Dennis C. Koester

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.

BMS-986408 is an oral, dual DGK ⍺ and ζ inhibitor currently in a Ph. I/II trial in patients with solid tumors. The compound was identified stemming from a phenotypic screening approach, and subsequent target deconvolution revealed DGK to be the target. If approved, it would be a first-in-class intracellular checkpoint inhibitor of DGK. This is an excellent case study on how to overcome a DILI risk associated with BSEP inhibition, as well as how to improve solubility and PK properties of your compounds through the introduction of polarity, reduction of aromatic rings, and increase in f(sp3).

KEAP1 inhibition/NRF2 activation has been hotly pursued in recent years for immunology indications; however, in oncology, NRF2 degradation has been posited as a novel therapeutic mechanism for specific cancers. Vividion has already disclosed work on covalent KEAP1 inhibitors, but at the recent ACS Fall 2024 meeting, the structure and discovery story of their clinical oral covalent activator of KEAP1 were disclosed, identified through careful analysis of the data from their inhibitor screen.

During Drug Hunter’s Flash Talks, experts talk in-depth about hot topics in drug discovery. These experts also share insights beyond the subjects of their presentations, such as how they got inspired to become a drug hunter, what their favorite molecule is, what excites them most in drug discovery today, and what advice they wish they could give their younger selves. Here is a quick look at some of these insightful nuggets from Flash Talks hosted between January and August 2024.

The recently released WHO INN proposed names list includes the structure and name of Structure Therapeutics’ oral small molecule GLP-1R agonist, aleniglipron (GSBR-1290). Seemingly emerging from a “fast-follower” program based on Chugai/Eli Lilly’s orforglipron, the compound includes an unusual phosphine oxide motif and has shown positive results on plasma glucose levels and bodyweight in a Ph. IIa study.

The INN Proposed List 131, released on August 11th, 2024, unveils the latest batch of drug names currently under consideration by the WHO. To streamline your review, we’ve distilled and compiled a searchable table for the small molecules that includes company identifiers, the newly proposed drug names, structural information, original patents, companies, and mechanisms of action, including structures that were previously undisclosed.

AstraZeneca recently disclosed the structure and discovery journey of their oral small molecule PCSK9 inhibitor, AZD0780, during the ACS Fall 2024 First Time Disclosures session in Denver. Discover how the team identified a fragment hit targeting a previously unexplored pocket, verified its novel mechanism of action, and successfully advanced it into a clinical compound now in Ph. II trials for patients with dyslipidemia.

In this article, you'll find a curated selection of nearly 50 molecules from July that piqued our interest, highlights of some of our favorites, and explanations of why they're worth watching.

BMS-986365 is a potential best-in-class heterobifunctional ligand-directed degrader of WT AR. This full case study details how this heterobifunctional degrader was engineered to have low intrinsic agonism and exert direct antagonism of WT AR through occupancy of its ligand-binding domain, how the dual modality of BMS-986365 results in deep AR pathway inhibition and allows antagonism to reinforce degradation to combat compensatory resistance mechanisms, its attractive preclinical profile, interim clinical data, how it differentiates from Arvinas’ first-to-clinic AR degraders, and more!

DILI is a leading cause of acute liver failure, accounting for half of these cases and often resulting in drug withdrawals. Understanding and managing DILI risk as a medicinal chemist involves exploring the intricate interplay among properties and structural features. In this article, we provide a medicinal chemist's perspective on the current understanding of DILI mechanisms, highlight cutting-edge assay developments for a holistic assessment, and discuss strategies for predicting DILI risks.

Novartis’ HRO761 is an oral allosteric WRN helicase inhibitor, aimed at treating MSI-high and dMMR tumors. This article details the discovery of HRO761 and highlights the importance of selecting appropriate assays during early HTS as well as transferable medicinal chemistry strategies to optimize permeability and solubility through the modulation of LipE, neutral TPSA, chameleonicity, and non-classical zwitterions. It also explores the X-ray structure of HRO761 bound to WRN, how it differentiates from Vividion's VVD-214, its preclinical activity, clinical status, chemical synthesis, and more!

In June, we saw several FDA approvals for treatments targeting primary biliary cholangitis and COPD. The industry witnessed multibillion- and multimillion-dollar deals across various therapeutic areas. Advances were made in obesity therapeutics, with novel targets and clinical readouts for GLP-1 agonists and NLRP3 inhibitors. Alkermes and Takeda reported results for OX2R agonists in narcolepsy, while an antimalarial drug showed promise in PCOS. Despite these advancements, there were clinical trial failures for key molecules. Here's a recap of the most notable news highlights from June 2024!

