plus local anesthesia (LA) (GA + LA). The objective was to assess procedure-related pain and its interference with quality of life (QoL) with GA versus GA + LA. Primary outcome was percentage of participants requiring postprocedural opioids. Secondary outcomes were total opioid and nonopioid analgesics, pain scores, time to first analgesic, QoL, and toxicity. Management of postprocedural pain was standardized. RESULTS: Of 56 participants randomly assigned (3-16.5 years old), 46 completed both procedures. There was no significant difference in percentage of participants requiring opioids with GA versus GA + LA (24% vs 20%, P = .5). Pain scores in the recovery room were significantly lower for GA + LA versus GA (median [IQR]: 0 [0-2] vs 2 [0-4], P = .002). There were no statistically significant differences in total opioid or nonopioid analgesic, 6- and 24-hour pain scores, median time to first analgesic, or pain interference. No adverse events occurred. CONCLUSIONS: LA was associated with significant improvement in pain scores in the immediate recovery period. LA did not reduce postprocedural opioid use, nor did it improve QoL for patients undergoing BMAB with GA.

Feasibility of Administering High-Dose (131) I-MIBG Therapy to Children with High-Risk Neuroblastoma Without Lead-Lined Rooms.

BACKGROUND: Although (131) I-metaiodobenzylguanidine ((131) I-MIBG) therapy is increasingly used for children with high-risk neuroblastoma, a paucity of lead-lined rooms limits its wider use. We implemented radiation safety procedures to comply with New York City Department of Health and Mental Hygiene regulations for therapeutic radioisotopes and administered (131) I-MIBG using rolling lead shields. PROCEDURE: Patients received 0.67 GBq (18 mCi)/kg/dose (131) I-MIBG on an IRB-approved protocol (NCT00107289). Radiation safety procedures included private room with installation of rolling lead shields to maintain area dose rates ≤0.02 mSv/hr outside the room, patient isolation until dose rate <0.07 mSv/hr at 1 m, and retention of a urinary catheter with collection of urine in lead boxes. Parents were permitted in the patient's room behind lead shields, trained in radiation safety principles, and given real-time radiation monitors. RESULTS: Records on 16 (131) I-MIBG infusions among 10 patients (age 2-11 years) were reviewed. Mean ± standard deviation (131) I-MIBG administered was 17.67 ± 11.14 (range: 6.11-40.59) GBq. Mean maximum dose rates outside treatment rooms were 0.013 ± 0.008 mSv/hr. Median time-to-discharge was 3 days post-(131) I-MIBG. Exposure of medical staff and parents was below regulatory limits. Cumulative whole-body dose received by the physician, nurse, and radiation safety officer during treatment was 0.098 ± 0.058, 0.056 ± 0.045, 0.055 ± 0.050 mSv, respectively. Cumulative exposure to parents was 0.978 ± 0.579 mSv. Estimated annual radiation exposure for inpatient nurses was 0.096 ± 0.034 mSv/nurse. Thyroid bioassay scans on all medical personnel showed less than detectable activity. Contamination surveys were <200 dpm/100 cm(2) . CONCLUSIONS: The use of rolling lead shields and implementation of specific radiation safety procedures allows administration of high-dose (131) I-MIBG and may broaden its use without dedicated lead-lined rooms.

Acute pain relief after Mantram meditation in children with neuroblastoma undergoing anti-GD2 monoclonal antibody therapy.

Nonpharmacologic, mind-body interventions are used to reduce anxiety in pediatric patients. Anti-ganglioside GD2 monoclonal antibody (anti-GD2 MoAb 3F8) therapy is the standard of care for high-risk neuroblastoma and pain is its major side effect. We performed a retrospective analysis of children undergoing anti-GD2 MoAb 3F8 treatment who received guided meditation. Meditation involved concentrating on the repetition of rhythmic, melodic sounds purported to slow breathing and induce a relaxation response. A total of 71% patients completed a session at first (n=19) or second attempt (n=5). Patients received fewer analgesic doses to manage anti-GD2 MoAb 3F8-induced pain when participating in meditation (n=17, mean=-0.4 dose, P<0.01). Mantram meditation is a feasible outpatient intervention associated with reduced analgesic requirements.

Single-chain Fv-streptavidin substantially improved therapeutic index in multistep targeting directed at disialoganglioside GD2.

