Time to Next Treatment, Health Care Resource Utilization, and Costs Associated with Ibrutinib Use Among U.S. Veterans with Chronic Lymphocytic Leukemia/Small Lymphocytic Lymphoma: A Real-World Retrospective Analysis

Clinical and economic burden of first-line chemoimmunotherapy by risk status in chronic lymphocytic leukemia

OBJECTIVES

To evaluate the trend in cytogenetic/molecular testing rate in chronic lymphocytic leukemia (CLL) and assess the clinical and economic burden of first-line (1 L) treatment with chemoimmunotherapy (CIT) by risk status.

METHODS

This retrospective cohort study identified patients with CLL from a U.S. managed care population. Medical records were obtained for eligible patients who initiated 1 L CIT between 1/1/2007 and 7/31/2019 and underwent prognostic testing to classify them as high risk (del(17p), TP53 mutation, del(11q), unmutated IGHV or complex karyotype) or as non-high risk by FISH only (non-del(17p) and non-del(11q)). Study outcomes included testing rate, time to next treatment (TTNT) or death, time to treatment failure (defined as time to change of therapy, non-chemotherapy intervention, hospice care or death), and total plan paid costs (medical + pharmacy) per patient per month (PPPM) in the 1 L period. Cox proportional hazard models and generalized linear models were used to calculate adjusted hazard ratio or rate ratio.

RESULTS

Among the 1,808 patients with CLL, 612 were FISH or IGHV tested and the rate of testing increased from 30% to 44% from 2007-2019. High-risk patients (n = 119) had 65% higher risk of next treatment or death (median time: 2.4 vs 3.7 years), 65% higher risk of treatment failure (median time: 3.0 vs 4.9 years), and 33% higher costs ($12,194 vs $9,055, p = 0.027) during 1 L treatment than non-high risk patients (n = 134).

CONCLUSIONS

High-risk CLL patients treated with 1 L chemoimmunotherapy have poorer clinical and economic outcomes compared to non-high risk patients. Assessment of genetic risk remains suboptimal.

Real-world Clinical Outcomes of First-Line Ibrutinib or Chemoimmunotherapy in Patients with Chronic Lymphocytic Leukemia by Risk Status

INTRODUCTION

Certain genetic features in chronic lymphocytic leukemia (CLL) are associated with inferior outcomes after chemoimmunotherapy (CIT). This retrospective study evaluated treatment patterns and clinical outcomes of patients with CLL, stratified into high-risk and non-high-risk groups, who received first-line ibrutinib or CIT therapy.

METHODS

High-risk group included confirmed presence of del(17p), del(11q), unmutated IGHV, TP53 mutations, or complex karyotype. Weighted high-risk ibrutinib and CIT groups were compared for treatment effects using inverse probability of treatment weighting. Hazard ratios [95% CI] (HR) for time to next treatment (TTNT) were analyzed using Kaplan-Meier curves.

RESULTS

Bendamustine/rituximab was the most common CIT regimen initiated for high-risk patients. During the available follow-up (median 34-35 months), 74.7% of the weighted high-risk ibrutinib group received only one line of treatment, compared with 47.2% of the weighted high-risk CIT group. The most common second-line treatment was ibrutinib for those in the CIT groups and venetoclax for the ibrutinib groups. The weighted high-risk ibrutinib group had a significantly longer TTNT (median not reached) than the weighted high-risk CIT group (median 34.4 months) and was 54% less likely to start a new treatment (HR 0.5 [0.3-0.6], P < 0.010). Among CIT-treated groups, high-risk patients had significantly shorter median TTNT than non-high-risk patients (P < 0.010). However, within the ibrutinib-treated groups, the median TTNT was similar between high-risk and non-high-risk patients (HR 2.2 [1.0-5.0]; P = 0.060).

CONCLUSION

This study found that first-line single-agent ibrutinib therapy was associated with significantly longer TTNT than CIT regimens in real-world patients with high-risk CLL. The results support the use of ibrutinib in high-risk patients. INFOGRAPHIC.