First-in-class multifunctional TYMS nonclassical antifolate inhibitor with potent in vivo activity that prolongs...

Area of Science:

• Oncology
• Pharmacology
• Biochemistry

Background:

• Current thymidylate synthase (TYMS) inhibitors are limited by tumor drug resistance mechanisms, such as TYMS overexpression.
• Existing antifolates can be circumvented by cancer cells through alterations in folate metabolism.
• There is a need for novel TYMS inhibitors with improved efficacy and reduced resistance potential.

Purpose of the Study:

• To develop and characterize a novel small molecule inhibitor of TYMS.
• To evaluate the antitumor activity and safety profile of this new compound.
• To elucidate the mechanism of action and identify key structural features for optimal inhibition.

Main Methods:

• Synthesis and characterization of a novel small molecule inhibitor.
• In vitro and in vivo evaluation of antitumor activity in pancreatic xenograft and genetically engineered mouse models.
• Pharmacokinetic and pharmacodynamic studies, including assessment of TYMS expression and folate pathway alterations.
• Structure-activity relationship studies using a series of analogs.

Main Results:

• The novel inhibitor demonstrated enhanced antitumor activity compared to current fluoropyrimidines and antifolates.
• The compound did not induce TYMS overexpression and extended survival in preclinical models.
• Mechanistic studies confirmed it as a multifunctional nonclassical antifolate, inhibiting both TYMS and dihydrofolate reductase.
• The inhibitor was well tolerated and effective via both oral and intraperitoneal administration.

Conclusions:

• Nonclassical antifolate inhibitors targeting thymidylate biosynthesis represent a promising strategy for enhanced cancer therapy.
• This novel compound offers a favorable safety profile and overcomes resistance mechanisms associated with classical inhibitors.
• Further development of these inhibitors holds potential for improved patient outcomes in various cancers.