AZD1332 and AZD7762 were more effective for patients in the low-risk group, whereas Entinostat, Nilotinib, Ruxolutinib, and Wnt.c59 were more effective for patients in the high-risk group. Knockdown of TYMS significantly inhibited the proliferation and invasive ability of ESCC cells in vitro. Overall, our MAR model provides stable and reliable results and may be used as a prognostic biomarker for personalized treatment of patients with ESCC.

Subsequent preclinical experiments demonstrated significant cytotoxicity of POLA1 silencing in combination with CHK1i in platinum-resistant HGSOC cell line models. Therefore, POLA1 expression may be predictive for CHK1i resistance, and the concurrent POLA1 inhibition may improve the efficacy of CHK1i monotherapy in this hard-to-treat population, deserving further investigation.

Through in silico screening of 2183 drug targets and 1646 compounds, we identified two targets (RRM2 and OPRD1) and eight agents (AZ960, carmustine, lasalocid, SGI-1776, AZD8055_1059, BPD.00008900_1998, MK.8776_2046, and XAV939_1268) with potential therapeutic implications for high-MRPScore patients. Indeed, a high MRPScore profile appears to elevate the risk of tumor progression and mortality, potentially through its influence on immune regulation. This suggests that the MRPS-related risk model holds promise as a prognostic predictor and may offer novel insights into personalized therapeutic strategies.

P1/2, N=229, Recruiting, Esperas Pharma Inc. | Phase classification: P1b/2a --> P1/2

P1, N=21, Active, not recruiting, St. Jude Children's Research Hospital

P2, N=24, Recruiting, Memorial Sloan Kettering Cancer Center | Trial completion date: Mar 2024 --> Mar 2025 | Trial primary completion date: Mar 2024 --> Mar 2025

Here we newly demonstrate that pharmacological inhibition of Chk1 using potent and selective inhibitor SCH900776, currently profiled in phase II clinical trials, significantly enhances cytotoxic effects of the combination of platinum-based drugs (cisplatin or LA-12) and TRAIL (tumor necrosis factor-related apoptosis inducing ligand) in human prostate cancer cells. The triple drug combination-induced cytotoxicity was partially enhanced by siRNA-mediated Mcl-1 silencing. Our findings suggest that targeting Chk1 may be used as an efficient strategy for sensitization of prostate cancer cells to killing action of platinum-based chemotherapeutic drugs and TRAIL.

Here, we demonstrate the utility of AP3 for the identification of a key druggable resistance mechanism to ACR-368 and how to overcome that with low dose gemcitabine (gem), providing OncoSignature negative patients with a new potential therapeutic option. These data supported a dose escalation Phase 1b/2 clinical study of low dose gem with ACR-368 to evaluate the efficacy and safety of the combination in ACR-368 OncoSignature negative patients (NCT05548296). This shows the potential of AP3 for unbiased elucidation of actionable drug resistance mechanisms and rapid clinical implementation in our trials, which have recently confirmed clinical activity.

P1, N=150, Recruiting, Boundless Bio | Phase classification: P1/2 --> P1 | N=47 --> 150 | Trial completion date: Jan 2026 --> Sep 2027 | Trial primary completion date: Jan 2025 --> Sep 2026

The upregulation of lncRNA AFAP1-AS1, which increases TSCC cell viability, migration, proliferation and invasion via the AFAP1-AS1/miR-133a-5p/ZIC2 axis, aids in the progression of TSCC.

Mechanistically, SRA737 synergized with AZD1775 by blocking AZD1775-induced feedback activation of CHK1 in prostate cancer cells, resulting in increased mitotic entry and accumulation of DNA damage. In summary, this preclinical study shows that CHK1 inhibitor SRA737 alone and its combination with AZD1775 offer potential effective treatments for CRPC and NEPC.

