MK-8353: Discovery of an Orally Bioavailable Dual Mechanism ERK Inhibitor for Oncology

Area of Science:

• Oncology
• Medicinal Chemistry
• Pharmacology

Background:

• The field of cancer immunotherapy is rapidly advancing, driving the search for new therapeutic targets and drugs.
• Extracellular signal-regulated kinases (ERK1/2) are key regulators of cell proliferation and survival, making them attractive targets for cancer therapy.
• Previous attempts to inhibit ERK1/2 were hampered by poor pharmacokinetic properties.

Purpose of the Study:

• To discover novel pyrrolidine-based compounds as potent and selective inhibitors of ERK1/2.
• To overcome the pharmacokinetic limitations of early-stage compounds.
• To identify a clinical candidate suitable for oral administration in cancer patients.

Main Methods:

• Synthesis and chemical characterization of a novel series of pyrrolidine derivatives.
• In vitro kinase inhibition assays to determine potency and selectivity against ERK1/2.
• Pharmacokinetic studies to assess absorption, distribution, metabolism, and excretion (ADME) properties.
• Structure-activity relationship (SAR) analysis to guide lead optimization.

Main Results:

• Compound 5, a pyrrolidine derivative, demonstrated potent ERK1/2 inhibition with high selectivity and a dual mechanism of action.
• Early compounds exhibited poor pharmacokinetic profiles, limiting their therapeutic potential.
• Development of a 3(S)-thiomethyl pyrrolidine analog (compound 7) significantly improved pharmacokinetic properties.
• Lead optimization resulted in the identification of MK-8353, a clinical candidate with favorable oral bioavailability for twice-daily dosing.

Conclusions:

• Novel pyrrolidine derivatives show promise as targeted cancer therapeutics by inhibiting ERK1/2.
• MK-8353 represents a significant advancement, offering improved pharmacokinetics for effective oral delivery.
• MK-8353 is a potential new cancer therapeutic candidate for clinical development.