𝗖𝗼𝗳𝗳𝗲𝗲 & 𝗖𝗵𝗲𝗺𝗶𝘀𝘁𝗿𝘆 – 𝗣𝗮𝗽𝗲𝗿 #𝟮
𝗧𝗶𝘁𝗹𝗲: Recent Advances in Targeting the “Undruggable” Proteins: From Drug Discovery to Clinical Trials
𝗝𝗼𝘂𝗿𝗻𝗮𝗹: Nature Signal Transduction and Targeted Therapy (https://lnkd.in/ehzFUFzM)
𝗣𝘂𝗯𝗹𝗶𝗰𝗮𝘁𝗶𝗼𝗻 𝗗𝗮𝘁𝗲: 09/06/2023
This past week has been incredibly promising for pharmaceutical development, especially in creating therapeutics for previously unreachable targets. While reading a recent article in Nature Medicine titled, “PROTAC Protein Degraders to Drug the Undruggable Enter Phase 3 Trials,” I thought I should highlight some of the exciting emerging therapeutic modalities.
For most of pharmaceutical history, targeted therapeutics have relied on (𝟭) the discovery of a disease-related target (normally an enzyme or other protein) and (𝟮) subsequent development of a small molecule agonist or antagonist of said target. This inherently constrains pharmaceutical development to targets with an active site capable of being inhibited in such a manner. However, many proteins lack such a site and were overlooked as potential targets. Similarly, many targets have been labeled “undruggable” due to complex structure or function. Today, new therapeutic modalities capable of drugging the “undruggable” are closer than ever and the results are promising…
The paper discusses a variety of innovative approaches, but one of the most promising is that of targeted protein degradation. In this field, PROTACs have emerged as a powerful tool. PROTACs (Proteolysis Targeting Chimeras) are poly-functional molecules which “hijack” the cell’s natural degradation machinery (ubiquitin proteasome pathway) to eliminate targets of interest. They normally consist of a target ligand, a flexible linker, and an E3 ligase ligand. The PROTAC molecule binds to the target and the E3 ligase simultaneously, bringing them into proximity with one another. This allows the E3 ligase to “tag” the target protein for subsequent degradation.
The unique features of the PROTAC mechanism of action are (𝟭) They are not classical inhibitors; Rather than simply impeding native protein activity, they degrade their targets and as such are effective until the protein is synthesized once again by the cell. (𝟮) They are not stoichiometric; One PROTAC molecule can inactivate multiple target proteins whereas a classical small molecule acts on a 1:1 basis. (𝟯) They are highly customizable and do not rely on classical design methods; A PROTAC’s target ligand does not need to bind to specific active site, so long as it can bind to some region of its target, it will generally be effective.
We are truly at a turning point in science where we are developing amazing technologies to deal with things we’ve always understood to be a part of the human condition.