Ternary complex dissociation kinetics contribute to mutant-selective EGFR degradation

PROTACs in Ovarian Cancer: Current Advancements and Future Perspectives

Ovarian cancer is the deadliest gynecologic malignancy. The majority of patients diagnosed with advanced ovarian cancer will relapse, at which point additional therapies can be administered but, for the most part, these are not curative. As such, a need exists for the development of novel therapeutic options for ovarian cancer patients. Research in the field of targeted protein degradation (TPD) through the use of proteolysis-targeting chimeras (PROTACs) has significantly increased in recent years. The ability of PROTACs to target proteins of interest (POI) for degradation, overcoming limitations such as the incomplete inhibition of POI function and the development of resistance seen with other inhibitors, is of particular interest in cancer research, including ovarian cancer research. This review provides a synopsis of PROTACs tested in ovarian cancer models and highlights PROTACs characterized in other types of cancers with potential high utility in ovarian cancer. Finally, we discuss methods that will help to enable the selective delivery of PROTACs to ovarian cancer and improve the pharmacodynamic properties of these agents.

EGFR degraders in non-small-cell lung cancer: Breakthrough and unresolved issue

The epidermal growth factor receptor (EGFR) has been well validated as a therapeutic target for anticancer drug discovery. Osimertinib has become the first globally accessible third-generation EGFR inhibitor, representing one of the most advanced developments in non-small-cell lung cancer (NSCLC) therapy. However, a tertiary Cys797 to Ser797 (C797S) point mutation has hampered osimertinib treatment in patients with advanced EGFR-mutated NSCLC. Several classes of fourth-generation EGFR inhibitors were consequently discovered with the aim of overcoming the EGFRC797S mutation-mediated resistance. However, no clinical efficacy data of the fourth-generation EGFR inhibitors were reported to date, and EGFRC797S mutation-mediated resistance remains an "unmet clinical need." Proteolysis-targeting chimeric molecules (PROTACs) obtained from EGFR-TKIs have been developed to target drug resistance EGFR in NSCLC. Some PROTACs are from nature products. These degraders compared with EGFR inhibitors showed better efficiency in their cellular potency, inhibition, and toxicity profiles. In this review, we first introduce the structural properties of EGFR, the resistance, and mutations of EGFR, and then mainly focus on the recent advances of EGFR-targeting degraders along with its advantages and outstanding challenges.

Two in one: the emerging concept of bifunctional antibodies

Therapeutic antibodies have become indispensable for treating a wide range of diseases, and their significance in drug discovery has expanded considerably over the past few decades. Bifunctional antibodies are now emerging as a promising new drug modality to address previously unmet needs in antibody therapeutics. Distinct from traditional antibodies that operate through an 'occupancy-based' inhibition mechanism, these innovative molecules recruit the protein of interest to a 'biological effector,' initiating specific downstream consequences such as targeted protein degradation or posttranslational modifications. In this review, we emphasize the potential of bifunctional antibodies to tackle diverse biomedical challenges.

Targeted degradation of extracellular secreted and membrane proteins

Targeted protein degradation (TPD) involving chimeric molecules has emerged as one of the most promising therapeutic modalities in recent years. Among various reported TPD strategies, proteolysis-targeting chimeras (PROTACs) stand out as a significant breakthrough in small-molecule drug discovery and have garnered the most attention to date. However, PROTACs are mainly capable of depleting intracellular proteins. Given that many important therapeutic targets such as cytokines, growth factors, and numerous receptors are membrane proteins or secreted extracellularly, there is interest in the development of novel strategies to degrade these protein categories. We review advances in this emerging area and provide insights to enhance the development of novel TPDs targeting extracellular proteins.