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Treatment Efficacy and Resistance Mechanisms Using the Second-Generation ALK Inhibitor AP26113 in Human
M Ceccon1, L Mologni2, G Giudici3
1Department of Health Science, University of Milano-Bicocca, Monza, Italy. mceccon.manuscript@gmail.com.
Unlabelled:
ALK is a tyrosine kinase receptor involved in a broad range of solid and hematologic tumors. Among 70% to 80% of ALK(+) anaplastic large cell lymphomas (ALCL) are caused by the aberrant oncogenic fusion protein NPM-ALK. Crizotinib was the first clinically relevant ALK inhibitor, now approved for the treatment of late-stage and metastatic cases of lung cancer. However, patients frequently develop drug resistance to Crizotinib, mainly due to the appearance of point mutations located in the ALK kinase domain. Fortunately, other inhibitors are available and in clinical trial, suggesting the potential for second-line therapies to overcome Crizotinib resistance. This study focuses on the ongoing phase I/II trial small-molecule tyrosine kinase inhibitor (TKI) AP26113, by Ariad Pharmaceuticals, which targets both ALK and EGFR. Two NPM-ALK(+) human cell lines, KARPAS-299 and SUP-M2, were grown in the presence of increasing concentrations of AP26113, and eight lines were selected that demonstrated resistance. All lines show IC50 values higher (130 to 1,000-fold) than the parental line. Mechanistically, KARPAS-299 populations resistant to AP26113 show NPM-ALK overexpression, whereas SUP-M2-resistant cells harbor several point mutations spanning the entire ALK kinase domain. In particular, amino acid substitutions: L1196M, S1206C, the double F1174V+L1198F and L1122V+L1196M mutations were identified. The knowledge of the possible appearance of new clinically relevant mechanisms of drug resistance is a useful tool for the management of new TKI-resistant cases.
Implications:
This work defines reliable ALCL model systems of AP26113 resistance and provides a valuable tool in the management of all cases of relapse upon NPM-ALK-targeted therapy.
Insights
This study investigates resistance mechanisms to AP26113, a tyrosine kinase inhibitor (TKI), in anaplastic large cell lymphoma (ALCL) models. Findings reveal NPM-ALK overexpression and specific ALK mutations as key drivers of AP26113 resistance.
Area of Science:
- Oncology
- Molecular Biology
- Pharmacology
Background:
- Anaplastic large cell lymphoma (ALCL) often involves the NPM-ALK fusion protein.
- ALK tyrosine kinase inhibitors (TKIs) like Crizotinib are used for advanced ALK-positive cancers.
- Drug resistance, often due to ALK mutations, limits TKI efficacy.
Purpose of the Study:
- To establish and characterize models of resistance to the ALK/EGFR inhibitor AP26113 in ALCL.
- To elucidate the molecular mechanisms underlying AP26113 resistance.
Main Methods:
- Development of AP26113-resistant NPM-ALK-positive ALCL cell lines (KARPAS-299, SUP-M2).
- Assessment of drug sensitivity (IC50 values) in resistant cell lines.
- Identification of resistance mechanisms through NPM-ALK expression analysis and ALK kinase domain mutation screening.
Main Results:
- Resistant cell lines exhibited 130- to 1,000-fold higher IC50 values compared to parental lines.
- KARPAS-299 resistant cells showed NPM-ALK overexpression.
- SUP-M2 resistant cells harbored various ALK kinase domain mutations, including L1196M, S1206C, F1174V+L1198F, and L1122V+L1196M.
Conclusions:
- Established reliable ALCL models for studying AP26113 resistance.
- Identified NPM-ALK overexpression and specific ALK mutations as key resistance mechanisms.
- Provides insights for managing patients with relapsed or refractory ALK-targeted therapy.
