A Study to Evaluate Available Treatment Information of Ponatinib, Bosutinib, Imatinib, Dasatinib and Nilotinib in Adults With Chronic Myeloid Leukemia

Inclusion criteria:

Participants will be included in the study if they:

1. had ≥1 prescription for TKI (imatinib, dasatinib, nilotinib, bosutinib, or ponatinib) from April 1, 2013-March 31, 2017;

   * For participants with ponatinib use, the first ponatinib prescription date will be defined as the index date; for participants with bosutinib but not ponatinib use, the first bosutinib prescription date will be defined as the index date; and for participants without ponatinib and bosutinib use, the first imatinib, dasatinib, nilotinib prescription date will be defined as the index date.
   * Participants with \>1 type of TKI on the index date will be dropped.
2. had ≥1 medical diagnosis for CML (International Classification of Diseases, Ninth Revision, Clinical Modification \[ICD-9-CM\]: 205.1; ICD-10-CM: C92.1) any time prior to the index date or within 6 months post-index date; diagnosis codes in the primary or secondary position will be used; the first CML diagnosis date will be designated as the initial CML diagnosis date;
3. were aged ≥18 years on the index date;
4. were active in the Humedica EMR data 6 months pre- and post-index date, indicated by the first and last healthcare activity in the data;

   * Participant data will be assessed until the earliest of switch to another TKI, disenrollment, death, or study end date. The minimum required duration of follow-up can be further revised based on the average duration of first-line treatment.
   * Participants who died in 6 months will be included.

Exclusion criteria:

Participants will be excluded from the study if they:

1. had ≥1 prescription for their index TKI (imatinib, dasatinib, nilotinib, bosutinib, or ponatinib) any time prior to the index date.
2. This will allow ≥6-month wash-out period, and ensure we are capturing second line participants.