Pfizer’s ritlecitinib, a first-in-class, selective, oral covalent inhibitor of JAK3 and the TEC family of kinases, was FDA-approved in June 2023 for the treatment of severe alopecia areata. Ritlecitinib derives its JAK-family kinase selectivity from the covalent modification of a unique cysteine on JAK3. This annotation reviews the discovery of ritlecitinib, highlighting the interpretation of selectivity assays, the PK optimization, the evolution of the JAK3 therapeutic hypothesis, and how this 2023 Molecule of the Year nominee has become a classic case study for covalent drug discovery.

An old BMS program revitalized as a first-in-class drug in a new indication. Despite Travere Therapeutics having a checkered industry history due to ties to Martin Shrkeli, there appears to be potentially differentiating efficacy for sparsentan’s ( Filspari ) accelerated approval thanks to its novel dual-antagonistic mechanism. It’s also [...]

Inavolisib is a PI3Kα isoform-selective kinase inhibitor and monovalent degrader of the mutant p110α catalytic subunit of mutant PI3Kα. The molecule selectively depletes mutant p110α in cancer cells with active RTK (receptor tyrosine kinase) signaling and is in several ongoing or planned Ph. III trials for breast cancer. In October 2024, it received FDA approval for use in combination with palbociclib and fulvestrant to treat adults with endocrine-resistant, PIK3CA-mutated, HR+/HER2- breast cancer. This article explains how it works, how it was discovered, and why it matters.

The arachidonic acid (AA) metabolite, 20-hydroxy-5,8,11,14-eicosatetranoic acid (20-HETE), has been extensively studied as a modulator of kidney function and a mediator of kidney diseases over decades. The receptor for 20-HETE, the G-coupled protein receptor GPR75, was only recently identified (2017), and GPR75/20-HETE pathway modulators are of industry interest in many disease areas including obesity (e.g. 2020 Regeneron patent filing) and kidney diseases (e.g. 2018 Taisho patent filing).

Vadadustat (Vafseo) from Akebia Therapeutics is an oral hypoxia-inducible factor prolyl-4-hydroxylase domain (HIF-PHD) inhibitor developed for anemia in patients with chronic kidney disease (CKD). It received FDA approval on March 27th, 2024 for patients on dialysis for at least three months, after regulatory challenges including an earlier complete response letter due to safety concerns. This makes vadadustat the second FDA-approved HIF-PHD inhibitor for the treatment of anemia in CKD for dialysis-dependent patients after GSK’s daprodustat’s approval in Feb. 2023.