Purpose: Treatment for patients with chronic lymphocytic leukemia (CLL) is often not curative. Therefore, patients with CLL eventually experience disease progression with limited therapeutic options, even if the duration of remission can be long. Median overall survival for patients with CLL is usually 8 to 12 years, but there is a large variation in survival among individual patients, ranging from several months to a normal life expectancy. This retrospective observational study describes course of treatment and occurrence of treatment failure in patients with CLL.
Methods: Adult patients with ≥ 1 diagnosis of CLL and ≥ 1 claim for a medication used to treat CLL were identified in the IMS PharMetrics Plus database (January 2008 to September 2013). Patients were excluded if they had evidence of a nonhematologic malignancy, used a non-CLL antineoplastic agent, or received a stem cell transplant during the 12-month baseline period. Initial therapy was defined as the single agent or the combination of medications used to treat CLL that was given to patients in the first 30 days following the first claim for a medication (index date) used to treat CLL. Treatment failure was identified based on earliest occurrence of one of the following events: initiation of a new treatment for CLL that was not part of the initial therapy, resumption of any CLL treatment following a minimum of 3-month break in treatment, radiotherapy, stem cell transplant, hospital mortality, or hospice care.
Results: A total of 6,015 patients with CLL were identified (mean patient aged 63 years; proportion female: 36%). Patients were observed for 22.7 months on average following treatment initiation. Median time between first CLL diagnosis and first claim for a medication used to treat CLL was 102 days. Mean Charlson comorbidity index was 3.2. More frequent comorbidities were hypertension (44%), anemias (37%), coagulation deficiency (21%), diabetes without chronic complications (18%), and chronic pulmonary disease (18%). Of the 6,015 patients with CLL, 2,734 (45%) experienced treatment failure. Main observed measures for treatment failure were initiation of a new CLL treatment that was not part of the initial therapy (41%; mean time to treatment failure [TTF]: 286 days), resumption of any CLL treatment (39%; TTF: 346 days), radiotherapy (14%; TTF: 199 days), and stem cell transplant (5%; TTF: 116 days). Very few patients experienced treatment failure observed through hospice care (0.4%; TTF: 387 days).
Conclusions: A notable number (45%) of patients with CLL experienced treatment failure, which was mainly observed through initiation of alternative therapies or the need for a holiday after initial therapy. These data help in our understanding of CLL treatment failure patterns, which is a first step toward reducing the burden of disease in patients with CLL. Further research evaluating the reasons and economic implications of treatment failure is warranted.
