Lower Molecular Response Rates Observed Among Underserved Patients With CML

Key Takeaways:

• In a chart review of patients with chronic myeloid leukemia (CML) from underrepresented backgrounds, 82.4% had a comorbidity at the time of diagnosis.
• More than half of patients received second-line treatments, and over one-fourth received even later lines of therapy (LOT).
• More than half of patients discontinued first- or second-line treatment, with inadequate response and treatment intolerance among the most common reasons.

Despite improvements in the CML treatment landscape, disparities in treatment and health outcomes persist among underrepresented populations.

Study Methods and Outcomes

Researchers conducted a multicenter retrospective chart review of 108 patients with CML who were treated at Harbor-UCLA Medical Center, Olive View-UCLA Medical Center, and Los Angeles General Medical Center between January 2015 and December 2024.

Data collected included demographics, comorbidities, treatment selection, and major molecular response (MMR) rates.

The primary outcome was the rate of MMR3. Secondary outcomes included time between treatment initiation and MMR, rates of and reasons for TKI discontinuation, and rates of disease progression.

Patient Characteristics

Within the study population, 40% of patients were female and 60% were male. The median age at diagnosis was 46 years, compared with 65 years represented in previous clinical trials.

Over half (58.3%) of patients were Hispanic, followed by Black (13.9%), Asian or Pacific Islander (4.5%), and White (3.7%) patients. Race or ethnicity was classified as other or unknown for 19.4% of patients.

Approximately 59.2% of patients lived in zip codes with household incomes below the national average.

Most patients (82.4%) had at least 1 comorbidity at diagnosis, including hypertension (28.7%) and diabetes (20.4%). Over two-thirds of patients had a body mass index (BMI) greater than 25.

First-Line Treatment Patterns

Imatinib was the most common first-line treatment option, received by 64.8% of patients, followed by dasatinib (31.5%). One patient received nilotinib, and 1 received interferon.

During first-line therapy, 44.4% of patients achieved MMR3 or better, with an average 26.5 months between treatment initiation and MMR achievement.

Over one-third (34.3%) of patients experienced side effects, 13.9% reported treatment adherence issues, and 3.7% experienced both. Overall, 57.4% of patients discontinued treatment due to inadequate response (45.1%), treatment intolerance (27.4%), or both (16.1%).

Second-Line Treatment Patterns

More than half of patients (56.5%) received second-line treatment. Dasatinib was the most common therapy (60.7%), followed by imatinib (11.3%), asciminib (9.7%), nilotinib (8.1%), ponatinib (4.8%), and interferon (3.2%). One patient received bosutinib.

Nearly one-third (32.8%) of patients achieved MMR3 or better, with an average 13 months between treatment initiation and MMR achievement.

Over one-third (34.4%) of patients experienced side effects, and 6.6% had issues with treatment adherence. Treatment discontinuation occurred among 55.8% of patients due to inadequate response (38.2%), treatment intolerance (41.1%), or both (8.8%).

Successive Treatment Patterns

Of the original 108 patients, 27% received third-line treatment and 13.8% received fourth-line treatment. MMR3 or better was achieved by 8 patients receiving third-line therapy and 7 receiving fourth-line therapy.

Treatment discontinuation occurred among 16 patients receiving third-line therapy and 2 receiving fourth-line therapy. Among those receiving third-line treatments, 37.5% discontinued due to inadequate response, 25% due to treatment intolerance, and 31.3% due to both reasons. Treatment intolerance was the only documented reason for discontinuing fourth-line therapy.

Implications for Managed Care

Despite the wide variety of available treatment options, patients with CML from underserved populations had lower MMR rates compared to previous clinical trials. Patients in this study also had a high burden of comorbidities and socioeconomic barriers, which may contribute to disparities in treatment outcomes.

These findings highlight the need for more research on the socioeconomic, biologic, and environmental factors influencing outcomes.

The authors concluded, “Our findings offer a data-informed basis for heightened and holistic vigilance when caring for underserved CML patients, and it is crucial that this population continues to be represented in future cohort studies.”

Reference

Zheng D, Nold T, Ramakrishnan N, Kim K, Tomassetti S. A real-world management of chronic myelogenous leukemia in an underserved patient cohort at a Los Angeles safety-net health system: tyrosine kinase inhibitor treatment patterns and outcomes from 2015 to 2024. Cancer Med. 2026;15(9):e72223. doi:10.1002/cam4.72223