A significant biological effect of panobinostat, measured by acetylation status of histone H3 and H4, was achieved at a dose of 15 mg/m. PK data and drug tolerability at 15 mg/m was similar to that previously published.
BACKGROUND
Panobinostat treatment has been shown to terminally differentiate malignant rhabdoid tumor (MRT)/atypical teratoid rhabdoid tumors (ATRT) in pre-clinical models. This is an open label, phase II study of panobinostat in patients with newly diagnosed or relapsed MRT/ATRT. AIMS: To assess the anti-tumor activity of low dose, continuous panobinostat, its associated toxicities, the biological activity of low dose panobinostat by measuring histone acetylation status in peripheral mononuclear cells (PMNC), and markers of differentiation in fresh tumor tissue specimens.
METHODS
Following cycles of induction and consolidation chemotherapy and/or radiation treatment, patients were enrolled and commenced on panobinostat as a continuous daily oral dose starting at 10mg/m2 following a three-week wash out period between therapies. Real-time acetylation status, measuring acetylated H4 on PMNC, was performed to determine the pharmacodynamics of panobinostat. Patients were monitored for drug toxicities with the possibility of dose reductions in decrements of 2mg/m2.
RESULTS
Six patients with newly diagnosed ATRT/MRT and one patient with relapsed MRT have been enrolled to date. The average age at enrollment was 2.5 years. Currently, six patients (85.7%) remain on study with a mean treatment duration of 170 days (range 44–327 days). One patient was removed from study at day 44 due to disease progression. The main dose-limiting toxicity observed to date has been myelosuppression. Panobinostat, at a dose of 10mg/m2, caused significant acetylation of H4 in PMNC.
CONCLUSIONS
Treatment with panobinostat appears to be well tolerated in infants with MRT/ATRT, with successful real-time pharmacodynamic assessment of H4 acetylation.
BACKGROUND: Panobinostat treatment has been shown to terminally differentiate malignant rhabdoid tumours (MRT) and atypical teratoid rhabdoid tumours (ATRT) in pre-clinical models. We report results of the open label, phase II study of oral panobinostat in patients with newly diagnosed or relapsed MRT/ATRT. AIMS: To assess the anti-tumour activity of low dose, continuous oral panobinostat as well as its associated toxicities. To assess the biological activity of low dose panobinostat by measuring histone H4 acetylation status in peripheral mononuclear cells (PMNC), and differentiation markers. METHODS: Following primary institutional standard of care induction and consolidation chemotherapy and/or radiation treatment, patients were enrolled and commenced on panobinostat as a continuous daily oral dose starting at 10mg/m2/day, with a three-week wash out period between therapies. Real-time acetylation status, measuring acetylated H4 on PMNC, was performed to determine the pharmacodynamics of panobinostat at different dosing levels. Patients were monitored for toxicity; dose reductions were in decrements of 2mg/m2/day. RESULTS: A total of 13 patients with newly diagnosed ATRT/MRT and one patient with relapsed MRT have been enrolled. The average age at enrollment was 3.6 years (range 0.8-6.8 years). The mean treatment duration was 206 days (13-344 days). Currently, six patients (42.9%) remain on study with a mean study duration of 531 days (range 13-895 days). 6/14 patients (42.9%) were removed due to disease progression at a mean study duration of 245 days (44-560 days). 2/14 patients (14.3%) withdrew due to toxicity. 12/14 patients (85.7%) required dose reductions. The main toxicities were thrombocytopaenia and leukopaenia (Grade III-IV). Real-time pharmacodynamic assessment of panobinostat, at a dose as low as 6mg/m2/day resulted in significant acetylation of histone H4 in PMNC. CONCLUSIONS: Treatment with low dose panobinostat is well tolerated in infants and children with MRT/ATRT, with significant acetylation of histone H4 in PMNC.
International data demonstrate association between clinical trial participation and reduced cancer mortality. Adolescents and young adults (AYA) have low clinical trial enrollment rates. We established a program to understand local barriers and develop targeted solutions that lead to greater AYA clinical trial participation. Methods: A steering committee (SC) with expertise in adult and pediatric oncology, research ethics, and consumer representation was formed. The SC mapped barriers related to AYA trial access and established working groups (WGs) around three themes. Results: The Regulatory Awareness WG identified a lack of understanding of processes that support protocol approval for clinical trials across the AYA age range. A guideline to raise awareness was developed. The Access WG identified challenges for young adults (18-25 years) to access a pediatric hospital to enroll in a pediatric trial. A procedure was developed to streamline applications for access. The first six applications using this procedure have been successful. The Availability WG identified lack of pediatric-adult oncology reciprocal relationships as a barrier to awareness of open trials, and future collaboration. An AYA Craft Group Framework was established to grow relationships within tumor streams across institutions; two craft groups are now operating locally. An additional achievement was a successful request to the Therapeutic Goods Administration
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