Patterns Of Non-Hematological Adverse Effects In Patients With Chronic Myeloid Leukemia In Chronic Phase (CML-CP) Treated With Ponatinib – Experience At a Single Institution

Ponatinib is a multi-targeted tyrosine kinase inhibitor (TKI) efficacious in pts with refractory CML. Ponatinib inhibits other tyrosine kinases (e.g. RET, FGFR, FLT3) that may lead to off target adverse effects (AE). We report a single-institution experience of frequencies of non-hematological AE among pts on therapy with ponatinib.

A total of 90 pts with CML-CP[49 relapsed refractory (RR), 41 frontline] treated at our institution on clinical trials with ponatinib were analyzed. AE were recorded on each pt visit and charts were reviewed for AE and risk factors.

For RR pts (n=49)the starting dose of ponatinib was 45 mg in 42 (86%) pts. 39 (80%) had dose interruptions, due in 17 (44%) to grade 3 thrombocytopenia and in 22 (56%) to non-hematological AE (elevated pancreatic enzymes 7 pts of whom 5 had pancreatitis; body aches and headache 7; hypertension 7; skin toxicity 5; fatigue 5). 35 pts (71%) had dose reduction to 30 or 15 mg. Hypertension (H.T.) stage 2 (≥160/100 mm Hg) occurred in 15 (31%) pts; only 2 of new onset. Blood pressure was controlled in all with antihypertensives. Other cardiovascular AE included QTc prolongation in 1 pt, atrial fibrillation in 1 pt, acute myocardial infarction in 3, venous thrombosis in 3, arterial thrombosis in 4, transient ischemic attack (TIA) in 1 and Raynaud’s in 1. No pt discontinued ponatinib due to cardiovascular AE’s. Symptomatic pancreatitis developed in 8 pts (16%). Grade 3/4 elevations in serum lipase and amylase occurred in 12 (24%) pts and 2 (4%) pts respectively. Median days to onset of pancreatitis was 24 (range 7-456). 27 pts (55%) developed cutaneous toxicity including xerosis/dry skin in 10 (37%) and grade 3 erythroderma and exfoliation of the skin in 5. Four pts died, none related to ponatinib. 13 pts went off the study: 5 went to SCT, 3 progressed, 1 pt died in CCyR of multiple co-morbidities, 1 pt had progressive melanoma, 1 pt was transferred to another hospital, and 2 for ponatinib-related AE (headache in 1 and headache, fatigue, depression, and abdominal pain in 1).

For pts in frontline setting (n=41) the starting dose was 45 mg in all. 29 pts (71%) had dose interruptions due to one or more of the following: grade 3/4 pancreatic enzyme elevation in 16, myelosuppression in 4, and various non-hematological AE in 15 (skin toxicity in 4, fatigue in 2, headache in 1, chest pain in 2, elevated liver enzymes in 2, suspected seizure vs. TIA in 1, grade 3 diarrhea in 1, memory disturbances in 1, and grade 3 hypertension in 1, erectile dysfunction in 1). 24 pts (59%) had dose reduction, from 45 mg to 30 mg in 20 pts and then to 15 mg in 4 pts. H.T. stage 2 occurred in 3 (7%) pts usually among patients with pre-existing H.T. Other cardiovascular AE included grade 2 QTc prolongation in 1 pt, possible TIA vs. possible seizure in 1, and Raynaud’s in 2. Pancreatitis was seen in 12 pts (29%) with grade 1-2 and 6 pts (15%) with grade 3/4. Grade 3/4 lipase/amylase elevations occurred in 16 (39%) and 3 (7%) pts. Median days to the onset of pancreatitis were 6 (4-22). 34 pts (83%) developed skin toxicity with rash (any grade) in 25 pts (61%), xerosis/dry skin in 18 pts (44%) and grade 3 erythroderma and skin exfoliation in 2 (pts may have had ≥1 type of skin AE). 2 pts discontinued therapy, due to severe xerosis in 1 and recurrent gra 4 neutropenia in another. 1 pt developed grade 2 pericarditis possibly related to ponatinib. For all the 90 pts, risk factors for cardiovascular and pancreatic toxicities included 20 (22%) smokers, 2 heavy alcohol consumers, 27 (30%) obese (BMI ≥30 Kg/m2), 30 (33%) with hypertriglyceridemia, 17 (19%) had hypercholesterolemia and 10 pts were receiving lipid lowering therapies.

Ponatinib is generally well tolerated and AEs can usually be properly managed. AE are more common in RR pts with greater frequency of hypertension, cardiovascular complications, headache, dry mouth and dose interruptions. Most pts are able to continue therapy after dose adjustments.

Kantarjian:ARIAD: Research Funding. Cortes:Ariad, Pfizer, Teva: Consultancy; Ariad, BMS, Novartis, Pfizer, Teva: Research Funding.