Benefits and risks of ponatinib versus bosutinib following treatment failure of two prior tyrosine kinase inhibitors in patients with chronic phase chronic myeloid leukemia: a matching-adjusted indirect comparison

Comparative efficacy and safety of different doses of ponatinib versus other tyrosine kinase inhibitors for the treatment of chronic myeloid leukemia: a systematic review and network meta-analysis

OBJECTIVE

Ponatinib was recommended with caution because of its high risk of causing arterial occlusion events in chronic myeloid leukemia (CML) patients. The purpose of this study was to understand the efficacy and safety of different doses of ponatinib in the treatment of CML, and to compare it with other tyrosine kinase inhibitors (TKIs).

METHOD

A network meta-analysis (NMA) was conducted by searching randomized controlled trials (RCTs) of ponatinib in patients with CML to compare the efficacy and safety of ponatinib, and ranked under the cumulative ranking curve (SUCRA) to evaluate the optimal treatment.

RESULTS

A total of seven articles with eight RCTs were included in this study, involving 45 mg, 30 mg and 15 mg ponatinib doses. Seven outcome indexes were analyzed. The results showed that 45 mg ponatinib was superior to other doses of ponatinib and other TKIs in CCyR, MCyR and CHR, but the incidence of SAEs and AOEs was significantly higher than other treatment regimens.

CONCLUSION

Ponatinib, with an initial dosage of 45 mg and a gradual reduction to 15 mg, may be a more favorable option for patients with CML at all stages of disease progression, rather than just those in the chronic phase of CML.

Matching-adjusted indirect comparison of asciminib versus other treatments in chronic-phase chronic myeloid leukemia after failure of two prior tyrosine kinase inhibitors

PURPOSE

The current standard of care for chronic-phase chronic myeloid leukemia (CP-CML) is tyrosine kinase inhibitors (TKIs). Treatment recommendations are unclear for CP-CML failing ≥ 2 lines of treatment, partly due to the paucity of head-to-head trials evaluating TKIs. Thus, matching-adjusted indirect comparisons (MAICs) were conducted to compare asciminib with competing TKIs in third- or later line (≥ 3L) CP-CML.

METHODS

Individual patient-level data for asciminib (ASCEMBL; follow-up: ≥ 48 weeks) and published aggregate data for comparator TKIs (ponatinib, nilotinib, and dasatinib) informed the analyses. Major molecular response (MMR), complete cytogenetic response (CCyR), and time to treatment discontinuation (TTD) were assessed, where feasible.

RESULTS

Asciminib was associated with statistically significant improvements in MMR by 6 (relative risk [RR]: 1.55; 95% confidence interval [CI]: 1.02, 2.36) and 12 months (RR: 1.48; 95% CI: 1.03, 2.14) vs ponatinib. For CCyR, the results vs ponatinib were similar by 6 (RR: 1.11; 95% CI: 0.81, 1.52) and 12 months (RR: 0.97; 95% CI: 0.73, 1.28). Asciminib was associated with improvements in MMR by 6 months vs dasatinib but with a CI overlapping one (RR 1.52; 95% CI: 0.66, 3.53). Asciminib was associated with statistically significant improvements in CCyR by 6 (RR: 3.57; 95% CI: 1.42, 8.98) and 12 months (RR: 2.03; 95% CI: 1.12, 3.67) vs nilotinib/dasatinib. Median TTD was unreached for asciminib in ASCEMBL. However, post-adjustment asciminib implied prolonged TTD vs nilotinib and dasatinib, but not vs ponatinib.

CONCLUSION

These analyses demonstrate favorable outcomes with asciminib versus competing TKIs, highlighting its therapeutic potential in ≥ 3L CP-CML.

Geometric approaches to assessing the numerical feasibility for conducting matching-adjusted indirect comparisons

We discuss how to handle matching-adjusted indirect comparison (MAIC) from a data analyst's perspective. We introduce several multivariate data analysis methods to assess the appropriateness of MAIC for a given set of baseline characteristics. These methods focus on comparing the baseline variables used in the matching of a study that provides the summary statistics or aggregated data (AD) and a study that provides individual patient level data (IPD). The methods identify situations when no numerical solutions are possible with the MAIC method. This helps to avoid misleading results being produced. Moreover, it has been observed that sometimes contradicting results are reported by two sets of MAIC analyses produced by two teams, each having their own IPD and applying MAIC using the AD published by the other team. We show that an intrinsic property of the MAIC estimated weights can be a contributing factor for this phenomenon.

