Long-term Results of Imatinib Discontinuation in Patients with Chronic-phase Chronic Myeloid Leukemia: A National Multicenter Prospective Study

Objective

The discovery of imatinib was a milestone for chronic myeloid leukemia (CML). As the life expectancy of CML patients has approached that of the general population, research has shifted towards improving quality of life and economic considerations. After 2010, it was shown that some patients could maintain molecular response even after discontinuing imatinib. This national multicenter prospective cohort study aimed to observe the long-term consequences of discontinuing imatinib therapy in adult chronic-phase CML patients.

Materials and Methods

We enrolled 41 CML patients from 4 different centers in this non-randomized single-arm trial. Molecular responses of all patients were re-evaluated using real-time polymerase chain reaction at a single center. The median follow-up time after imatinib discontinuation was 48 months (minimum-maximum: 6-81 months).

Results

The rate of molecular relapse-free survival at 48 months was 33.2% (confidence interval: 48.2-18.2). Twenty-seven of 41 patients lost their major molecular response, treatment was started again, and deep molecular response was re-achieved with imatinib in all cases. There was no significant relationship between molecular relapse and clinical factors such as duration of treatment or molecular response status. Discontinuing imatinib resulted in savings of approximately 4,392,000 Turkish lira or 245,150 US dollars.

Conclusion

Tyrosine kinase inhibitor discontinuation with close molecular monitoring is a safe option and provides important national economic benefits for chronic phase CML patients. This approach should be considered for all eligible patients. This is the first tyrosine kinase inhibitor discontinuation study from Türkiye.

Superior Survival in African American Patients Who Underwent Autologous Stem Cell Transplantation for Multiple Myeloma

INTRODUCTION/BACKGROUND

African American (AA) individuals have a twofold higher incidence of multiple myeloma (MM) compared with other racial groups. Outcomes are affected by factors such as disparate access to care as well as differences in disease biology.

PATIENTS AND METHODS

We conducted a single-institution analysis to evaluate the effect of AA race on outcomes of MM patients who underwent autologous stem cell transplantation (ASCT) in the pre-novel and novel agent era.

RESULTS

Sixty-one (47%) patients were AA and 69 (53%) were non-AA. Overall, 78 (60%) patients received any novel agent before transplantation and 52 (40%) received only chemotherapy. More non-AA patients received initial induction with a proteasome inhibitor (40 [60%] vs. 17 [28%]; P = .0007), and were treated with post-ASCT maintenance therapy (28 [41%] vs. 14 [23%]; P = .04). Time from diagnosis to ASCT in AA patients was 10 (range, 4-144) versus 8 (range, 3-54) months in non-AA patients (P = .01). Despite this, treatment-free survival (TFS) was equivalent between the 2 groups (x vs. y). Furthermore, AA patients had greater median overall survival (OS) compared with non-AA patients (not reached vs. 108 months; P = .03) and significantly improved OS in multivariable Cox proportional hazards models (adjusted hazard ratio, 0.30; 95% confidence interval, 0.11-0.81; P = .017). Median OS, landmarked at the time of relapse, was improved in AA patients (not reached vs. 68 months for P = .05).

CONCLUSION

Our study showed with long follow-up, equivalent TFS after ASCT in AA and non-AA patients yet improved OS. Post relapse survival is improved in AA patients suggesting a better response to salvage therapy.

Sex-dependent association of circulating sex steroids and pituitary hormones with treatment-free survival in chronic lymphocytic leukemia patients

Chronic lymphocytic leukemia (CLL) is not considered a hormone-regulated cancer although sex is a recognized risk factor with men more frequently diagnosed and developing progressive disease. We hypothesized that variable hormonal exposure may have a sexually dimorphic influence on treatment-free survival (TFS). In 156 CLL cases, we quantitatively profiled 29 circulating steroids (progesterone, adrenal precursors, androgens, estrogens, and catechol estrogens) as well as luteinizing hormone (LH) and follicle-stimulating hormone. Median TFS was shorter for men than that for women (80.7 vs. 135.0 months, P = 0.033). Circulating hormone profiles in CLL patients were significantly different from those of healthy donors. In male CLL cases, higher LH levels were associated with shorter TFS (adjusted hazard ratio (HR_adj) 2.11; P = 0.004). In female CLL cases, high levels of the potent androgens testosterone and dihydrotestosterone and the sum of methoxy estrogens were associated with an improved TFS with HR_adj values of 0.24 (P = 0.007), 0.54 (P = 0.023), and 0.31 (P = 0.034), respectively. Reduced TFS was observed for women with CLL exhibiting high expression of the steroid-inactivating UGT2B17 enzyme. This study is the first to establish a link between the outcome of CLL patients, sex steroids, and pituitary hormones, revealing a sex-specific hormonal imbalance associated with disease progression.