ASH Clinical News August 2016 | Page 30

On Location Conference Coverage Masitinib Improves Symptom Burden, Responses in Patients with Severe Systemic Mastocytosis and asthenia (4.1%). The most frequent serious AEs in the masitinib arm were diarrhea (4.3%) and urticaria (2.9%). “Data from the study’s extension period showed that masitinib was capable of maintaining remission of symptoms for over two years,” Dr. Hermine noted. “This is an important observation given that ISM and SSM are life-long conditions requiring chronic management.” skin events and typically manageable with dose reductions. Masitinib, a selective oral tyrosine kinase inhibitor (TKI) targeting wild-type KIT, LYN, and FYN, reduced the severity of a Long-term safety assessment revealed comparable rates of diverse range of symptoms in patients with severely symptom- AEs between both treatment arms, with no deaths or lifeREFERENCE Hermine O, Chandesris MO, Livideanu CB, et al. Masitinib for the treatment of severely sympthreatening AEs in the masitinib arm. atic indolent or smoldering systemic mastocytosis (ISM or tomatic indolent and smoldering systemic mastocytosis: a randomized, placebo-controlled, Severe AEs with a greater than four percent difference SSM) who were unresponsive to other treatments, according international, phase 3 study. Abstract S828. Presented at the EHA 21st Congress, June 10, 2016; between treatment arms were: diarrhea (9.8%), rash (5.7%), Copenhagen, Denmark. to results from a randomized phase III S:6.75” trial presented by Olivier Hermine, MD, PhD, from the University of Paris Descartes, at the European Hematology Association’s 21st Congress. BOSULIF is indicated for the treatment of adult patients with chronic, accelerated, or blast phase Philadelphia Mastocytosis is designated as an orchromosome–positive (Ph+) chronic myelogenous leukemia (CML) with resistance or intolerance to prior therapy. phan disease by the U.S. Food and Drug Administration and is characterized by an abnormal proliferation or activation In the treatment of adult patients with Ph+ CML with resistance or intolerance to prior therapy of mast cells either in the skin or in bone marrow or other organs. Masitinib is the first drug to be evaluated in phase III in the indolent form of mastocytosis – regardless of severity, Dr. Hermine noted. “There is currently no registered or established standard treatment for this rare condition with a high unmet medical need,” he said in a press release. “Masitinib may be an important new ( b o s u t inib) treatment option for these patients … with both efficacy and safety data indicating a possibility for effective longterm management of this difficult-totreat condition.” All 135 patients enrolled in the trial had severely symptomatic ISM or SSM (defined as at least one of the following baseline symptoms: pruritus score ≥9, ≥8 flushes per week, Hamilton rating scale for depression score ≥19, or Fatigue Impact Scale [FIS] score ≥75). Patients received masitinib 6 mg/kg daily over 24 weeks (with a possible extension period) and were followed from Bosutinib (BOSULIF®) is recommended by the NCCN Clinical Practice Guidelines in eight weeks to 96 weeks post-treatment Oncology (NCCN Guidelines®) as a treatment option for patients with CML in need initiation. of 2nd- or later-line TKI therapy.1 Masitinib resulted in a significant improvement over placebo in rates of cumulative response (the study’s Study design: BOSULIF 500 mg once-daily treatment was studied in a single-arm, Phase 1/2, open-label, multicenter primary endpoint; defined as a ≥75% trial (N=546) in patients with CP, AP, or BP CML in second line (after imatinib) or in third line (after imatinib followed by improvement in at least one severe basedasatinib and/or nilotinib). Of the 546 patients enrolled, 73% were imatinib resistant and 27% were imatinib intolerant.2 line symptom): 18.7 percent versus 7.4 AP=accelerated phase; BP=blast phase; CP=chronic phase. percent, respectively (odds ratio [OR] = 3.6 (95% CI 1.2-10.8; p=0.008). Response was confirmed in sensitivity and secondary analyses, Dr. Hermine reported. For example, at week 24, masihepatic enzyme tests monthly for the first 3 months and as clinically indicated. IMPORTANT SAFETY INFORMATION tinib-treated patients had lower tryptase In patients with transaminase elevations, monitor liver enzymes more Contraindication: History of hypersensitivity to BOSULIF. Reactions have levels relative to baseline, compared frequently. Drug-induced liver injury has occurred. Withhold, dose reduce, or included anaphylaxis. Anaphylactic shock occurred in less than 0.2% of treated with patients who received placebo: discontinue BOSULIF as necessary. In patients with mild, moderate, or severe patients in clinical trials. 18.0 percent decrease in the masitinib hepatic impairment, the recommended starting dose is 200 mg daily. arm versus a 2.2 percent increase in the Gastrointestinal Toxicity: Diarrhea, nausea, vomiting, and abdominal pain Renal Toxicity: An on-treatment decline in estimated glomerular filtration placebo arm (p<0.001). can occur. In the clinical trial, median time to onset for diarrhea was 2 days, rate h as occurred in patients treated with BOSULIF. Monitor renal function Masitinib also led to significantly median duration was 1 day, and median number of episodes per patient was 3 at baseline and during therapy, with particular attention to patients with better clearance of urticaria pigmentosa (range 1-221). Monitor and manage patients using standards of care, including preexisting renal impairment or risk factors. Consider dose adjustment in patients who received the study drug antidiarrheals, antiemetics, and/or fluid replacement. Withhold, dose reduce, in patients with baseline and treatment emergent renal impairment. The compared with placebo (p=0.02). or discontinue BOSULIF as necessary. recommended starting doses for patients with severe renal impairment Treatment with masitinib appeared Myelosuppression: Thrombocytopenia, anemia, and neutropenia can occur. (CrCL <30 mL/min) or moderate renal impairment (CrCL 30-50 mL/min) safe and consistent with the drug’s Perform complete blood counts weekly for the first month and then monthly are 300 mg and 400 mg daily, respectively. known adverse events (AEs); toxicities or as clinically indicated. Withhold, dose reduce, or discontinue BOSULIF were predominantly gastrointestinal or Fluid Retention: Fluid retention can occur and may cause pericardial effusion, Everyone has a distinct profile Consider your patient.Consider BOSULIF. as necessary. Hepatic Toxicity: Twenty percent of patients experienced an increase in either ALT or AST. Liver enzyme elevation usually occurs early in treatment. Perform 28 ASH Clinical News pleural effusion, pulmonary edema, and/or peripheral edema. Monitor and manage patients using standards of care. Interrupt, dose reduce, or discontinue BOSULIF as necessary. B:15.5” T:15.25” G:.5”