Importantly, targeted inhibition of the check-point inhibitor CHK1 with MK-8776 effectively caused death of p21-high T47D cells, thus establishing a new vulnerability of BYL719-resistant breast cancer cells. Together, our integrated studies uncover hidden molecular mediators causing resistance to PI3Kα inhibition and provide a framework to prioritize combination therapies for PI3K-mutant breast cancer.

Also, greater anti-proliferative and cell killing effects were noted in the TP53 MUT cells than in the TP53 WT cells. This study's data suggests that P53 status/functioning is a key factor in determining the sensitivity of NSCLC and CRC cancer cells towards CHK1 inhibition, even in circumstances conducive to high replicative stress.

"Acrivon Therapeutics, Inc...announced the U.S. Food and Drug Administration (FDA) has granted Breakthrough Device designation for the ACR-368 OncoSignature assay, a multiplex immunofluorescence assay for the identification of ovarian cancer patients who may benefit from ACR-368 treatment. The designation reflects FDA’s determination that the device is reasonably expected to provide for more effective treatment or diagnosis of life-threatening or irreversibly debilitating human disease or conditions."

P1/2, N=390, Recruiting, Acrivon Therapeutics | Phase classification: P1b/2 --> P1/2

In conclusion, we developed a precise gene editing strategy of human HSCs to identify prexasertib as a promising therapy for SF3B1m myeloid neoplasms, and implicate the mitotic function of CHK1 as a SF3B1m sensitivity. The safety and toxicity profiles displayed in early phase clinical trials make prexasertib a suitable agent for further clinical investigation in SF3B1m MDS and its advanced stages.

Combination of STP-B with pharmacological inhibitors of key components of the DDR pathway (ATR, CHEK1 or WEE1) resulted in synergistic growth inhibition and early apoptosis. Taken together, these findings identify CTPS1 as a promising new target in MM, either alone or in combination with DDR pathway inhibition.

Mice were intraperitoneally injected with 25 mg/kg CHK1 inhibitor AZD7762 and 20 mg/kg gemcitabine for 3 weeks. Further hiPSC-CMs and mice experiments demonstrated that SIRT3 overexpression maintained mitochondrial function while alleviating CM pyroptosis, and thereby improving mice cardiac function. In summary, our results suggest that targeting SIRT3 could represent a novel therapeutic approach for clinical prevention and treatment of cardiotoxicity induced by CHK1 inhibition and gemcitabine.

P1/2, N=21, Active, not recruiting, Memorial Sloan Kettering Cancer Center | Trial completion date: Sep 2023 --> Sep 2024 | Trial primary completion date: Sep 2023 --> Sep 2024

This subtype tended to metastasize and was resistant to respond to immunotherapy. Pharmacogenomics analysis showed three therapeutic agents (NVP-BEZ235, LY2606368, and rutin) were potential interventions for MNG-4.

No abstracts available

No abstracts available

P2, N=10, Completed, Baylor Research Institute | Active, not recruiting --> Completed | Trial completion date: Dec 2023 --> Nov 2022

The cytotoxicity of curcumin against CD44 cells (IC 40.30±2.32 μM) was found to be greater than that against CD44 cells (IC 83.31±2.91 μM)...Our findings indicate that curcumin, by promoting the expression of tumor suppressors, miR-383-5p and miR-708-5p, and inhibiting their target genes, induced its cytotoxicity against CD44 PC cells. We trust that curcumin could be established as a promising adjuvant therapy to current PC treatment options following more research in clinical settings.

Melanoma cell lines resistant to BRAF inhibitor (BRAFi) or immune checkpoint inhibitors (ICI) retain their sensitivity to CHK1i + LDHU, with sensitivity similar to that of parental tumours. In vivo, BRAFi-resistant and BRAFi-sensitive parental tumours produce an identical immune response with treatment.

Collectively, our results suggest RRM2 is a promising therapeutic target for GBM, and targeting RRM2 with triapine sensitizes GBM cells to radiation and independently induces synthetic lethality of GBM cells with CHK1 inhibition. Our findings suggest combining triapine with radiation or rabusertib may improve therapeutic outcomes in GBM.

