Chemically Induced Degradation of Anaplastic Lymphoma Kinase (ALK)

Area of Science:

• Medicinal Chemistry
• Oncology
• Molecular Biology

Background:

• Anaplastic lymphoma kinase (ALK) is a key driver in certain cancers, including non-small-cell lung cancer (NSCLC), anaplastic large-cell lymphoma (ALCL), and neuroblastoma (NB).
• Targeting ALK for degradation offers a therapeutic strategy beyond traditional inhibition.

Purpose of the Study:

• To develop and characterize novel small molecule degraders capable of inducing ALK protein degradation.
• To evaluate the efficacy of these degraders in relevant cancer cell lines.
• To investigate potential mechanisms limiting degrader potency.

Main Methods:

• Conjugation of pyrimidine-based ALK inhibitors (e.g., TAE684, LDK378) with the cereblon ligand pomalidomide to create novel degraders.
• Assessment of degrader-induced ALK degradation in NSCLC, ALCL, and NB cell lines.
• Proteomic profiling to identify off-target kinase degradation.
• Evaluation of the impact of drug transporter ABCB1 expression on degrader potency.

Main Results:

• Successful development of the first small molecule degraders that induce ALK degradation across multiple cancer cell types.
• Degrader potency was found to be compromised by the drug transporter ABCB1 in certain cell lines.
• Proteomic analysis revealed degradation of additional kinases, including PTK2 (FAK), Aurora A, FER, and RPS6KA1 (RSK1).

Conclusions:

• Novel ALK degraders have been synthesized and validated, demonstrating potential for cancer therapy.
• ABCB1 transporter expression represents a potential resistance mechanism to these degraders.
• The developed compounds exhibit broader kinase degradation profiles, suggesting potential for polypharmacology.