Patient preferences for frontline therapies for Philadelphia chromosome-positive acute lymphoblastic leukemia: a discrete choice experiment

Aim: We examined the preferences of adults with Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ ALL) for benefits and risks of tyrosine kinase inhibitors combined with chemotherapy for first-line treatment. Methods: In a discrete choice experiment, 201 patients chose between hypothetical treatment alternatives with varied levels of remission duration and overall survival (OS), and risks of major cardiovascular (CV) events and myelosuppression. Results: Although OS was the most important attribute to patients with Ph+ ALL, they were willing to tolerate a 2.9% increase in CV risk for 1 additional month of OS. Older patients (>59 years) and patients not in remission were less likely to tolerate increased CV risk. Conclusion: Preferences and risk tolerance varied between patients, highlighting the importance of shared decision making when selecting treatments for Ph+ ALL.

Comparison of incidence/occurrence of cardiovascular events between ponatinib vs bosutinib among patients with at least one prior line of tyrosine kinase inhibitors in chronic myeloid leukemia in a community setting in the United States

INTRODUCTION

In this real-world study, the incidence of cardiovascular events (CV) including major adverse cardiac events (MACE), arterial occlusive events (AOE), and venous occlusive events (VOE) was evaluated in chronic myeloid leukemia (CML) patients treated with ponatinib or bosutinib in a US commercial database population.

MATERIALS AND METHODS

CML patients aged ≥18 years with use of 1 or 2 prior tyrosine kinase inhibitors prescribed bosutinib or ponatinib were selected from the IBM® MarketScan® Research database. Cox proportional hazard model analyses were conducted to examine any difference in CV event risk.

RESULTS

Ponatinib and bosutinib was associated with similar incidence and risk of CV events, including MACEs (HR: 1.02; 95% CI: 0.35, 3.01), AOEs (HR: 0.90; 95% CI: 0.43, 1.85) and VOEs (HR: 0.92; 95% CI: 0.44, 1.94).

CONCLUSION

Treatment with ponatinib or bosutinib was not associated with significant differences in the incidence of CV events in CML patients.

Cost Effectiveness of the Third-Generation Tyrosine Kinase Inhibitor (TKI) Ponatinib, vs. Second-Generation TKIs or Stem Cell Transplant, as Third-Line Treatment for Chronic-Phase Chronic Myeloid Leukemia

BACKGROUND AND OBJECTIVES

Third-line treatment options for patients with chronic-phase chronic myeloid leukemia include tyrosine kinase inhibitors and allogeneic hematopoietic stem cell transplantation (alloHSCT). The objective of this study was to develop a Markov model with a lifetime time horizon to assess the cost effectiveness of ponatinib for third-line chronic-phase chronic myeloid leukemia vs. second-generation tyrosine kinase inhibitors (dasatinib, nilotinib, bosutinib) or alloHSCT from the public healthcare system perspective in Germany, Sweden, and Canada.

METHODS

Clinical outcomes were derived from the literature, and from patient-level data (phase II PACE trial) for ponatinib. Resource use included drugs, alloHSCT, monitoring and follow-up, adverse events, and end-of-life care; costs were based on national tariffs. Quality-adjusted life-years (QALYs) were calculated using chronic myeloid leukemia health-state utilities from an international time-trade-off study. Costs and benefits were discounted at 3% per annum for Germany and Sweden, and 5% for Canada.

RESULTS

Ponatinib yielded more discounted QALYs than any second-generation tyrosine kinase inhibitor/alloHSCT in all three countries, mainly owing to better response rates and longer durations of response. Incremental cost-effectiveness ratios for ponatinib vs. second-generation tyrosine kinase inhibitors were US$21,543-37,755/QALY in Germany, $24,018-38,227/QALY in Sweden, and $43,001-58,515/QALY in Canada. Ponatinib was dominant over alloHSCT in Germany, while incremental cost-effectiveness ratios for ponatinib vs. alloHSCT in Sweden and Canada were $715/QALY and $31,534/QALY, respectively.

CONCLUSIONS

Ponatinib may improve outcomes (mainly because of higher response rates and longer response durations) at an acceptable cost level compared with other third-line treatment options for chronic-phase chronic myeloid leukemia in Germany, Sweden, and Canada; however, the lack of an indirect comparison is a limitation of our study.

Tyrosine Kinase Inhibitors Available for Chronic Myeloid Leukemia: Efficacy and Safety

Chronic myeloid leukemia (CML) is currently a disease in which patients can enjoy a near normal life-expectancy. However, since the majority of patients will need to remain on treatment indefinitely, physicians in care of CML patients need be familiar with the indications and toxicities of all approved tyrosine kinase inhibitors (TKI). In clinical practice, there are five TKI (imatinib, nilotinib, dasatinib, bosutinib, and ponatinib) that are available in different scenarios and have distinct safety profiles. Decisions regarding first line treatment must be based on CML risk, comorbidities, and patients expectations. Despite the excellent outcome, half of the patients will eventually fail (due to intolerance or resistance) to first line treatment, with many of them requiring a third or even further lines of therapy. When selecting for such patients, it is essential to distinguish between failure and intolerance to previous TKIs. In the present review, we will address all these issues from a practical point of view.