UNLABELLED: Multistep targeting can improve the therapeutic index of antibody-based targeting, particularly relevant to pediatric tumors where acute toxicity and late effects of treatment are major concerns. Neuroblastoma is uniquely suited for such investigations because of its abundance of surface ganglioside GD2. METHODS: 5F11scFv (scFv = single-chain variable fragment) was constructed from the variable regions of the heavy (V(H)) and kappa-light (V(L)) chain complementary DNA (cDNA) of anti-GD2 IgM hybridoma 5F11 and ligated to full-length streptavidin cDNA for expression in Escherichia coli. Purified 5F11-scFv-streptavidin (5F11-scFv-SA) was a homotetramer and showed comparable avidity to 5F11 IgM and a 30-fold improvement over monomeric scFv. Biodistribution of 5F11-scFv-SA was studied in nude mice xenografted with neuroblastoma LAN-1. Twenty-four hours after intravenous injection of 300-900 microg 5F11-scFv-SA, 150-450 microg of a thiogalactoside-containing clearing agent, (Gal-NAc)(16)-alpha-S-C(5)H(10)-NH-LC-N-Me-biotin (molecular weight, 8652), were administered intravenously, followed by approximately 2.5 microg (1.85-3.7 MBq) (111)In-1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid-biotin ((111)In-DOTA-biotin) intravenously 4 h later and clocked as time 0. RESULTS: Tumor uptake (percentage of injected dose per gram [%ID/g]) at 2 h was 7 %ID/g and decayed with a half-life of 72 h, whereas blood %ID/g rapidly decreased to <1/500 of that of tumor after the first 24 h. The tumor-to-nontumor (T/NT) ratio at 72 h was high (median, 106; range, 3.4 [kidney] to 1660 [blood]). When the area under the radioactivity curve was computed, the T/NT organ ratio was favorable (4.8 for kidney and 162 for blood). When human and murine tumors were surveyed, the T/NT ratio of (111)In-DOTA-biotin uptake correlated with their levels of GD2 expression as assayed by flow cytometry. Biotinylated polypeptides (bovine serum albumin and vasointestinal peptides) achieved selective tumor targeting when the multistep strategy was applied. CONCLUSION: Improvement in the T/NT ratio using pretargeting strategy may increase the efficacy and safety of scFv-based approaches in cancer therapy. Additionally, since biotinylated polypeptides can be rendered tumor selective, a large repertoire of agents can potentially be explored.

Neuroblastoma in adolescents and adults: the Memorial Sloan-Kettering experience.

BACKGROUND: We reviewed the utility of different treatment modalities in a large series of adolescents/adults with neuroblastoma (NB). PROCEDURE: The 30 adolescents/adults (median age, 19 years) had stage 2B (n = 1), 3 (n = 2), or 4 (n = 27) NB. Treatments included conventional and myeloablative therapy; local radiotherapy (RT); immunotherapy with anti-G(D2) 3F8 monoclonal antibody +/- granulocyte-macrophage colony-stimulating factor (GM-CSF); and 3F8 alternating with low-dose oral etoposide. RESULTS: Seven patients are in first (n = 4) or second (n = 3) complete/very good partial remission (CR/VGPR) at 9+ to 181+ (median, 45+) months. Among 13 newly diagnosed or minimally prior-treated patients, no major responses were seen in 4/4 treated with N4/N5 chemotherapy, but 6/9 treated with the higher dose N6/N7 regimens and surgery had major responses, and immunotherapy produced CR in BM in three patients. Among 17 patients referred because of resistant NB, favorable responses occurred in 6/12 treated with high-dose cyclophosphamide-based salvage therapy, including one patient who is in CR 170+ months after myeloablative consolidation and five patients who achieved CR/VGPR after 3F8/GM-CSF (n = 4) or 3F8/oral etoposide (n = 1). With a median follow-up of 32+ months post-RT, no local relapses occurred in 10/10 patients who received hyperfractionated 21 Gy RT to prevent regrowth of soft tissue masses that had been resected. CONCLUSIONS: High-dose chemotherapy and surgery can achieve a minimal disease state in >50% of newly diagnosed older NB patients. In that setting, local RT, and the use of agents with recently confirmed anti-NB activity, including anti-G(D2) antibodies, and cis-retinoic acid, may improve the poor prognosis of these patients reported to date.