padnarsertib (KPT-9274)

KPT-9274, a PAK4 inhibitor, significantly reduces the growth of triple-negative breast cancer cells and mammary tumors in mouse models, and it also inhibits the growth of several other types of cancer cells...Molecular docking studies were also used to help us better understand the mechanism by which PAK4 inhibitors block PAK4 and NAMPT activity, and we identified specific residues on the PAK4 inhibitors that interact with NAMPT and PAK4. Our results suggest that PAK4 inhibitors may have a more complex mechanism of action than previously understood, necessitating further exploration of how they influence cancer cell growth.

P1, N=20, Terminated, Antengene Therapeutics Limited | N=70 --> 20 | Recruiting --> Terminated; Because the sponsor modified the study-product development strategy.

NAMPT inhibition (alone or in combination with other cancer therapies, including endocrine therapy and chemotherapy) results in decreased cell viability and tumor burden for many cancer types. Many NAMPT inhibitors (NAMPTi) tested before were discontinued due to toxicity; however, a novel NAMPTi, KPT-9274, is a promising, low-toxicity option currently in clinical trials.

Moreover, the compound reduced PAK4 activity by altering its mostly cytoplasmic localization, leading to NAD+-dependent decreases in phosphorylation of S6 Ribosomal protein, AKT, and β-Catenin in the cytoplasm. These findings suggest that KPT-9274 could be a promising treatment for ovarian cancer patients who are resistant to platinum drugs, emphasizing the need for precision medicine to identify the specific NAD+ producing pathway that a tumor relies upon before treatment.

Furthermore, the combination of the BCL2 inhibitor venetoclax and the NAMPT inhibitor KPT-9274 resulted in the death of significantly more leukemic blasts in AML samples with -7/-7q compared to the NAMPT inhibitor alone. In conclusion, our findings demonstrate that AML with -7/-7q are highly sensitive to NAMPT inhibition, suggesting that NAMPT inhibitors have the potential to be an effective targeted therapy for patients with monosomy 7 or del(7q).

KRASG12C inhibitors, such as sotorasib and adagrasib, have revolutionized cancer treatment for patients with KRASG12C-mutant tumors. Moreover, the combination of KPT9274 and sotorasib enhances survival. In conclusion, this is the first study to demonstrate that KRASG12C inhibitors can synergize with the PAK4 inhibitor KPT9274 and combining KRASG12C inhibitors with KPT9274 can lead to remarkably enhanced antitumor activity and survival benefits, providing a novel combination therapy for cancer patients who do not respond or develop resistance to KRASG12C inhibitor treatment.

In contrast, high mtDNAcn was not a predictive survival marker in a cohort of adult AML patients treated with venetoclax (VEN) + hypomethylating agents (HMA), indicating that these metabolic features are specifically linked to the resistance to intensive chemotherapy...Due to the link between mtDNAcn and mt complex I activity, we investigated if the treatment with metformin, known to inhibit complex I, would sensitize AML patients with high mtDNAcn to the standard of care AML drugs, such as Cytarabine (AraC), FLT3-inhibitors and VEN...Concomitantly, OXPHOS and glycolysis were diminished upon KPT-9274+metformin, suggesting that the combination was able to bypass the metabolic rewiring of the AML cells. In conclusion, we uncover a subgroup of patients with high mtDNAcn linked to increased mtOXPHOS that is resistant to chemotherapy-induced apoptosis and is characterized by poor clinical outcomes, which can be overcome by the inhibition of the mt complex I. Moreover, the quantification of mtDNAcn can be easily incorporated into clinical practice as a simple and cost-effective metabolic readout of AML patients to identify metabolic vulnerabilities.

PAK4 inhibition by KPT-9274 led to significant potentiation of Gemcitabine activity in PDAC cells, with an increase in apoptosis, DNA damage and cell cycle arrest. Our data unravel probable molecular mechanisms behind combination of PAK4 inhibition with Gemcitabine to counter PDAC, which may be unequivocally proved further with knock down of PAK4. Our findings provide a strong rationale to exploit the combination therapy of Gemcitabine and PAK4 inhibitor for PDAC at pre-clinical and clinical levels.

The dogs in this study were part of a larger clinical trial evaluating the use of combinations of doxorubicin chemotherapy, anti-CD20 monoclonal antibody, and one of three small molecule inhibitors: KPT-9274, TAK-981, or RV1001. Trends for selected candidate biomarker genes were confirmed via qPCR. Our findings emphasize the heterogeneity in DLBCL, similarities and differences between canine and human DLBCL, and ultimately identify biomarkers that may help guide the choice of chemoimmunotherapy treatment in dogs.

