Real world treatment patterns in chronic myeloid leukemia patients newly initiated on tyrosine kinase inhibitors in an U.S. integrated healthcare system

Abstract

Purpose

To evaluate treatment patterns in patients diagnosed with incident chronic myelogenous leukemia (CML) newly initiating therapy with imatinib, dasatinib, or nilotinib. Patients were followed to determine switching and discontinuation rates. Factors associated with switching or discontinuation from index TKI therapy, reasons for discontinuation based on electronic chart notes, and frequency of laboratory monitoring were assessed during the follow-up period.

Methods

A retrospective cohort study was conducted in chronic myelogenous leukemia patients aged ≥ 18 years who were identified from the Kaiser Permanente Southern California (KPSC) Cancer Registry database during the study time period of 1 January 2007 to 12 December 2013. The index date was defined as the date of the first TKI prescription (imatinib, dasatinib, or nilotinib) identified during the study time period with no prior history of TKI use within 12 months. Patients had to have continuous membership with drug benefit eligibility and no prior history of stem cell transplant (SCT) or other cancers during the 12 months prior to the index date. Baseline characteristics were identified during 12 months prior to the index date and outcomes were identified during the follow-up period after the index date. All patients were followed from index TKI therapy until end of study time period (12 December 2014), death, stem cell transplant, or disenrollment from the health plan unless one of the following occurred first: a patient switched their index therapy, or a patient discontinued their index therapy. Forward stepwise selection multivariable logistic regression models were used to evaluate factors associated with patients who continued therapy compared to those who switched or discontinued therapy with the index TKI. Chart notes were reviewed 30 days prior and 30 days post index TKI discontinuation to evaluate reasons for discontinuation. Molecular and cytogenetic testing frequency was also assessed during the follow-up period among the different patient groups.

Results

Two hundred sixteen patients were identified with incident chronic myelogenous leukemia and use of TKI therapy: 189 (87.5%) received imatinib, 19 (8.8%) received dasatinib, and 8 (3.7%) received nilotinib. The mean age on index date was 53 years and 63% were male; 103 patients (48%) continued on their index therapy, while 62 patients (28%) switched, and 51 patients (24%) discontinued.

Keywords

Chronic myeloid leukemia switching tyrosine kinase inhibitor treatment patterns molecular monitoring

Get full access to this article

View all access options for this article.

References

Cortes

Hochhaus

et al.

Front-line and salvage therapies with tyrosine kinase inhibitors and other treatments in chronic myeloid leukemia. J Clin Oncol 2011; 29: 524–531.

www.cancernetwork.com/cancer-management/CML (accessed 12 June 2015).

SEER Stat Fact Sheets: CML, http://seer.cancer.gov/statfacts/html/leuks.html (accessed 12 June 2015).

Jabbour

Cortes

et al.

Long term outcomes in the second-line treatment of chronic myeloid leukemia. Cancer 2011; 117: 897–906.

Kantarjian

Talpaz

et al.

New insights into the pathophysiology of chronic myeloid leukemia and imatinib resistence. Ann Intern Med 2006; 145: 913–923.

Henk

Woloj

et al.

Real-world analysis of tyrosine kinase inhibitor treatment patterns among patients with chronic myeloid leukemia in the United States. Clin Ther 2015; 37: 124–133.

NCCN Guidelines, www.nccn.org/JNCCN/supplements/PDF/TKI_CML_Task%20Force%20Report.full.pdf. (accessed 12 June 2015).

Darkow

Henk

Thomas

et al.

Treatment interruptions and non- adherence with imatinib and associated healthcare costs: A retrospective analysis among managed care patients with chronic myelogenous leukaemia. Pharmacoeconomics 2007; 25: 481–496.

Di Bella

Bhowmik

et al.

The effectiveness of tyrosine kinase inhibitors and molecular monitoring patterns in newly diagnosed patients with chronic myeloid leukemia in the community setting. Clin Lymph Myeloma Leuk 2015; 15: 599–605.

10.

Johnson

et al.

Healthcare resource utilization and costs associated with non-adherence to imatinib treatment in chronic myeloid leukemia patients. Curr Med Res Opin 2010; 26: 61–69.

11.

Guerin

et al.

Retrospective real-world comparison of medical visits, costs, and adherence between nilotinib and dasatinib in chronic myeloid leukemia. Curr Med Res Opin 2010; 26: 2861–2869.

12.

Noens

Van Lierde

et al.

Prevalence, determinants, and outcomes of nonadherence to imatinib therapy in patients with chronic myeloid leukemia: the ADAGIO study. Blood 2009; 113: 5401–5411.

13.

Saleh

Haislip

et al.

Assessment of treatment and monitoring patterns and subsequent outcomes among patients with chronic myeloid leukemia treated with imatinib in a community setting. Curr Med Res Opin 2014; 30: 529–536.

14.

Koebnick

Langer-Gould

Gould

et al.

Sociodemographic characteristics of members of a large, integrated health care system: comparison with us census bureau data. Perm J 2012; 16: 37–41.

15.

Derose

Contreras

Coleman

et al.

Race and ethnicity data quality and imputation using U.S. census data in an integrated health system: The Kaiser Permanente Southern California experience. Med Care Res Rev 2013; Jun;70(3):330–45.

16.

Druker

Guilhot

et al.

Five-year follow-up of patients receiving imatinib for chronic myeloid leukemia. N Engl J Med 2006; 355: 2408–2417.

17.

Deininger

Buchdunger

et al.

The development of imatinib as a therapeutic agent for chronic myeloid leukemia. Blood 2005; 105: 2640–2653.

18.

Saleh

Haislip

Sharpe

et al.

19.

Quintas-Cardema

Jabbour

. Considerations for early switch to nilotinib or dasatinib in patients with chronic myeloid leukemia with inadequate response to first-line imatinib. Leuk Res 2013; 37: 487–495.