Long-term treatment with bosutinib in a phase 1/2 study in Japanese chronic myeloid leukemia patients resistant/intolerant to prior tyrosine kinase inhibitor treatment

Therapy for patients with chronic phase-chronic myeloid leukemia previously treated with ⩾2 tyrosine kinase inhibitors: a systematic literature review

Background

ATP-competitive tyrosine kinase inhibitors (TKIs) are the current standard of care for patients with chronic phase-chronic myeloid leukemia (CP-CML) in the first-line and second-line (2 L) setting. Treatment after 2 L is not clearly established.

Objective

The objective of this study was to summarize the available evidence to compare the efficacy and safety of interventions in the treatment of CP-CML patients who had received ⩾2 prior TKIs.

Design

A systematic literature review was performed.

Data source and methods

A systematic literature review (SLR) of studies published until May 2021, reporting clinical outcomes in adult patients with CP-CML who had received ⩾ 2 prior TKIs was performed. Studies were identified through the database searches via Ovid platform (Embase, MEDLINE Epub Ahead of Print, In-Process and Other Non-Indexed Citations, and Cochrane Central Register of Controlled Trials), the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP), bibliographic search of relevant reviews, and proceedings from the previous 3 years of the key conferences in the field of oncology.

Results

Our search identified 38 relevant studies. Among the identified studies of the current third-line treatments, the major molecular response (MMR) rate for ponatinib was 19.0-66.7%, 23.3-25.5% for asciminib, 19.2% for omacetaxine, and 13.2% for bosutinib at 6 months. The complete cytogenetic response (CCyR) rate was 21.4-64.8% for ponatinib, 38.7-40.8% for asciminib, 18-24.2% for bosutinib, and 16.1% for omacetaxine at 6 months.

Conclusion

The findings from current SLR demonstrated the lack of data for patients with CML treated with ⩾2 TKIs. TKIs such as asciminib, ponatinib, and bosutinib are valid options for those patients. Further research is needed to identify the best treatment option for patients with CML receiving later lines of therapy.

Asciminib vs bosutinib in CML patients pretreated with ≥2 tyrosine kinase inhibitors: Results from the Japanese subgroup analysis of ASCEMBL study

Asciminib, a first-in-class, allosteric inhibitor of BCR-ABL1 that acts by STAMP (Specifically Targeting the ABL Myristoyl Pocket), is a novel therapeutic option for patients with chronic myeloid leukemia (CML). In the global, phase 3, open-label ASCEMBL study in patients with CML in chronic phase (CML-CP) pretreated with ≥2 tyrosine kinase inhibitors (TKIs) (NCT03106779), asciminib (40 mg twice-daily) demonstrated significant superiority over the ATP-competitive TKI bosutinib (500 mg once daily) for the primary endpoint of major molecular response (MMR; BCR::ABL1 transcript levels on the international scale [BCR::ABL1^IS ] ≤0.1%) at week 24. Here, we report results from a descriptive subgroup analysis of Japanese patients enrolled in ASCEMBL study (data cut-off: May 25, 2020). Overall, 16 Japanese patients were randomized (asciminib, n = 13; bosutinib, n = 3). At week 24, the MMR rate with asciminib was 30.8% (4/13; 95% confidence interval [CI], 9.09-61.43). BCR::ABL1^IS ≤1% and complete cytogenic response (CCyR) at week 24 were 61.5% (8/13 patients) and 50.0% (4/8 patients), respectively. In the bosutinib group, no patient achieved MMR, CCyR, or BCR::ABL1^IS ≤1%, but results were limited by the low number of patients. The safety profile of asciminib was comparable to that previously observed in the overall study population. Findings from this Japanese subgroup analysis of the ASCEMBL study support the use of asciminib for the treatment of Japanese patients with CML-CP previously treated with ≥2 TKIs. ClinicalTrials.gov Identifier: NCT03106779.

Bosutinib in Japanese patients with newly diagnosed chronic-phase chronic myeloid leukemia: final 3-year follow-up results of a phase 2 study

Bosutinib has been evaluated for treatment of chronic-phase chronic myeloid leukemia (CP-CML) in several clinical studies, including in Japan. This open-label, single-arm, phase 2 study evaluated the efficacy and safety of bosutinib at a starting dose of 400 mg once daily in Japanese patients (n = 60) with newly diagnosed CP-CML. The minimum follow-up period was 3 years and median duration of treatment was 35.9 months. At study completion, 60% of patients were still on treatment. Cumulative rates of major molecular response (MMR), molecular response⁴ (MR⁴), and MR^4.5 at any time were 70.0%, 53.3%, and 48.3%, respectively. No patient who achieved MMR or MR⁴ had a confirmed loss of response. No patient experienced on-treatment transformation to accelerated/blast phase or died within 28 days of the last bosutinib dose. Any-grade treatment-emergent adverse events (TEAEs) occurred in 100% (grade ≥ 3: 81.7%) of patients. The most common TEAEs were diarrhea (86.7%), increased alanine aminotransferase (55.0%), and increased aspartate aminotransferase (46.7%). No new safety signals emerged during the follow-up period. Bosutinib continues to demonstrate a favorable benefit/risk profile and is an important treatment option for Japanese patients with newly diagnosed CP-CML. Optimal management of TEAEs during initial treatment with bosutinib should be prioritized.

Trial Registration: ClinicalTrials.gov ID: NCT03128411.