In this study, we identified nicotinamide phosphoribosyltransferase (NAMPT), an important enzyme in nicotinamide adenine dinucleotide (NAD+) metabolism, to be increased in metastatic breast cancer (MBC) cells treated with fulvestrant (Fulv)...A synergistic effect was not observed when KPT-9274 was combined with palbociclib or tamoxifen or when Fulv was combined with other metabolic inhibitors...Targeting metabolic adaptations in endocrine-resistant metastatic breast cancer is a novel strategy, and alternative approaches aimed at improving the therapeutic response of metastatic ER+ tumors are needed. Our findings uncover the role of ERα-NAMPT cross-talk in metastatic breast cancer and the utility of NAMPT inhibition and antiestrogen combination therapy in reducing tumor burden and metastasis, potentially leading to new avenues of metastatic breast cancer treatment.

Previous in vitro work on determining the unique sensitivities of various cancers to nicotinamide phosphoribosyltransferase inhibitors (NAMPTis) has demonstrated promising effects of treating cancer cells with NAMPTis such as FK866 and KPT9274. In addition to a synergistic growth inhibitory response in ovarian cancer cells, preclinical combination studies of NAMPTis with olaparib, an approved PARP inhibitor, exhibited higher levels of DNA damage accumulation than with single drug treatments. Our in vitro and in vivo characterizations of NAMPT inhibition suggest that NAMPTis as either single agents or in combination treatments with PARP inhibitors should be investigated further as potential treatment options for ovarian cancer patient populations.

We identified that conventional drugs such as cytarabine and venetoclax had significant cytotoxic effects on AML blasts, albeit with heterogeneous efficacies dependent on AML subtype, while M2 macrophages remained largely unaffected. In conclusion, our screening setup allows for the identification of compounds that can target both leukemic blasts as well as their tumor supportive microenvironment, and thiostrepton, KPT-9274 and metformin emerged as potentially promising candidates. We hope that (combinatorial) targeted drug treatments that also take the tumor microenvironment into account can help to improve AML treatment and prevent relapse.

Ex vivo studies revealed that while conventional chemotherapeutics, AraC/venetoclax, efficiently target the AML blasts (CD34+/CD117+) with minimum effects on the AdMs, NAMPT inhibition with KPT-9274 was able to efficiently target both the AML blasts and the AdM fractions. Functionally, treatment of M2 macrophages with KPT-9274 shifted their polarization towards an M1 phenotype, with reduced support to AML cells in co-culture assays. In conclusion, we uncover the heterogeneity in the macrophage landscape in AML patients, show the functional relevance of M2-polarized macrophages for leukemic transformation, and provide alternative approaches for targeting aimed at the tumor-supportive microenvironment.

PAK4 inhibitors PF-3758309 (PF) and KPT-9274 (KPT) were evaluated in murine models. A combination of KPT and αPD1 significantly reduced tumor growth when compared to WT (P<.01) and WT αPD1 (P<.01). In conclusion, PAK4 inhibition increased immune infiltration and improved αPD1 treatment response in preclinical mouse prostate cancer models.

In order to determine the efficacy of NAMPT inhibitors in different cancer cells, we performed proliferation assays on a large and fully characterized panel of human cancer cell lines (n=496) for response to several NAMPT inhibitors including FK866, KPT9274 and LSN3154567. Furthermore, the molecular predictors of response identified in our screen may ultimately be useful in developing diagnostic tools for enrollment in biomarker-enriched clinical trials aimed at determining the potential use of NAMPT inhibitors. These results suggest the inhibitors’ therapeutic potential in patient populations presenting with AML, ovarian cancer, Ewing’s sarcoma and SCLC all of which currently have high unmet needs.

This study, using various preclinical experimental models, demonstrates the therapeutic potential of targeting PAK4-NAMPT in DLBCL, FL, and MCL. The orally bioavailable, safe, and efficacious PAK4-NAMPT dual inhibitor KPT-9274 warrants further clinical investigation.

Similar results were obtained with positive controls PAK4 [PF-3578309] and NAMPT specific inhibitors [FK-866]...We then showed KPT-9274 to synergize with the standard of care chemotherapy cyclophosphamide, vincristine, and adriamycin used for NHL management (decreased IC25 and IC50 in several combination treatments)...The anti-tumor potential of KPT-9274 ± niacin in several aggressive lymphoma models strongly supports its efficacy in this setting. It strengthens our phase I study design to evaluate safety and tolerability and anti-tumor activity in patients with advanced solid malignancies or NHL (NCT02702492).

