Case series of MET exon 14 skipping mutation-positive non-small-cell lung cancers with response to crizotinib and cabozantinib.

The mesenchymal-to-epithelial transition (MET) gene is altered and becomes a driver mutation in up to 5% of non-small-cell lung cancer (NSCLC). We report our institutional experience treating patients with MET exon 14 skipping (METex14) mutations, including responses to the MET inhibitors crizotinib and cabozantinib. We identified cases of NSCLC with METex14 mutations using an institutionally developed or commercial next-generation sequencing assay. We assessed patient and disease characteristics by retrospective chart review. Some patients were treated off-label by the physician with crizotinib or cabozantinib, and tumor responses to these agents were assessed. A total of 15 patients with METex14-mutated NSCLC were identified, predominantly male (n=10) with a smoking history (60%) and a median age of 74.0 years. No other actionable somatic mutations were detected. Stage distribution included 26.7% stage I, 6.7% stage II, 6.7% stage III, and 60.0% stage IV. Among patients treated with crizotinib or cabozantinib (n=6), three patients showed partial response and one patient showed stable disease on the basis of RECIST criteria. Four patients experienced side effects requiring drug holiday, reduction, or cessation. Our findings highlight the diversity in presentation and histology of NSCLC with METex14 mutations, which were found in the absence of other actionable driver mutations. We observed evidence of tumor response to crizotinib and cabozantinib, supporting the previous reports that METex14 mutations in NSCLC are actionable driver events.

Nelarabine neurotoxicity with concurrent intrathecal chemotherapy: Case report and review of literature.

Severe nelarabine neurotoxicity in a patient who received concurrent intrathecal (IT) chemotherapy is reported. A 37-year-old Caucasian woman with a history of T-cell lymphoblastic lymphoma was admitted for relapsed disease. She was originally treated with induction chemotherapy followed by an autologous transplant. She developed relapsed disease 10 months later with leukemic involvement. She was re-induced with nelarabine 1500 mg/m(2) on days 1, 3, and 5 with 1 dose of IT cytarabine 100 mg on day 2 as central nervous system (CNS) prophylaxis. At the time of treatment, she was on continuous renal replacement therapy due to sequelae of tumor lysis syndrome (TLS). She tolerated therapy well, entered a complete remission, and recovered her renal function. She received a second cycle of nelarabine without additional IT prophylaxis one month later. A week after this second cycle, she noted numbness in her lower extremities. Predominantly sensory, though also motor and autonomic, peripheral neuropathy started in her feet, ascended proximally to the mid-thoracic region, and eventually included her distal upper extremities. A magnetic resonance imaging (MRI) of her spine demonstrated changes from C2 to C6 consistent with subacute combined degeneration. Nelarabine was felt to be the cause of her symptoms. Her neuropathy stabilized and showed slight improvement and ultimately received an unrelated, reduced-intensity allogeneic transplant while in complete remission, but relapsed disease 10 weeks later. She is currently being treated with best supportive care. To our knowledge, this is the first published case report of severe neurotoxicity caused by nelarabine in a patient who received concurrent IT chemotherapy.