Safety profile of bosutinib in Japanese versus non-Japanese patients with chronic myeloid leukemia: a pooled analysis

Bosutinib has been investigated in multiple clinical trials globally, including Japan, for treatment of chronic myeloid leukemia (CML). A pooled analysis of seven Pfizer-sponsored clinical trials evaluated the safety of bosutinib in Japanese (n = 138) vs non-Japanese (n = 1210) patients with CML. First-line bosutinib was administered in 54.3% vs 41.4% of patients, and second-line or later bosutinib in the remainder. Median treatment duration was 1.4 vs 2.3 years, and median relative dose intensity 78.1% vs 90.0%. Any-grade treatment-emergent adverse events (TEAEs) occurred in 100.0% vs 98.9% (grade ≥ 3: 81.9% vs 75.2%). In both groups, the most common TEAEs relevant to bosutinib were gastrointestinal (92.8% vs 84.7%), liver function (72.5% vs 34.8%), rash (63.8% vs 37.4%), and myelosuppression (55.1% vs 50.7%). TEAEs led to dose reduction in 65.2% vs 50.6%, dose interruption in 78.3% vs 68.8%, and permanent treatment discontinuation in 30.4% vs 25.4% of patients. The safety profile of bosutinib in Japanese patients was generally consistent with that in non-Japanese patients, despite a higher incidence of gastrointestinal, liver function, and rash events. TEAEs were largely manageable with dose modifications and supportive care in both groups. These data may help optimize TEAE management and outcomes in Japanese patients receiving bosutinib for CML. Trial registration ClinicalTrials.gov: NCT02130557, NCT03128411, NCT00574873, NCT00261846, NCT01903733, NCT00811070, NCT02228382.

Screening tumor specificity targeted by arnicolide D, the active compound of Centipeda minima and molecular mechanism underlying by integrative pharmacology

ETHNOPHARMACOLOGICAL RELEVANCE

Herb-derived anti-tumor agents, such as paclitaxel and vincristine, exert significant but varied effectivenesses towards different cancer types. Similarly, Centipeda minima (CM) is a well-known traditional Chinese medicine that has been used to treat rhinitis, relieve pain and reduce swelling, and recently found to exert overwhelming anti-tumor effects against breast cancer, colon cancer, and nasopharyngeal carcinoma with different response rates. However, what is the optimizing cancer model that benefits most from CM, and what is the specific target underlying still require more exclusive and profound investigations.

AIMS OF THE STUDY

This study aimed to explore the dominant tumor model and specific target of CM by integrative pharmacology and biological experiments.

MATERIALS AND METHODS

The most predominant and specific cancer types that are sensitive to CM were screened and identified based on a combination network pharmacology and bioinformatics analysis. Compound-target network and protein-protein interaction of CM-related cancer targets were carried out to determine the most abundant active compound. Simultaneously, the priority target responsible for CM-related anti-tumor efficacy was further validated by molecular docking and in vitro experiments.

RESULTS

In total, approximately 42% (8/19) of the targets were enriched in prostate cancer (p = 1.25E-09), suggesting prostate cancer would be the most sensitive tumor response to CM-related efficacy. Furthermore, we found that arnicolide D (ARD), the most abundant and representative active compound of CM, could directly bind to Src with binding energy of -7.3 kcal/mol, implying Src would be the priority target responsible for CM-related anti-tumor efficacy. Meanwhile, the results were further validated by solvent-induced protein precipitation (SIP) assay. In addition, PCR and WB results also revealed that either CM or ARD could not influence the gene expression of Src, while significantly decreased its protein expression instead, which further suggested that ARD might markedly shortene the Src protein half-life to promote Src protein degradation, thereby achieving significant anti-prostate cancer efficacy.

CONCLUSION

Our findings not only suggest CM as a promising Src-targeting candidate for prostate cancer treatment, but also bring up a strategy for understanding the personalization of herbal medicines by using integrative pharmacology.

Correlation of plasma concentration and adverse effects of bosutinib: standard dose or dose-escalation regimens of bosutinib treatment for patients with chronic myeloid leukemia

Purpose

To investigate the exposure-toxicity relationship of bosutinib and to identify the target trough plasma concentration (C₀).

Methods

The toxicity and C₀ of bosutinib in Japanese chronic myeloid leukemia (CML) patients were monitored every 2 weeks for the first 3 months of treatment, and subsequently once a month during the 6 months after beginning 500 mg/day of standard dose (SD group, n = 10) or beginning 100 mg/day and increased by 100 mg every 2 weeks of dose escalation (DE group, n = 15).

Results

Nine of 10 patients (90%) in the SD group were not able to continue bosutinib therapy without interruption due to adverse events, compared to 2 patients (13.5%) in the DE group. The total duration of treatment interruption was 35 and 14 days in the SD and DE groups, respectively. The median time until liver dysfunction or diarrhea was day 28 and day 1 in the SD group, and day 53.5 and day 19 in the DE group, respectively. The cumulative dose of bosutinib was comparable between the SD and DE groups (51,700 vs. 53,550 mg, respectively). At 6 months, the median C₀ was 63.7 ng/mL and 63.0 ng/mL in the SD and DE groups, respectively. Liver dysfunction (all grades) and diarrhea (> grade 2) were prevalent in quartile 4 of C₀ (> 91.0 ng/mL), as calculated by the total C₀ distribution.

Conclusions

The DE regimen was better suited to avoid treatment interruption. The daily dose of bosutinib might be adjusted based on target C₀ to avoid adverse events by therapeutic drug monitoring in general practice.