As a proof of concept, we have demonstrated that Dasatinib, a Src/Abl inhibitor approved for B-cell Acute Lymphoblastic Leukemia and Chronic Myelogenous Leukemia, is highly effective in PTEN-positive DLBCLs, irrespective of their COO class (Scuoppo et al., PNAS 2019)...First, we found that the activities of three chemically distinct drugs (FK-866, STF-118804 and KPT-9274) were highly correlated across the 34 lines DLBCL panel...These results were validated in xenotransplants of luciferized DLBCL lines and Patient Derived Xenotransplant models (PDXs) that were transcriptionally classified for the status of the Kynurenine De Novo signature. Together, these data support the repositioning of NAMPT inhibitors as a therapeutically relevant strategy for EZB-type GCB-DLBCLs.

Inhibition of SREBP signaling with dipyridamole enhanced the cytotoxicity of KPT-9274 on LSCs in vivo. Our work demonstrates that altered lipid homeostasis plays a key role in NAMPT inhibitor-induced apoptosis and identifies NAMPT inhibition as a therapeutic strategy for targeting LSCs in AML.

Pharmacological NAMPT inhibition by KPT9274 potently targeted genetically heterogeneous gliomas by activating mitochondrial dysfunction. Our preclinical results provide a rationale for targeting the NAMPT-dependent alternative NAD biosynthesis pathway as a novel clinical strategy against gliomas.

KPT-9274, given at (150 mg/kg) in combination with sub-MTD everolimus (2.5 mg/kg) significantly suppressed two PNET derived xenograft. These studies bring forward a well-grounded strategy for advanced PNETs that fail to respond to single-agent everolimus.

Importantly, niacin supplementation mitigated KPT-9274-caused kidney injury and EPO deficiency without affecting its efficacy. Altogether, our study delineated the mechanism of KPT-9274-mediated toxicity and sheds light onto developing strategies to improve the tolerability of this important anti-AML inhibitor.

Combining selinexor (SEL), a small molecule inhibitor of exportin 1 (XPO1) approved by the FDA for treatment of some hematologic malignancies, with the current therapies used for advanced breast cancers (e.g. tamoxifen) decreased metabolic adaptations in response to individual drug treatments and prevented colony formation in hydrogels and tumor growth in xenograft models. Since we observed a reliance on NAD+ metabolism in cancer cells that are treated with single therapies, in the current study we investigated co-targeting metabolic alterations using SEL and the NAMPT inhibitor KPT-9274. We established 3D cell culture systems in novel hydrogels derived from decellularized bone, lung, and liver tissues - the major sites of metastasis of ER+ breast cancers, and compared with standard Matrigel culture... Targeting drug and metastatic-site induced adaptations to regenerate new vulnerabilities in endocrine-resistant breast tumors are novel. Given the need for better strategies for improving therapy response of metastatic ER+ tumors, our findings show uncovering the role XPO1-NAMPT crosstalk plays in metastatic breast cancer could lead to new combined therapies that reduce mortality.

Our findings provide evidence that HDAC8 inhibition- or shSIRT6-induced DNA repair deficiencies are potently synergistic with NAMPT targeting, with minimal toxicity towards normal cells, providing a rationale for a novel-novel combination-based treatment for AML.

To explore the translational application of our findings, we tested whether dipyridamole (DP), a clinically approved anti-platelet agent with inhibitory activity against SREBP signaling, can be repurposed to enhance the anti-leukemic effects of KPT-9274. We further uncovered that NAMPT inhibition results in dysregulation of lipid homeostasis and induces a lipogenic response coordinated by SREBPs that protects AML cells against NAD+ depletion. These findings offer insights into drug combination strategies to enhance the efficacy of NAMPT inhibitors and provide the rationale for testing NAMPT inhibitors in the treatment of AML in clinical trials.

We demonstrate that the dual NAMPT and PAK4 modulators (KPT-9274 and KPT-9307) inhibit PDAC cell proliferation through down-regulation of Bad phosphorylation and up-regulation tumor suppressive miRNAs (miR-145, let-7c, let-7d, miR-34c, miR320 and miR-100). These results suggest that targeting PAK4 could become a promising approach to restore pro-apoptotic function of Bad and simultaneously activate tumor suppressive miRNAs in therapy resistant PDAC.