Turalio (pexidartinib)

P3, N=40, Active, not recruiting, Daiichi Sankyo Co., Ltd. | Trial completion date: Mar 2024 --> Feb 2026

P=N/A, N=6, Active, not recruiting, Daiichi Sankyo Co., Ltd. | Phase classification: P1/2 --> P=N/A | Trial completion date: Mar 2024 --> Mar 2025

Oxygen-glucose deprivation causes an increase in NR4A1 mRNA in astrocytes as well as its nuclear to cytoplasmic transfer. Furthermore, reoxygenation enhances NR4A1 transcription and promotes its nuclear translocation.

P1/2, N=43, Active, not recruiting, Gulam Manji | Recruiting --> Active, not recruiting | Phase classification: P2 --> P1/2 | Trial completion date: Mar 2024 --> Jun 2024

RNA-seq further confirms the enhanced immune cell function. Consequently, P@ZIF/M1-KTP has great potential as a novel adoptive cellular therapeutic strategy for tumors.

In vivo, PXB17 significantly halted CRC growth, with a stronger effect than PLX3397. In particular, PXB17 potently enhanced therapeutic activity of PD-1 mAb in CT-26 (MSS) model and prevented tumor recurrence in MC-38 (MSI-H) model by promoting formation of long-term memory immunity. Our study opens a new avenue for CSF1R in tumor innate and adaptive anti-tumor immunomodulatory activity and suggests that PXB17 is a promising immunotherapy molecule for enhancing the efficacy of PD-1 mAb or reducing tumor recurrence of CRC.

Treatment by PLX3397 in combination with paclitaxel significantly inhibited the growth of ovarian cancer both in vitro and in vivo. Blockade of CSF-1R altered the macrophage phenotype and reprogrammed the immunosuppressive cell population in the tumor microenvironment.

Our results demonstrate that pexidartinib, through the inhibition of FLT3 signaling, has a deleterious effect on DC differentiation, which may explain the limited antitumor clinical activity observed in this study. This work suggests that inhibition of FLT3 should be considered when combining TKIs with immune checkpoint inhibitors.

The results of immunoblotting assays suggested that silybinin as well as compound glycyrrhizin inhibited the protein expression of CYP3A4 and CYP2C9 in rats. Therefore, the combination of pexidartinib with silybinin and compound glycyrrhizin should be monitored to avoid clinical adverse effects.

This comparative analysis of CSF1R-targeting drugs on patient-derived GAMs and human glioblastoma avatars identified GW2580 as the most powerful inhibitor with the ability to polarize immunosuppressive GAMs to a proinflammatory phenotype, supporting antitumor T cell responses while also exerting a direct antitumor effect. These data indicate that GW2580 could be an important pillar in future therapies for glioblastoma.

Combination treatment also induced favorable systemic antitumor immunity in the spleen and lymph node. In conclusion, our findings provide insights into the synergy between mDex-based immunotherapy and PLX-3397 as the combination overcame the disadvantages associated with monotherapy and offer a therapeutic strategy for the treatment of solid tumors including melanoma.

Their temporal alteration suggests an association with tumor recurrence after BNCT, making M-MDSCs a potential intervention target. Our preliminary results showed that PLX-3397 had strong M-MDSCs, TAMs, and TIL (tumor-infiltrating lymphocyte) modulating effects that could synergize tumor control when combined with BNCT.

P1, N=54, Recruiting, National Cancer Institute (NCI) | Trial completion date: Dec 2024 --> Dec 2025 | Trial primary completion date: Dec 2024 --> Dec 2025

POx-Man nanovaccine combines with pexidartinib, a modulator of the TAM function, restricts the MC38 tumor growth, and synergizes with PD-1 blockade, controlling MC38 and CT26 tumor growth and survival. This data is further validated in the highly aggressive and poorly immunogenic B16F10 melanoma mouse model. Therefore, the synergistic anti-tumor effect induced by the combination of nanovaccines with the inhibition of both TAM- and PD-1-inducing immunosuppression, holds great potential for improving immunotherapy outcomes in solid cancer patients.

The cell membrane-derived nanoparticles (CMNPs) deriving from the MiaPaCa-2 cells (MPC2-CMNPs) were loaded with the chemotherapeutic drug paclitaxel (PTX), and the CMNPs deriving from M2-polarized macrophages (M2-CMNPs) were loaded with the colony-stimulating factor 1 receptor inhibitor, pexidartinib (PXDB). Finally, we evaluated the PTX and PXDB-loaded CMNPs' effect on the viability of all the used TME cell lines alone or in combination. Overall, this pilot study showed the potential of the CMNPs to cross an in vitro stroma model and act synergistically to treat PDAC.

In the current study, the metabolic activation of PEX was investigated in human/mouse liver microsomes (HLM/MLM) and primary human hepatocytes (PHH) using glutathione (GSH) and methoxyamine (NHOMe) as trapping reagents. CYP3A4 and CYP3A5 were identified as the primary enzymes responsible for the formation of these adducts using recombinant human P450s and CYP3A chemical inhibitor ketoconazole. Overall, our studies suggested that PEX metabolism can produce reactive metabolites mediated by CYP3A, and the association of the reactive metabolites with PEX hepatotoxicity needs to be further studied.

