How to treat chronic myeloid leukemia (CML) in older adults

Association between plasma imatinib levels and response to treatment of chronic myeloid leukemia in patients from Manaus, Brazil

INTRODUCTION

Imatinib mesylate (IM) is the drug of choice for the treatment of chronic myeloid leukemia (CML). However, despite most of the results obtained with this therapy being positive, some patients still present a suboptimal therapeutic response or still develop some type of resistance. Therefore, the aim of this study was to evaluate IM plasma levels in CML patients treated at a referral unit in Manaus and correlate them with variables that might interfere with these levels.

METHODS

Data from 52 patients were obtained through a standardized questionnaire containing clinical, sociodemographic, lifestyle, and use of other medication information, as well as an estimate of therapeutic adherence. Additionally, blood collection was performed to measure the plasma concentration of the drug using the HPLC-UV technique. Molecular studies were done to identify the presence of polymorphism in the ABCG2 C421A membrane transporter.

RESULTS

Most patients were male with a mean age of 52 ± 12.3 years (95% CI 49.0-55.9). There was a high variation in drug concentrations in the range from 0 to 4694 ng/mL, with a mean of 1558.59 ± 989.79 ng/mL (95% CI 1283.0-1834.1).

CONCLUSION

Approximately two-thirds of patients were classified in the drug-level range considered therapeutic, and there was a correlation between plasma concentration and higher molecular response. Additionally, most individuals had the normal genotype for the ABCG2 C421A polymorphism but further studies should be performed to reveal the role of this variable in the outcome of the disease in this population.

Safety and Efficacy of TKIs in very Elderly Patients (≥75 Years) with Chronic Myeloid Leukemia

BACKGROUND

While the outcomes of chronic phase chronic myeloid leukemia (CP-CML) patients aged over 65 years have been extensively evaluated in real-life experiences, limited data exist for the very elderly population (i.e., aged ≥ 75 years), especially for next-generation tyrosine kinase inhibitors (TKIs). In this retrospective study, we sought to evaluate the safety and efficacy of TKIs in this particular setting of patients.

METHODS

We conducted a retrospective analysis of a multicenter cohort of 123 newly diagnosed CP-CML very elderly patients.

RESULTS

The median age at diagnosis was 80 years (range: 75-96). In the first line, 86.1% of patients received imatinib, 7.1% dasatinib, 5.6% nilotinib, and 0.81% received bosutinib. A total of 31 patients (25.2%) switched to second-line therapy, nine patients to a third line, and one patient to a fourth line of therapy. Resistance to treatment was the primary reason for switching therapy in both the first (64.5%) and second lines (77.7%). At diagnosis, reduced doses were administered in 36.5% of patients, in 61.2% in the second line, and in all patients in subsequent lines of therapy. In the first-line setting, 71.9% of patients achieved an early molecular response (EMR, i.e., 3-month BCR::ABL1IS < 10%); at 6, 12, and 24 months, MR3 was reached by 35.7%, 55.7%, and 75.0% of patients, respectively, with 16.6%, 35.7%, and 51.7% achieving a deep molecular response (DMR) at the same time points. Treatment-free remission (TFR) was successfully attempted in 11 patients. During the follow-up period, adverse events (AEs) were observed in 78.8% of patients, including 22 cases of cardiovascular AEs. Toxicity grade ≥ 3 was more commonly observed in patients treated with standard doses of TKIs compared to reduced doses (p = 0.033). Overall, the median follow-up was 46.62 months (range: 1.8-206.2), and 43 patients died due to non-CML-related causes. Three patients died due to disease progression to advanced (n = 1) and blastic (n = 2) phases. The 5-year overall survival (OS) for the entire cohort was 71.9% (95% CI: 0.63-0.81), with no significant difference between the patients treated with standard doses of TKIs compared to those treated with reduced doses (p = 0.35).

CONCLUSIONS

TKIs appear to be safe and effective even in very elderly CML patients, and dose optimization strategies yield satisfactory molecular responses for adequate disease control with an improved safety profile.

Long term follow-up of frontline Dasatinib in older patients with chronic myeloid leukemia in chronic phase treated outside clinical trials: a real-life cohort observational study

BACKGROUND

A limited amount of data has been published in chronic-phase chronic myeloid leukemia (CP-CML) patients aged >75 years treated frontline with second-generation tyrosine kinase inhibitors.

AIMS

To address this issue in a clinical 'real-life' setting, we retrospectively analyzed 45 CP-CML patients (pts) followed in 20 Italian Centers and treated frontline with dasatinib (DAS).

PATIENTS AND METHODS

Median age was 78.4 years (range 75-89.2 years). DAS starting dose was 100 mg QD in 35 pts (77.7%), 80 mg QD in 1 pts (2.2%) and 50 mg QD in 9 pts (20.1%), respectively. The median follow-up was 42.6 months (IQR 20.4 - 63.3).

RESULTS

Grade 3 and 4 side effects, both hematological and non-hematological, were detected in 6 (13.3%) and 12 (26.6%) pts, respectively. Pleural effusions of all grades occurred in 13 pts (28.8%) after a median period of DAS exposure of 14.7 months (IQR 3.0 - 33.1). The rates of DAS dose reduction and permanent drug discontinuation were 53.3% and 20.0%, respectively. As the best response, 42/45 patients (93.3%) achieved a complete cytogenetic response (CCyR), 35/45 (77.7%) a major molecular response (MMR) and 24/45 (53.3%) a deep molecular response (both MR 4.0 and MR 4.5). Only 1 patient (2.2%) progressed to the blast phase after 13 months of therapy; 8 deaths were observed (1 CML-related and 7 CML-unrelated). Cumulative event-free survival and overall survival at 36 months were 64.7% (95%, CI 49.4 - 80.0) and 82.3% (95%, CI 70.3-94.3), respectively.

CONCLUSION

These findings, although evaluated in a limited and selected cohort of patients, suggest that DAS might be effective in older patients (aged >75 years) affected by CP-CML with acceptable toxicity.