Beyond lorlatinib/lorlatinib: exploring the prospects of new fourth-generation ALK inhibitors

Lorlatinib/Lorlatinib, a targeted drug targeting ALK (anaplastic lymphoma kinase) and ROS1 gene rearrangement, has achieved remarkable results in the treatment of non-small cell lung cancer (NSCLC). Especially for patients who are resistant to other ALK inhibitors such as crizotinib, the emergence of lorlatinib is undoubtedly a great boon.

Research shows that approximately35% of patients will develop acquired resistance after using lorlatinib, which is mainly related to compound mutations that can significantly reduce the efficacy of the drug. Currently, a promising research direction is to develop more refined small macrocyclic ALK inhibitors. This class of drugs has shown great potential in combating existing resistance mechanisms.

Take TPX-0131 as an example. This new small and exquisite macrocyclic drug is undergoing IND-enabled research and has initially shown a strong inhibitory effect on most compound mutations that cause lorlatinib resistance. In addition, repotrectinib, an ALK TKI (tyrosine kinase inhibitor), has also attracted much attention. It is currently in Phase I clinical research, specifically targeting patients who are resistant to ALK TKIs. Relevant studies have shown that repotrectinib is effective in overcoming common ALK resistance mutations, such as L1196M and G1202R, bringing new hope for patients' subsequent treatment.

What is more worth mentioning is that the design of the new generationTKIs also pays special attention to improving the drug's ability to penetrate the central nervous system, especially the ability to cross the blood-brain barrier. This plays a crucial role in improving the intracranial response rate and preventing brain metastasis. Although third-generation drugs such as lorlatinib have achieved good clinical results, comprehensive comparative studies between new-generation TKIs and existing drugs are still ongoing.