Real-world data suggest that management guidelines for chronic myeloid leukemia (CML) are not being followed in the United Kingdom.
However, the data also suggest that “excellent” overall survival (OS) outcomes are achievable with currently available tyrosine kinase inhibitors (TKIs), according to researchers.
They presented these findings at the EHA 2022 Hybrid Congress.
The researchers used the UK National Registry for CML patients to understand the real-world management of CML. The registry captures baseline and yearly follow-up data from contributing centers.
For this investigation, a treatment episode was defined as the period during which a patient received a specific TKI. The researchers used the 2013 version of the European LeukemiaNet guidelines to define treatment milestones. Treatment switches for each milestone time point were counted if they occurred before the next milestone.
The researchers had baseline data for 748 CML patients from 43 centers. The team had follow-up data for 570 patients and treatment data for 534 patients. The patients’ median age at diagnosis was 53.3 years (range, 14.6-95.1 years), and 53% of patients were men. The median follow-up was 4.7 years (range, 0.1-23.7 years).
Molecular monitoring data were available for 540 patients. Most patients (63%) had a median molecular monitoring frequency of every 3 months or less, and 31% had a median frequency between 3 and 6 months.
As first-line or subsequent therapy, the most commonly prescribed TKIs were imatinib (46%), nilotinib (23%), dasatinib (21%), bosutinib (14%), and ponatinib (7%).
Imatinib remained the most commonly used first-line TKI even after NICE approved second-generation TKIs in newly diagnosed CML patients.
All patients who started dasatinib upfront received the licensed first-line dose. However, 94% of patients who started imatinib upfront and 63% who started nilotinib upfront received the licensed first-line dose.
The choice of first-line TKI was not influenced by the Sokal, Euro, EUTOS, or ELTS scores, the researchers noted.
A majority of patients achieved optimal responses at 3 months (73%), 6 months (63%), and 12 months (51%).
At 6 months, 28% of patients who had suboptimal responses and 50% of those with TKI failure switched their TKI. At 12 months, 10% of suboptimal responders and 28% of those with TKI failure switched their TKI.
Among the patients who switched TKIs at least once, 40% underwent a further TKI switch.
Kinase domain mutation analysis was requested for 36% of patients who had TKI-resistant disease at 6 months and 33% of those with resistance at 12 months.
The 5-year OS probability was 93% for patients with chronic phase CML. The researchers noted that patients who achieved a complete cytogenetic response had a significantly higher OS probability than those who did not (P <.001). However, there were no significant differences in OS probability according to depth of molecular response.
Disclosures are not available for this presentation.
Nesr G, Szydlo R, Braithwaite B, et al. Real-world management of patients with chronic myeloid leukaemia (CML): First analysis from the UK National Registry for CML. Presented at EHA 2022; June 9-12, 2022. Abstract P713.