The current treatment approach for APL involves differentiation therapy using all-trans retinoic acid (ATRA) and arsenic trioxide (ATO). Overall, the ability of MK-8776 to induce PML-RARα degradation and stimulate differentiation of immature APL cancer cells into more mature forms recapitulates the concept of differentiation therapy. Considering the in vivo tolerability of MK-8776, it will be relevant to evaluate its potential clinical benefit in APL patients resistant to standard ATRA/ATO therapy, as well as in patients with other forms of acute leukemias.

Conclusions The first ecDNA directed therapy, BBI-355, demonstrated significant anti-tumor activity as a single agent and in combination with targeted therapies in multiple ecDNA+ oncogene amplified tumor models. Clinical testing in patients with oncogene amplification is ongoing.

P1b, N=32, Recruiting, PharmaEngine | Not yet recruiting --> Recruiting | Initiation date: Mar 2023 --> Jul 2023

Different TNBC cell lines were treated with AURKA inhibitor (AURKAi, MLN8237) and CHK1i (CHK1i, MK8776). Additionally, dual inhibition of AURKA and CHK1 synergistically enhanced radiosensitivity in MDA-MB-231 xenografts. Moreover, we detected that both CHEK1 and AURKA were overexpressed in TNBC patients and negatively correlated with patients' survival Our findings suggested that AURKAi in combination with CHK1i enhanced TNBC radiosensitivity in preclinical models, potentially providing a novel strategy of precision treatment for patients with TNBC.

SRA737 was well tolerated at doses that achieved preclinically relevant drug concentrations but single agent activity did not warrant further development as monotherapy. Given its mechanism of action resulting in abrogating DNA damage repair, further clinical development of SRA737 should be as combination therapy.

Using high-throughput drug screens, we identified ataxia telangiectasia and rad3-related protein/checkpoint kinase 1 (CHK1) pathway inhibitors as cytotoxic and further validated the activity of the CHK1 inhibitor (CHK1i) prexasertib in PARPi-sensitive and -resistant BRCA-mutant HGSC cells and xenograft mouse models...BRCA reversion mutation in previously PARPi-treated BRCA-mutant patients was not associated with resistance to CHK1i. Our findings suggest that replication fork-related genes should be further evaluated as biomarkers for CHK1i sensitivity in patients with BRCA-mutant HGSC.

Combining olaparib with ATR/CHK1 inhibitors increases its effectiveness and may be a new opportunity for more effective ovarian cancer therapy.Material and MethodsWe examined efficacy of PARPi in combination with DNA damage response pathway proteins inhibitors - ATR (AZD6738, ATRi) and CHK1(MK8776, CHK1i) kinases in BRCAMUT (PEO-1) and BRCAWT (SKOV-3 and OV-90) cells. ATR and CHK1 inhibitors provoke premature mitotic entry, leading to genomic instability and ultimately cell death. This research was funded by the National Science Centre, Poland, grant number: Sonata Bis 2019/34/E/NZ7/00056.

Together, our results provide novel insights into the mechanistic link between A3B and R-loops in the promotion of RS in cancer. This will inform the development of markers to predict the response of patients to ATRi/Chk1i.

Collectively, our data suggest the possible involvement of innate immunity in modulating CHK1i response. Increasing peripheral immunosuppressive cells and lower immunocompetence of the innate immune system may contribute to CHK1i resistance, whereas the functionality of DCs may be involved in the response. Enhancing innate immunity may represent a strategy to increase CHK1i response in this hard-to-treat population.

These data provide evidence that betulinic acid is a potential candidate for chemosensitization as a naturally occurring Chk1 inhibitor and warrants further preclinical evaluation.

P2, N=10, Active, not recruiting, Baylor Research Institute | Trial completion date: Dec 2022 --> Dec 2023

Our results suggest that the mitochondrial-related risk model could be a reliable prognostic biomarker for personalized treatment of STAD patients.