Ex-vivo studies confirmed higher efficacy of BTX-A51 on RUNX1 -mutated myeloblasts and demonstrate synergy with azacitidine and venetoclax. Although the overall efficacy was modest, this study lays the groundwork for future studies with improved patient selection and combination approaches.

Compound 3 exhibited an IC50 of 0.30 µM for CDK2 inhibition, making it five times less active than Roscovitine, which has an IC50 of 0.06 µM. However, compound 3 demonstrated slightly better inhibition of PIM1 compared to Staurosporine. These findings suggest that compound 3 is a promising anticancer agent with the potential for further development into a highly active compound.

Moreover, we highlight unanswered questions and propose key areas for future investigation. An advanced understanding of CDK7 will facilitate the pharmaceutical development of CDK7 inhibitors and help minimize undesirable adverse effects.

P2, N=60, Active, not recruiting, Carrick Therapeutics Limited | Recruiting --> Active, not recruiting

The three promising anti-proliferative hybrids (1a, 8a, 13a) were selected for the assessment of their in vitro inhibitory kinase activity against CDK2/GSK3β using roscovitine (IC50 = 0.88 μg mL-1) and CHIR-99021 (IC50 = 0.07 μg mL-1) as references, respectively...Moreover, it resulted in an increase in Bax and caspase-3 with a decrease in Bcl-2 levels in HepG2 cells compared with untreated cells. Finally, in silico drug likeness/ADME prediction for the three potent compounds as well as a molecular docking simulation study were conducted in order to explore the binding affinity and interactions in the binding site of each enzyme, which inspired their usage as anti-proliferative leads for further modification.

N-acetylcysteine (NAC), roscovitine and Mdivi-1 ameliorated SE-induced PV neuronal degeneration by mitigating CDK5 Y15 hyperphosphorylation, aberrant mitochondrial fragmentation and reduced GPx1-mediated NF-κB inhibition. Furthermore, SN50 (a NF-κB inhibitor) alleviated SE-induced PV neuronal degeneration, independent of dysregulation of mitochondrial fission, CDK5 hyperactivation and GPx1 downregulation. These findings provide an evidence that oxidative stress may activate CDK5-DRP1- and GPx1-NF-κB-mediated signaling pathways, which would be possible therapeutic targets for preservation of PV neurons in various diseases.

Additionally, 5g and 5i demonstrated 7.80-fold and 1.54-fold greater cytotoxicity against PA-1 and MCF-7, with IC50s of 1.08 µM and 3.54 µM, respectively, compared to seliciclib (8.43 µM and 5.46 µM)...Moreover, it triggered cell death by apoptosis and cell cycle arrest in G2/M. Taken together, 5g merits further investigation in PKPD research to discover a potential therapeutic candidate against cancer.

Treatment with roscovitine-a clinically applicable Cdk5 inhibitor-alone or combined with immune checkpoint inhibitors, significantly reduces BrM burden and increases tumour-infiltrating functional CD8+ lymphocytes in mice. Thus, astrocyte-induced Cdk5 overexpression endorses BrM immune evasion, whereas therapeutically targeting Cdk5 markedly improves the efficacy of immune checkpoint inhibitors and inhibits BrM growth.

No abstract available

P1/2, N=49, Active, not recruiting, Carrick Therapeutics Limited | Recruiting --> Active, not recruiting

Knockdown of CDK7 expression reduced Tax-mediated induction of target gene expression and cell cycle progression. These results suggest that the CDK7 gene is a crucial target of Tax-mediated trans-activation to promote cell proliferation by activating CDKs and transcription.

Starting from BTX-A51, a CK1α inhibitor that also targets CDK7 and CDK9, we designed and synthesized a series of 2,4-diaminopyrimidine derivatives as potent CDK7 inhibitors...Compound 22 effectively inhibited the phosphorylation of RNA polymerase II and CDK2 and resulted in G1/S phase cell cycle arrest and apoptosis in MV4-11 cells. It appears to be a promising lead compound for the development of a CDK7 inhibitor for cancer therapy.

This synergistic activity was also observed in Waldenström's Macroglobulinemia (WM) cells and with other inhibitors of E2F1 activity. Dual inhibition effectively impaired the MYC and E2F transcriptional programs and MM tumor growth and progression in xenograft animal models, providing evidence for combination therapy's potential as a therapeutic strategy in MM and WM.

Cimicifugin treatment led to the activation of the extrinsic apoptosis pathway and induced autophagy in T. annulata-infected cells. Furthermore, cimicifugin also inhibited the growth of P. falciparum, indicating that it has both anti-theilerial and anti-malarial activities and that TaCDK7 and PfCDK7 are promising drug targets.

Our study sheds light on how CDK7 and MDK influence irinotecan resistance in colorectal and highlights the potential of MDK-targeted therapies. We hypothesized that irinotecan sensitivity and overall treatment efficacy would improve by inhibiting MDK. This finding encourages a careful yet proactive investigation of MDK as a therapeutic target to enhance outcomes in colorectal cancer patients.