To help you quickly scan the patent literature, we’ve distilled down thousands of new documents into a searchable table of over 200 selected patents focused on key areas in drug discovery, all published in May 2024. This resource is enriched with detailed highlights on selected molecules targeting high-interest areas such as STING antagonists, WIZ degraders, RNA degraders, and macrocyclic amine-based OX2R modulators.

PRMT5 is an epigenetic “synthetic lethality” target that has attracted much attention among drug hunters. The first generation of PRMT5 inhibitors was limited by systemic toxicities resulting in a cooling of industry interest, until the recent identification of tumor-specific inhibitors. These second-generation compounds target the MTA:PRMT5 complex in MTAP-deleted cancers—15% of all tumors—leading to a revival of the target. Read on to find out which companies are prevailing in the search for a first-in-class PRMT5 inhibitor and how their clinical compounds differentiate.

SGR-1505, the first in-house clinical compound developed at Schrödinger, is an oral, allosteric MALT1 inhibitor currently in the clinic for the treatment of mature B cell malignancies. The discovery effort, disclosed at the ACS Spring 2024 meeting, was completed in an impressive 10 months, starting from a published scaffold. SGR-1505 demonstrated preclinical single-agent and combination activity as well as inducing resensitization in BTK and BCL-2 inhibitor-resistant tumors. The compound is currently progressing in a Ph. I trial in patients with mature B cell malignancies.

TNG462, developed by Tango Therapeutics, is a potential best-in-class, oral, protein arginine methyltransferase 5 (PRMT5) inhibitor currently in Ph. I/II clinical trial for MTAP-deleted solid tumors. TNG462 is designed to cooperatively bind to PRMT5 when complexed with its endogenous inhibitor methylthioadenosine (MTA), which accumulates in MTAP-deleted tumors. This triggers synthetic lethality in cells with an MTAP-deletion and spares healthy tissues with low MTA levels. A CNS-permeable analogue, TNG908, is also entering clinical trials for MTAP-deleted glioblastoma.

VVD-214/RO7589831 is an oral covalent, reversible, and allosteric inhibitor of WRN helicase discovered by the San Diego-based biotech Vividion Therapeutics and being developed by Roche for tumors marked by microsatellite instability and/or mismatch repair deficiency. Vividion has utilized its chemoproteomics platform to discover and develop novel treatment options for oncology targets. The structure and initial preclinical pharmacology data for VVD-214 were recently disclosed at the AACR Annual Meeting 2024 in San Diego. VVD-214 is currently being evaluated in a Ph. I trial.

Peptidic GLP-1R agonists have received significant media coverage over the past year for their astounding efficacy in several indications. While most of the recent fanfare has been related to their role in weight loss, GLP-1R agonists have been a mainstay of the type 2 diabetes treatment landscape for the past 2 decades. GLP-1R agonists have also recently shown efficacy in reducing heart disease risk and treating certain chronic kidney diseases. Here’s a recap of the March 14th, 2024, Flash Talk, from Oliver Philps.

Minipigs have recently gained prominence as an alternative non-rodent in vivo model for pharmacokinetic (PK), efficacy, and toxicology studies supporting human dose predictions. This article provides an overview of the use of minipigs in small molecule preclinical drug discovery research, tracing their historical background and outlining practical considerations for selecting them in studies focusing on hepatic metabolism, oral bioavailability, CNS penetration, and toxicology. It highlights minipigs' unique advantages and makes a compelling case for their continued use in preclinical research.

February 2024 saw numerous notable patent disclosures aimed at a variety of therapeutic targets across different disease areas. The Drug Hunter team has compiled a searchable table that includes more than 200 patents of relevance to the drug discovery industry. Accompanying the table are detailed notes, as well as standout features from some of our top picks, including MTA-cooperative PRMT5 inhibitors, heterobifunctional TYK2 degraders, strategies for engaging and reactivating mutant p53, and more.

Nrf2/KEAP1 modulation has been pursued since the discovery that dimethyl fumarate and its metabolite protect CNS neurons via up-regulation of Nrf2-depdendent activities. Compounds with greater selectivity have been sought for many years, culminating with the approval of the KEAP1 inhibitor, omaveloxolone. Vividion disclosed their efforts to identify the covalent KEAP1 inhibitor, VVD-702. This ACS Spring 2024 disclosure is an excellent case study for covalent hit finding using chemoproteomics, covalent compound optimization, and the use of an uncommon but surprisingly stable covalent warhead.

