Clinical or Sub-Clinical Pancreatitis (PA) Associated with Nilotinib (Nb) As Frontline for Chronic Myelogenous Leukemia (CML)

Abstract Abstract 4443 Background: Nilotinib is now standard therapy in chronic phase (CP) CML, both as initial therapy and after imatinib failure. One of the adverse effects of nilotinib is the increase in serum amylase and/or lipase levels with or without clinical pancreatitis.The mechanism by which nilotinib increases serum pancreatic enzymes is not clear. Nilotinib is able to inhibit the non-receptor tyrosine kinase c-abl with high affinity. It is possible that c-abl inhibition might interfere with the molecular mechanisms regulating pancreatic cell death, inducing pancreatic damage. Nilotinib may release calcium from the intracellular acinar stores which regulate exocrine pancreatic secretion, or it may promote the accumulation of fatty acid inside the pancreatic acinar cells which disturbs exocytose. (JOP. J Pancreas (Online) 2010 May 5; 291–293). Purpose: To understand the frequency, risk factors and management strategy for patients who develop pancreatitis (clinical or subclinical) during nilotininb frontline therapy for CML. Method: We reviewed the records of 105 CML patients treated at our institution on a clinical trial from 7/2005 to 7/2011 with nilotinib 400 mg twice daily as initial therapy for CML in chronic phase. Results: The median age for the total population was 52 yrs (range, 17 to 89), and 63 were males (60%). Thirteen (12%) pts experienced pancreatitis at least once, most frequently asymptomatic (ie, grade 1). Pancreatitis episodes occurred 28 times (2 episodes were grade 3, 2 episodes were grade 4, 10 episodes were grade 2, and 14 episodes were grade 1). Thirteen episodes (47%) occurred at a dose of 200 mg daily, 4 (14%) at 400 mg daily, and 11 (39%) at 800 mg daily. In 3 instances total bilirubin was also elevated (2 grade 2 and 1 grade 4). One patient experienced recurrent elevations (16 episodes) of lipase and amylase despite dose reduction to 200mg once daily. Concurrent use of hydrochlorothiazide and moderate alcoholic intake were identified as risk factors associated with pancreatitis in the patient who experienced recurrent episodes. Diabetes was identified as a risk factor for pancreatitis in other 4 pts. Twenty four episodes (86%) were characterized by an elevation of lipase and amylase without any clinical symptoms. In four instances, patients experienced a moderate abdominal pain without other symptoms of pancreatitis. In 3 instances, imaging (ultrasound and/or CT scan) demonstrated normal pancreases. Management of pancreatitis included transient nilotinib interruption in most instances. In most patients, lipase and amylase values returned to normal within 14 days of stopping nilotinib. Three patients eventually required change from nilotinib to other tyrosine kinase inhibitors (TKI) (imatinib 2, dasatinib 1) without recurrence of pancreatitis. One of these pts switched to imatinib because of recurrent pancreatitis and the other 2 were switched because of nilotinib toxicities (liver and cardiac toxicity). At the time of pancreatitis episodes, 54% had achieved complete cytogenetic response (CCyR), and 8% complete molecular response (CMR). Rates of (CCyR) were 92% and 94% in patients who experienced and who did not experience pancreatitis, respectively. Rates of major molecular response (MMR) were 100%and 87% in patients who experienced and who did not experience pancreatitis, respectively. Rates of complete hematologic response (CHR) were 100% and 98% in patients who experienced and who did not experience pancreatitis, respectively. The 3-year event-free survival (EFS), treatment- free survival (TFS), and overall survival (OS) rates were 100% in patients who experienced and 93%, 97%, and 100% in patients who did not experience pancreatitis, respectively. Conclusion: Pancreatitis associated with nilotinib is most frequently grade 1 and 2 (asymptomatic enzyme elevation). Close monitoring and timely intervention may allow patients to continue therapy and achieve the desired clinical benefit. Rarely, pancreatitis may require treatment discontinuation. Disclosures: Cortes: BMS: Consultancy, Research Funding; Novartis: Consultancy, Research Funding; Ariad: Consultancy, Research Funding; Pfizer: Consultancy, Research Funding; Deciphera: Research Funding.