Additionally, compound JWZ-5-13 displayed bioavailability in a pharmacokinetic study conducted in mice. Therefore, JWZ-5-13 is a useful chemical probe to investigate the pharmacological consequences of CDK7 degradation.

Patients in low ASR group responded more actively to traditional chemotherapy drugs (Erlotinib and Roscovitine). CellChat analysis revealed that high ARS cell groups communicated with immune cells via SPP1 (ITGA4-ITGB1) and MK (MDK-NCl) signaling pathways. In this research, integrative analysis based on the ARS model provided a potential direction for improving the diagnosis and treatment of LUAD.

In this study, we first demonstrated that CDIP1 was upregulated after treatment with the anticancer drug adriamycin in human breast cancer MCF-7 cells but was degraded rapidly in the lysosomal pathway. We also demonstrated that treatment with the cyclin-dependent kinase 5 (CDK5) inhibitor roscovitine led to an increase in the electrophoretic mobility of CDIP1...Treatment of cells expressing CDIP1 with SAR405, an inhibitor of the class III phosphatidylinositol 3-kinase VPS34, caused a reduction in autophagy and promoted apoptosis. Therefore, autophagy is thought to be a defense mechanism against CDIP1 expression-induced apoptosis.

We propose a novel regulatory paradigm in which the activation of CDK7/CDK9-Rpb1 by nuclear proteostatic stress mediates transcriptional regulation to prime cancer cell paraptosis.

In addition, e-ATP-induced Caco-2 cell proliferation as well as cell survival were highly reduced in the presence of either PPADS or DHTS or selective CDK-2 inhibitor (Roscovitine) or selective Bcl-2 inhibitor (ABT-263). Furthermore, it was found that MMP-9 is critical for Caco-2 cells migration induced by e-ATP as demonstrated by a clear reduction in cells migration in the presence of a selective MMP-9 inhibitor (Marimastat). Collectively, these data demonstrate that ATP through P2R activation can induce HuR nucleocytoplasmic shuttling that could be translated into an increase in cancer-related genes expression and subsequent, cell proliferation and progression.

In-vitro cytotoxic activity of C. proximus extracts was examined against liver (HepG2), lung (A549), prostate (PC3), and bone (MG63) cell lines using MTT assay in comparison to doxorubicin. Di-N-octyl phthalate, 3-β-hydroxylean-11.13(18)-dien-30-oic acid methyl ester, elemol hydrocarbons, linoelaidic acid and linoleic acid demonstrated the lowest docking binding scores and similar binding modes against CDK2 as compared to that attained by the native ligand R-Roscovitine "CDK2 ATP inhibitor". Western blot analysis demonstrated that CDK2/cyclinA2 protein expression has been suppressed in A549 cell lines by Pet.Eth fraction.

P1, N=12, Not yet recruiting, Michael Wagner

P1, N=52, Terminated, Exelixis | N=373 --> 52 | Trial completion date: Oct 2024 --> May 2024 | Active, not recruiting --> Terminated; Business reasons

Roscovitine restored Rb expression and decreased the cell activity in zebrafish. HPV16 possesses a stronger carcinogenic ability than does HPV 58, and the mechanism underlying this effect may be the impairment of the E7-Rb pathway.

Coombes et al. Nature Comms 2023.

Activation of CDK7 is necessary for DOX-induced cardiomyocyte apoptosis and cardiomyopathy. Our findings uncover a novel proapoptotic role for CDK7 in cardiomyocytes. Moreover, this study suggests that inhibition of CDK7 attenuates DOX-induced cardiotoxicity, but augments the anticancer efficacy of DOX. Therefore, combined administration of CDK7 inhibitor and DOX may exhibit diminished cardiotoxicity but superior anticancer activity.

Furthermore, we synthesize the extant literature to provide a comprehensive overview of the advancement of CDK7-specific small-molecule inhibitors, encapsulating both preclinical and clinical findings in breast cancer contexts. The accumulated evidence substantiates the conceptualization of CDK7 as a propitious therapeutic target in breast cancer management.

At the same time, the transcriptional repression due to the degradation significantly reduced downstream gene expression of MYC, MDM2, BCL-2 and MCL-1, and reduced the inflammatory cytokine levels of TNF-α, IL-1β and IL-6 in PMBCs. These results indicate the beneficial impact of simultaneous CK1α and CDK7/9 degradation for acute myeloid leukemia therapy.

Further optimization generated compound 37 exhibiting good CDK7 inhibitory activity and high selectivity over other CDKs. This work clearly demonstrated macrocyclization is a versatile method to finely tune the selectivity profile of small molecules and MD simulation can be a valuable tool in prioritizing designs of the macrocycle.

Several potent small molecule inhibitors, exemplified by TG02 (4), have progressed to clinical trials...Our focus extends to various types of inhibitors, including pan-inhibitors, selective inhibitors, dual-target inhibitors, degraders, PPI inhibitors, and natural products. The discussion encompasses chemical structures, structure-activity relationships (SARs), biological activities, selectivity, and therapeutic potential, providing detailed insight into the diverse landscape of CDK9 inhibitors.

