AbbVie’s ABBV-467 is a highly potent, selective MCL-1 (myeloid cell leukemia-1) inhibitor which entered the clinic in 2022 in a Ph. I trial in patients with advanced hematologic cancers. MCL-1 has had a rough time in the clinic with multiple trials being halted or terminated due to cardiac toxicity, which is suspected to be an on-target effect. AbbVie’s approach with ABBV-467 was to target a highly potent/short half-life compound which could induce rapid apoptosis and tumor regressions in a short exposure period before the onset of any adverse events. Is this the end for MCL-1?

Chiesi Farmaceutici’s CHF-6523 is an inhaled, lung-restricted, selective PI3Kδ inhibitor designed to provide relief to patients with COPD. Its development involved optimization of permeability and solubility as well as identification of a solid form amenable for dry powder inhalation. Disclosed at the EFMC-ISMC 2024 joint conference in Rome, Italy, this article covers the structure, development, and early clinical data of CHF-6523, which ultimately indicates that PI3Kδ inhibition may not provide clinical effect in reduction of lung inflammation.

HRX-215 is an orally bioavailable MKK4 inhibitor for liver regeneration. In just over a decade since they discovered the dual specific kinase MKK4 as a master regulator of hepatocyte regeneration, HRX-215 completed a FIH clinical trial. This article is a fascinating case study on harnessing the liver's natural regenerative capacity, identifying key regulators of liver regeneration, and leveraging a kinase inhibitor with reported off-target activity for MKK4 as a suitable starting point, among other insights.

HiberCell recently disclosed the discovery of HC-7366, a potential first-in-class, intentionally discovered, orally bioavailable, potent, selective, small-molecule kinase activator of GCN2. HC-7366 has now progressed to Ph. I trials to treat ccRCC and AML. This case study is a fantastic example of how to mitigate CYP3A4 inhibition and improve oral bioavailability via judicious choice of salt formulation.

BridgeBio’s acoramidis (Attruby), an oral, second-generation stabilizer of the TTR protein, has been approved by the FDA for the treatment of ATTR-CM (transthyretin amyloid cardiomyopathy). Amyloid deposits in the heart muscle characterize the rare but potentially fatal disease. This case study reviews the history of TTR modulation, early experiments validating the therapeutic potential of TTR stabilization, the binding mechanism of acoramidis to TTR, the importance of binding enthalpy for differentiation, and the molecule’s impressive 30-month clinical data following an early scare.