With increasingly tight timelines between bench and clinic, considering formulation strategies early on can give your program a competitive edge. This succinct formulations guide provides specific clinically-used examples of common formulations, and can help you select a formulation strategy most likely to succeed based on the properties of your compound.

The impact of small and mid-sized biotech companies has become increasingly important. The shift from large pharma dominance to a biotech-driven era of drug discovery presents challenges to the traditional model of education for emerging medicinal chemists. Industry leader Dean Brown recently highlighted challenges for modern medicinal chemists starting in biotech who face fewer mentoring opportunities and are often propelled into leadership positions sooner than their counterparts in big pharma. Here we share how our team of former industry scientists at Drug Hunter can help.

PF-07817883 (ibuzatrelvir) is an oral, second-generation SARS-CoV-2 M^pro inhibitor developed by Pfizer. These efforts follow the success of Pfizer's antiviral combination drug, Paxlovid, which was granted Emergency Use Authorization by the FDA for the treatment of COVID-19. PF-07817883 was granted Fast Track designation and recently completed a Ph. II clinical trial in outpatient adults with COVID-19 symptoms. This article details the discovery strategy for PF-07817883, which includes addressing metabolic soft spots identified through MetID studies, recent clinical developments, and more.

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.

Obtaining adequate drug exposure in the brain is key to treating CNS diseases effectively. Recently, Dennis Koester gave us a crash course in CNS drug discovery in a Drug Hunter Flash Talk. Here, he sums up some key points on how to find compounds that cross the blood-brain barrier.

M4205 (IDRX-42) is a highly selective type II receptor tyrosine kinase inhibitor of KIT, discovered by Merck KGaA and currently being developed by IDRx. The molecule is a notable example of kinase selectivity achieved with a non-classical hinge binder. M4205 (IDRX-42) has received an Orphan Drug designation and is currently being evaluated in a Ph. I/Ib FIH trial for GIST, one of the most common mesenchymal neoplasms in the GI tract.

Bexotegrast is a dual-selective αvβ6-αvβ1 integrin inhibitor with surprising efficacy and safety data from a Ph. II trial in idiopathic pulmonary fibrosis (IPF). The αv integrins have been studied for decades in indications such as cancer and IPF. Both small molecule and antibody-based integrin inhibitors have demonstrated preclinical toxicities in non-human primates. This article highlights the unmet need for effective therapies for IPF and related conditions, a comparison of bexotegrast with other integrin binders, and possible reasons why bexotegrast is different in terms of safety.

“Compound 25” is a selective, CNS-penetrant, ATP-competitive LRRK2 inhibitor that entered preclinical candidate enabling studies but was discontinued for undisclosed reasons. The molecule possesses two interesting chemical features: a “bow-tie” spirocyclopropyl group that made a significant impact on potency and overall properties [...]

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.

“Compound 3” (UCSF) is a covalent KRAS G12R inhibitor used as a proof-of-concept for covalent arginine modification. KRAS is the first oncoprotein to be identified and is a well-known cancer-driving protein. As one of the most frequently mutated proteins in pancreatic and colorectal cancers, residues that are frequently mutated are [...]

In this highlight, Dr. Dennis C. Koester reviews treatment options for HIV and explains how small molecule long-acting injectables (LAIs) are offering significant promise in both HIV treatment and prophylaxis. A Coming Paradigm Shift for HIV Treatment and Prophylaxis By Dennis C. Koester The surge of the coronavirus pandemic has made our [...]

INE963 (Novartis Institute for Tropical Diseases) is an oral, single dose, fast-acting blood-stage antimalarial candidate . The molecule was identified using a phenotypic high-throughput screening approach which has been successfully used to identify new antimalarial chemotypes . Phenotypic screens can be preferable to target-based [...]

One of the privileges that have come with building Drug Hunter has been all the insightful thoughts and commentary our readers share. We also appreciate how readers help catch mistakes and offer corrections. This new series of “ Drug Hunter Letters” highlights recent insightful communications from drug hunters, which includes this time: Dr [...]

We asked the global drug discovery community to nominate and vote on their favorite molecule from 2021, and the results are in. The 2021 choice for Drug Hunter’s Small Molecule of the Year is Pfizer’s CoV-2 M pro Inhibitor, PF-07321332 (nirmatrelvir, Paxlovid) . Published in a November 2021 Science article , the molecule was praised for its [...]