Remarkably, they demonstrated potent EGFR inhibition, with IC50 values of 0.026, 0.067, and 0.04 μM and inhibition percentages of 92.6%, 89.8%, and 91.2%, respectively, when compared to Erlotinib (IC50 = 0.03 μM, 95.4%). Furthermore, these compounds exhibited potent CDK-2 inhibition, with IC50 values of 0.301, 0.345, and 0.557 μM and inhibition percentages of 91.9%, 89.4%, and 88.7%, respectively, in contrast to Roscovitine (IC50 = 0.556 μM, 92.1%)...Treatment with 5g increased the gene expression of pro-apoptotic genes P53, Bax, caspases 3, 8, and 9 with notable fold changes while decreasing the expression of the anti-apoptotic gene Bcl-2. Molecular docking and dynamic simulations (100 ns simulation using AMBER22) were conducted to investigate the binding mode of the most potent candidates, namely, 5g, 5l, and 5n, within the active sites of EGFR and CDK-2.

In summary, the main experimental findings of this study are as follows: (1) the in vitro verification of CDK7 inhibition and selectivity that confirms the warhead covalent-binding principle (by CDK-specific kinase assays), (2) the highly pronounced antiviral efficacies of the hit compounds (in cultured cell-based infection models) with half-maximal effective concentrations that reach down to picomolar levels, (3) a particularly strong potency of compounds against strains and reporter-expressing recombinants of HCMV (using infection assays in primary human fibroblasts), (4) additional activity against further herpesviruses such as animal CMVs and VZV, (5) unique mechanistic properties that include an immediate block of HCMV replication directed early (determined by Western blot detection of viral marker proteins), (6) a substantial drug synergism in combination with MBV (measured by a Loewe additivity fixed-dose assay), and (7) a strong sensitivity of clinically relevant HCMV mutants carrying MBV or ganciclovir resistance markers. Combined, the data highlight the huge developmental potential of this host-directed antiviral targeting concept utilizing covalently binding CDK7 inhibitors.

Taken together, these findings support the clinical investigation of selective CDK7 inhibition combined with ET to overcome treatment resistance in ER+ BC. In addition, our study highlights the potential of increased MYC activity and intact P53 as predictors for sensitivity to CDK7 inhibitor-based treatments.

Compound 7e exhibited the most potent cytotoxic activity against A549 cell line (IC50: 0.155 µM) while compound 8d showed the most potent one against MCF7 cell line (IC50: 0.170 µM) in comparison with doxorubicin...Our findings by docking and experimental studies that compound 7e is a potent CDK2 inhibitor with IC50 of 0.149 µM, compared to the Roscovitine control drug with IC50 of 0.380 µM. We also found that compound 8d is a significant DHFR inhibitor with an IC50 of 0.199 µM, compared to Methotrexate control drug with IC50 of 0.131 µM. Evaluation of the antioxidant properties of ten compounds was also studied in comparison with Vitamin C. Compounds 1, 3, 6, 7c and 8e have higher antioxidant activity than Vitamin C which mean that these compounds can used as potent antioxidant drugs.

CDK7 inhibitors have emerged as a promising therapeutic strategy and have demonstrated significant anti-cancer activity in different subtypes of breast cancer, especially those that have been resistant to current therapies.

P1, N=373, Active, not recruiting, Exelixis | Recruiting --> Active, not recruiting

CDK5 might play important roles in bladder cancer progression and be a potential diagnostic and therapeutic target in the near future.

Concurrently, a combined JQ1 and THZ1 treatment abolished the transcription of oncogenes ETV4, MYC, NFE2L2. Our study suggested that BRD4 and CDK7 coupled can be a valuable biomarker in HCC diagnosis and the combination of JQ1 and THZ1 can be a promising therapeutic treatment against HCC.

TG02 exhibits overlapping toxicity with alkylating agents and low single agent clinical activity in recurrent glioblastoma. The role of CDK-9 and its down-stream effectors as prognostic factors and therapeutic targets in glioblastoma warrants further study.

P1/2, N=48, Recruiting, Carrick Therapeutics Limited | Phase classification: P1b/2 --> P1/2

P1/2, N=48, Recruiting, Carrick Therapeutics Limited

Subsequently, chronic long-term exposure to the clinically advanced HSP90i PU-H71 (Zelavespib) led to copy number gain and mutation (p.S164F) of the HSP90AA1 gene, and HSP90α overexpression. In contrast, acquired resistance toward other tested HSP90i (Tanespimycin and Coumermycin A1) was attained by MDR1 efflux pump overexpression. Remarkably, combined CDK7 and HSP90 inhibition display synergistic activity against therapy-resistant BCR-ABL1+ patient leukemia cells via blocking pro-survival HSR and HSP90α overexpression, providing a novel strategy to avoid the emergence of resistance against treatment with HSP90i alone.