The natural history of vascular and other complications in patients treated with nilotinib for chronic myeloid leukemia.

Although second-generation tyrosine kinase inhibitors (TKIs) show superiority in achieving deep molecular responses in chronic myeloid leukemia in chronic phase (CML-CP) compared with imatinib, the differing adverse effect (AE) profiles need consideration when deciding the best drug for individual patients. Long-term data from randomized trials of nilotinib demonstrate an increased risk of vascular AEs (VAEs) compared with other TKIs, although the natural history of these events in response to dose modifications or cessation has not been fully characterized. We retrospectively reviewed the incidence of nilotinib-associated AEs in 220 patients with CML-CP at 17 Australian institutions. Overall, AEs of any grade were reported in 95 patients (43%) and prompted nilotinib cessation in 46 (21%). VAEs occurred in 26 patients (12%), with an incidence of 4.1 events per 100 patient-years. Multivariate analysis identified age (P = .022) and dyslipidemia (P = .007) as independent variables for their development. There was 1 fatal first VAE, whereas the remaining patients either continued nilotinib (14 patients) or stopped it immediately (11 patients). Recurrent VAEs were associated with ongoing therapy in 7 of 14 who continued (with 2 fatal VAEs) vs 1 of 11 who discontinued (P = .04). Nineteen of the 23 evaluable patients surviving a VAE ultimately stopped nilotinib, of whom 14 received an alternative TKI. Dose reduction or cessation because of VAEs did not adversely affect maintenance of major molecular response. These findings demonstrate that in contrast to other AEs, VAEs are ideally managed with nilotinib cessation because of the increased risk of additional events with its ongoing use.

High-dose palliative radiotherapy for malignant pleural mesothelioma.

INTRODUCTION: High-dose radiotherapy to the hemithorax for patients with malignant pleural mesothelioma is a controversial treatment. Between 2003 and 2013 our institution had a policy of giving hemithoracic radiotherapy to at least 45 Gy. This retrospective study reports survival, progression and toxicity associated with this policy. METHODS: Seventy-one patients with pleural mesothelioma were irradiated with doses of 45-60 Gy. Conformal radiotherapy (3D-CRT) to the lower hemithorax was used for 17 and intensity-modulated radiotherapy (IMRT) to the whole hemithorax for 54 patients. All patients have been followed up for at least 2 years from commencement of radiotherapy. RESULTS: Sixty-four patients (90%) completed planned radiotherapy and seven stopped early, usually due to progressive disease. Median overall survival was 9.5 months (95% CI: 7.7-12.4) and median progression-free survival was 4.9 months (95% CI: 4.4-5.8). Eighty-seven per cent of patients progressed or died within 2 years: 25% in-field, 49% outside the RT field and 13% died without progression. Severe toxicity (grade 3-5) was observed in 53% of 3D-CRT and 78% of IMRT patients, most commonly pulmonary fibrosis 27%, radiation dermatitis 18%, dyspnoea 11%, GGT increased 11%, pneumonitis 10%, pleuritic pain 8% and fatigue 8%. There were two, possibly three, treatment-related deaths. CONCLUSION: High-dose radiotherapy to the hemithorax caused significant toxicity to most patients with no improvement in survival. Lower doses of radiotherapy to limited volumes may be useful for palliative purposes.

The incidence and natural history of dasatinib complications in the treatment of chronic myeloid leukemia.

Dasatinib has shown superiority over imatinib in achieving molecular responses (MRs) in chronic phase chronic myeloid leukemia but with a different toxicity profile, which may impact its overall benefit. Reported toxicities include pleural effusions and pulmonary hypertension, and although the incidence of these events is well described, response to therapy and impact of dose modifications on toxicity has not been comprehensively characterized in a real-world setting. We retrospectively reviewed the incidence of dasatinib adverse events in 212 chronic phase chronic myeloid leukemia patients at 17 Australian institutions. Adverse events were reported in 116 patients (55%), most commonly pleural effusions (53 patients, 25%), which was the predominant cause of permanent drug cessation. Age and dose were risk factors for pleural effusion (P < .01 and .047, respectively). Recurrence rates were higher in those who remained on 100 mg compared with those who dose reduced (P = .041); however, recurrence still occurred at 50 mg. Patients who developed pleural effusions were more likely to have achieved MR4.5 after 6 months of dasatinib than those without effusions (P = .008). Pulmonary hypertension occurred in 5% of patients, frequently in association with pleural effusion, and was reversible upon dasatinib cessation in 6 of 7 patients. Dose reductions and temporary cessations had minimal impact on MR rates. Our observations suggest that by using the lowest effective dose in older patients to minimize the effusion risk, dose modification for cytopenias, and care with concomitant antiplatelet therapy, the necessity for permanent dasatinib cessation due to toxicity is likely to be minimal in immunologically competent patients.