Status and phase
Conditions
Treatments
About
Atypical teratoid/rhabdoid tumors (AT/RTs) account for 1%-2% of all central nervous system (CNS) tumors in children aged 0-14 years, yet are among the most common malignant CNS tumors in infants less than 1 year old. AT/RTs are defined by the loss of INI1 or, rarely, BRG1, encoded by the SMARCB1 and SMARCA4 genes, respectively. Patients with AT/RTs have dismal outcomes due to their highly malignant nature and young age at diagnosis. There remains no standard therapy for AT/RTs. Multimodal treatment strategies include a selective combination of conventional chemotherapy, high dose chemotherapy and stem cell rescue, intrathecal chemotherapy, and radiotherapy after tumor resection. The survival rate, even with aggressive treatment, is still low (2-year survival rate is 32.6%-44.6%). Moreover, currently used cytotoxic therapies incur some neurocognitive side effects, particularly in infants, highlighting the urgent need for novel targeted therapies.
Bortezomib (Velcade®) is the first generation proteasome inhibitor developed by Millennium Pharmaceuticals, Inc. as an anti-cancer medication. Bortezomib was approved by FDA for the treatment of adult patients with multiple myeloma and mantle cell lymphoma (newly diagnosed or relapse/recurrent disease). In children, the safety of BTZ has been proved in phase I clinical trial of patients with acute lymphoblastic leukemia, refractory or recurrent solid tumors, relapsed/refractory high-risk neuroblastoma. Recently, we found the proteasome-encoding genes were highly expressed in AT/RTs compared with that in normal brain tissues, correlated with the malignant phenotype of tumor cells, and were essential for tumor cell survival. Bortezomib targets proteostasis, inhibiting tumor growth and inducing apoptosis through p53 accumulation in three Myc-AT/RT cell lines and in mice with orthotopic xenografts of AT/RT. Our findings suggest that BTZ is a promising targeted therapy for Myc-AT/RTs (manuscript under review). To determine whether the other subgroups of ATRTs (i.e., SHH and TYR subgroups) are sensitive to BTZ, we conducted the in vivo drug test in 2 SHH-AT/RT cell lines (CHLA-02 and CHLA-04). Although CHLA-02 and CHLA-04 cell line were less sensitive to BTZ (IC50 of 15.1 (14.3-15.9) nM and 15.8 (14.5-17.3) nM, respectively) than Myc-AT/RT cell line (IC50 of 5.84 to 8.7 nM), these inhibitory concentrations are still clinically achievable (Cmax, 231.6-312.3 nM). Furthermore, the dependence on ubiquitin proteasome system for survival and high sensitivity to proteasome inhibitors have been reported in SMARCB1-deficient cancer cells. Additionally, we also observed the subgroup shifting in one infant with AT/RTs, from SHH subgroup of primary tumor to Tyr subgroup of the first recurrent tumor and Myc subgroup of the second recurrent tumor. Therefore, we hypothesize that BTZ treatment is potentially effective to all subgroups of CNS AT/RT and propose a clinical trial utilizing BTZ as an add-on therapy to standard and high-dose chemotherapy
Enrollment
Sex
Ages
Volunteers
Inclusion criteria
Patients with a valid Informed Consent Form signed by the Legal Guardian and/or Patient himself/herself.
Patients with CNS AT/RT who were initially diagnosed at the age of 0-20 years.
Disease Status:
Cohort 1: Patients with newly diagnosed AT/RT; Cohort 2: Patients with recurrent or refractory CNS AT/RT who have had at least 1 line of chemotherapy with radiographically measurable disease as defined by at least 1 lesion that can be measured in 2 dimensions.
Previous Anticancer Therapy:
Cohort 1: No previous anticancer chemotherapy other than the use of corticosteroids.
Cohort 2: Patient has fully recovered from the acute toxic effects of chemotherapy, immunotherapy, or radiation therapy prior to entering this study:
Patients must have adequate organ and marrow function as defined below at enrollment and on day 1 of (or within 1 week prior to) each cycle:
LV Ejection Fraction of ≥ 50% by Echocardiogram
Patient must have the Performance status defined by Lansky (< 16 years of age) or Karnofsky (≥16 years of age) Performace Status of ≥ 30 (Cohort 1) or ≥ 60 (Cohort 2).
Patients who are unable to walk because of paralysis, but who are up in a wheelchair, will be considered to be ambulatory for the purpose of assessing the performance score.
Female patients who are at least 10-years-old or are post-menarchal must have a negative serum or urine pregnancy test prior to enrollment
Fertile patients must use effective contraception
Life expectancy > 8 weeks
No evidence of dyspnea at rest
Fertile patients must use effective contraception
Exclusion criteria
Primary purpose
Allocation
Interventional model
Masking
6 participants in 1 patient group
Loading...
Data sourced from clinicaltrials.gov
Clinical trials
Research sites
Resources
Legal