Kerry Betz

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.

BridgeBio’s BBO-8520 is a selective, covalent KRAS(G12C) inhibitor which differentiates itself from the pack by engaging the (ON) state of the protein, potentially conferring increased clinical benefit in KRAS(G12C)-driven cancers, including overcoming resistance to current treatments. Disclosed at the 2024 AACR Annual Meeting in San Diego, is currently in a Ph. I trial in patients with advanced non-small-cell lung cancer. This article covers the structure, mechanism of action and preclinical efficacy that marks this compound out as one to watch.

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?

Pfizer’s oral, CDK4-selective inhibitor PF-07220060 has the potential to revolutionize treatment of HR+/HER2- breast cancer through avoiding the neutropenia DLTs associated with SoC CDK4/6 drugs and permitting greater coverage of the desired CDK4 target. Our full article outlines data presented at AACR 2024, covering the molecule’s course from in silico-informed screen, through structurally enabled optimization against CDK6 and GSK-3β to promising preclinical profile. Fresh clinical data showed efficacy and tolerability supporting PF-07220060's clinical progression.

AstraZeneca has joined the race to gain approval for a first-in-class, orally bioavailable selective inhibitor of CDK2 with AZD8421, which was recently disclosed at the AACR San Diego 2024 “New Drugs on the Horizon” series. CDK2-selective inhibitors are a hot area right now, with their promise to overcome the resistance against approved CDK4/6 inhibitors. Read the full case study to learn about the CDK2-selective competitive landscape, the structural and kinetic data which underpin AZD8421’s CDK-selectivity and the preclinical activity data which has propelled it into the clinic.

BLU-222 is a potential first-in-class, orally bioavailable selective inhibitor of CDK2 discovered and currently in development by Blueprint Medicines for the treatment of advanced solid tumors. Read the full case study to learn about the competitive landscape of CDK inhibitors, the discovery story enabled by the DiscoveRx KINOMEscan screening platform, how exquisite kinome selectivity can be achieved despite ~100% active site sequence similarity between CDK1/2, how this molecule can potentially treat CCNE1-amplified and CDK4/6i-resistant tumor models, interim clinical data, and more.

ORIC-533, a potential best-in-class oral inhibitor of CD73 from ORIC Pharmaceuticals, is currently in a Ph. Ib trial for relapsed/refractory multiple myeloma (MM). It inhibits the CD73-mediated conversion of AMP to adenosine which generates an immunosuppressive tumor microenvironment and has the potential to be a next-generation immunotherapy. The in-depth use of X-ray structures led the team to discover a novel set of phosphonate bioisosteres which acheived bioavailability in a polar scaffold. The structure and discovery of ORIC-533 were recently disclosed at the ACS Spring 2024 Meeting.

Vertex’s VX-548 is a potential first-in-class, exquisitely selective, oral NaV1.8 inhibitor that recently captured headlines for its positive Ph. III data. With the ongoing opioid epidemic throughout the US, there is an urgent unmet medical need for non-addictive pain medications as alternatives to opioids. They plan to file an NDA by mid-2024 for the treatment of moderate-to-severe acute pain. This case study highlights what’s publicly known about Vertex’s journey in pain leading up to the Ph. III readout for VX-548, and why this is such a watershed moment for pain management.

PF-9363 (CTx-648) is a first-in-class, oral inhibitor of the KAT6A/B histone lysine acetyltransferases (HATs) for the treatment of ER+/luminal & KAT6A+ breast cancer discovered by Melbourne’s Cancer Therapeutics CRC (CTxT) and Pfizer, San Diego. This article discusses why the molecule is scientifically notable in drug discovery for epigenetic targets and transferable scientific insights from its decade-long KAT6 campaign including its target rationale, hit-finding and lead optimization, synthesis and relevant clinical data.

LUNA18 is an orally bioavailable, cell-penetrant, macrocyclic peptide pan-RAS inhibitor (Chugai ’21Q3 earnings call) intended for the treatment of KRAS-mutant cancers. It disrupts the protein-protein interaction between KRAS and SOS, preventing RAS activation.

AZD4747 is a CNS-penetrant, oral KRAS G12C covalent inhibitor for the treatment of CNS-metastatic KRAS-mutant cancers. KRAS inhibitors have tended to be quite large and fall outside the range of physicochemical properties generally required for CNS permeability. (MW < 360 Da, cLogD < 2, TPSA < 90 Å2. AZD4747 is much smaller than marketed KRAS G12C inhibitors but maintains exceptional cellular potency. The team also encountered an unexpected toxicity that scientists working on covalents should pay attention to.