Browsing by Author "Plotkin, Scott R."

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    Brigatinib causes tumor shrinkage in both NF2-deficient meningioma and schwannoma through inhibition of multiple tyrosine kinases but not ALK
    (PLOS, 2021-07-15) Chang, Long-Sheng; Oblinger, Janet L.; Smith, Abbi E.; Ferrer, Marc; Angus, Steven P.; Hawley, Eric; Petrilli, Alejandra M.; Beauchamp, Roberta L.; Riecken, Lars Björn; Erdin, Serkan; Poi, Ming; Huang, Jie; Bessler, Waylan K.; Zhang, Xiaohu; Guha, Rajarshi; Thomas, Craig; Burns, Sarah S.; Gilbert, Thomas S.K.; Jiang, Li; Li, Xiaohong; Lu, Qingbo; Yuan, Jin; He, Yongzheng; Dixon, Shelley A.H.; Masters, Andrea; Jones, David R.; Yates, Charles W.; Haggarty, Stephen J.; La Rosa, Salvatore; Welling, D. Bradley; Stemmer-Rachamimov, Anat O.; Plotkin, Scott R.; Gusella, James F.; Guinney, Justin; Morrison, Helen; Ramesh, Vijaya; Fernandez-Valle, Cristina; Johnson, Gary L.; Blakeley, Jaishri O.; Clapp, D. Wade; Pediatrics, School of Medicine
    Neurofibromatosis Type 2 (NF2) is an autosomal dominant genetic syndrome caused by mutations in the NF2 tumor suppressor gene resulting in multiple schwannomas and meningiomas. There are no FDA approved therapies for these tumors and their relentless progression results in high rates of morbidity and mortality. Through a combination of high throughput screens, preclinical in vivo modeling, and evaluation of the kinome en masse, we identified actionable drug targets and efficacious experimental therapeutics for the treatment of NF2 related schwannomas and meningiomas. These efforts identified brigatinib (ALUNBRIG®), an FDA-approved inhibitor of multiple tyrosine kinases including ALK, to be a potent inhibitor of tumor growth in established NF2 deficient xenograft meningiomas and a genetically engineered murine model of spontaneous NF2 schwannomas. Surprisingly, neither meningioma nor schwannoma cells express ALK. Instead, we demonstrate that brigatinib inhibited multiple tyrosine kinases, including EphA2, Fer and focal adhesion kinase 1 (FAK1). These data demonstrate the power of the de novo unbiased approach for drug discovery and represents a major step forward in the advancement of therapeutics for the treatment of NF2 related malignancies.
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    Cabozantinib for neurofibromatosis type 1-related plexiform neurofibromas: a phase 2 trial
    (Springer Nature, 2021-01) Fisher, Michael J.; Shih, Chie-Schin; Rhodes, Steven D.; Armstrong, Amy E.; Wolters, Pamela L.; Dombi, Eva; Zhang, Chi; Angus, Steven P.; Johnson, Gary L.; Packer, Roger J.; Allen, Jeffrey C.; Ullrich, Nicole J.; Goldman, Stewart; Gutmann, David H.; Plotkin, Scott R.; Rosser, Tena; Robertson, Kent A.; Widemann, Brigitte C.; Smith, Abbi E.; Bessler, Waylan K.; He, Yongzheng; Park, Su-Jung; Mund, Julie A.; Jiang, Li; Bijangi-Vishehsaraei, Khadijeh; Robinson, Coretta Thomas; Cutter, Gary R.; Korf, Bruce R.; Blakeley, Jaishri O.; Clapp, D. Wade; Pediatrics, School of Medicine
    Neurofibromatosis type 1 (NF1) plexiform neurofibromas (PNs) are progressive, multicellular neoplasms that cause morbidity and may transform to sarcoma. Treatment of Nf1fl/fl;Postn-Cre mice with cabozantinib, an inhibitor of multiple tyrosine kinases, caused a reduction in PN size and number and differential modulation of kinases in cell lineages that drive PN growth. Based on these findings, the Neurofibromatosis Clinical Trials Consortium conducted a phase II, open-label, nonrandomized Simon two-stage study to assess the safety, efficacy and biologic activity of cabozantinib in patients ≥16 years of age with NF1 and progressive or symptomatic, inoperable PN ( NCT02101736 ). The trial met its primary outcome, defined as ≥25% of patients achieving a partial response (PR, defined as ≥20% reduction in target lesion volume as assessed by magnetic resonance imaging (MRI)) after 12 cycles of therapy. Secondary outcomes included adverse events (AEs), patient-reported outcomes (PROs) assessing pain and quality of life (QOL), pharmacokinetics (PK) and the levels of circulating endothelial cells and cytokines. Eight of 19 evaluable (42%) trial participants achieved a PR. The median change in tumor volume was 15.2% (range, +2.2% to -36.9%), and no patients had disease progression while on treatment. Nine patients required dose reduction or discontinuation of therapy due to AEs; common AEs included gastrointestinal toxicity, hypothyroidism, fatigue and palmar plantar erythrodysesthesia. A total of 11 grade 3 AEs occurred in eight patients. Patients with PR had a significant reduction in tumor pain intensity and pain interference in daily life but no change in global QOL scores. These data indicate that cabozantinib is active in NF1-associated PN, resulting in tumor volume reduction and pain improvement.
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    Sleep and pulmonary outcomes for clinical trials of airway plexiform neurofibromas in NF1
    (AAN, 2016-08) Plotkin, Scott R.; Davis, Stephanie D.; Robertson, Kent A.; Akshintala, Srivandana; Allen, Julian; Fisher, Michael J.; Blakely, Jaishri O.; Widemann, Brigitte C.; Ferner, Rosalie E.; Marcus, Carole L.; Department of Pediatrics, School of Medicine
    Objective: Plexiform neurofibromas (PNs) are complex, benign nerve sheath tumors that occur in approximately 25%–50% of individuals with neurofibromatosis type 1 (NF1). PNs that cause airway compromise or pulmonary dysfunction are uncommon but clinically important. Because improvement in sleep quality or airway function represents direct clinical benefit, measures of sleep and pulmonary function may be more meaningful than tumor size as endpoints in therapeutic clinical trials targeting airway PN. Methods: The Response Evaluation in Neurofibromatosis and Schwannomatosis functional outcomes group reviewed currently available endpoints for sleep and pulmonary outcomes and developed consensus recommendations for response evaluation in NF clinical trials. Results: For patients with airway PNs, polysomnography, impulse oscillometry, and spirometry should be performed to identify abnormal function that will be targeted by the agent under clinical investigation. The functional group endorsed the use of the apnea hypopnea index (AHI) as the primary sleep endpoint, and pulmonary resistance at 10 Hz (R10) or forced expiratory volume in 1 or 0.75 seconds (FEV1 or FEV0.75) as primary pulmonary endpoints. The group defined minimum changes in AHI, R10, and FEV1 or FEV0.75 for response criteria. Secondary sleep outcomes include desaturation and hypercapnia during sleep and arousal index. Secondary pulmonary outcomes include pulmonary resistance and reactance measurements at 5, 10, and 20 Hz; forced vital capacity; peak expiratory flow; and forced expiratory flows. Conclusions: These recommended sleep and pulmonary evaluations are intended to provide researchers with a standardized set of clinically meaningful endpoints for response evaluation in trials of NF1-related airway PNs.