In Asian patients with symptomatic TGCT not amenable to improvement with surgery, pexidartinib demonstrated clinical benefit in tumor response and improvement in joint function. The overall safety profile of pexidartinib was comparable with previous data. Hepatotoxicity was manageable with frequent liver test monitoring and dose modifications as defined in the protocol, and no new safety signals were observed in this Asian population.

Pts with TGCT not amenable to surgery who received prior anti-CSF1/CSF1R therapy (including pexidartinib, cabiralizumab, or vimseltinib) were enrolled and treated with vimseltinib 30 mg twice weekly (recommended phase 2 dose). Longer follow-up demonstrated that vimseltinib continued to be well tolerated with a manageable safety profile in pts with TGCT not amenable to surgery who received prior anti-CSF1/CSF1R therapy. Antitumor activity continued to improve in this pretreated population, with an increased ORR. At week 25, all responders experienced ≥30% reductions in worst and average pain.

In two preclinical mouse models of MPNST, we combined the oncolytic virus T-VEC with myeloid-cell targeting therapeutics, Pexidartinib or Trabectedin, to assess the combination therapy's antitumor efficacy and survival benefits. Our findings provide compelling evidence that myelomodulatory therapies can augment the antitumor T-cell response and improve the therapeutic benefits of oncolytic virotherapy in murine models of MPNST. These results provide valuable insights for designing and implementing future immunotherapeutic strategies in the management of MPNST.

To assess the mechanism of CSF-1-mediated suppression of immunotherapy, Isolated PBMC, activated with phytohemagglutinin (PHA) with or without pembrolizumab (20 nM), were cultured alone, or in the presence of macrophages or on an established NSCLC monolayer...The use of Pexidartinib (PLX-3397), a CSF-1R inhibitor, reversed the effects of CSF-1 by restoring lymphocyte activation. However, these effects were dependent on the presence of monocytes/macrophages, suggesting that the immune suppression mediated by CSF-1 was an indirect effect resulting from the stimulation of monocytes that promote their differentiation into macrophages. Conclusions Our study suggests that plasma levels of CSF-1 could serve as a useful predictive biomarker for resistance to ICIs, while targeting the CSF-1/CSF-1R signaling pathway could potentially overcome resistance to ICIs in patients with NSCLC.

The presence of immunosuppressive immune cells in tumors is a significant barrier to the generation of therapeutic immune responses. In addition, we demonstrate that the PTX and PLX3397 combination provides consistent therapeutic improvement across several TNBC models, resulting from the repolarization of the immunosuppressive TME and enhanced T cell immune response that suppress both the primary tumor growth and metastasis. Overall, the work emphasizes the benefit of drug reformulation and outlines potential translational path for both PTX and PTX with PLX3397 combination therapy using POx polymeric micelles for the treatment of TNBC.

Moreover, some of them have been on the market or in clinical trials for the treatment of some kinase-related diseases (e.g., vemurafenib, pexidartinib, decernotinib). In addition, the binding modes of some azaindoles complexed with kinases were also investigated during the SARs elucidation. This review may offer an insight for medicinal chemists to rationally design more potent kinase inhibitors bearing the azaindole scaffold.

P2, N=21, Recruiting, Daiichi Sankyo Co., Ltd. | Trial completion date: Jun 2024 --> Nov 2026 | Trial primary completion date: Mar 2023 --> Feb 2025

Pexidartinib is the first CSF-1 receptor inhibitor approved for the treatment of TGCT. Here, we discuss various available treatment strategies and ongoing investigations and trials targeting diffuse TGCT, which include nilotinib, lacnotuzumab, cabiralizumab, vimseltinib, and emactuzumab.

Results show that IWR-1 could not only rescue developmental defects and immune cell number, but also downregulate the high expression of Wnt signaling pathway and inflammation-related caused by pexidartinib. Collectively, our results suggest that pexidartinib induces the developmental toxicity and immunotoxicity in zebrafish embryos through hyperactivation of Wnt signaling, providing a certain reference for the new mechanisms of pexidartinib function.

In vivo efficacy verified that s-T-NPs formulation was much more effective than ns-T-NPs and other PLX3397 formulations to treat B16F10 melanoma via targeting TAM depletion and modulating tumor immune microenvironment. Overall, this study provides a robust and promising nanomedicine strategy for TAM-targeted cancer immunotherapy.

P1/2, N=6, Active, not recruiting, Daiichi Sankyo Co., Ltd. | Trial completion date: Mar 2023 --> Mar 2024

We previously demonstrated that inhibition of TAM infiltration into glioma tumors with the CSF-1R antagonist pexidartinib (PLX3397) can inhibit glioma cell invasion in-vitro and in-vivo...In addition, glioma conditioned media treatment of microglia resulted in a rapid upregulation of gene expression of several CCR1 ligands including CCL3, CCL5, CCL6 and CCL9. These data support the existence of tumor stimulated autocrine loop within TAMs which ultimately mediates tumor cell invasion.

Meanwhile, compared with pexidartinib monotherapy, the combination treatment further switches the polarization status of tumor-associated macrophages. In summary, our results showed that the combination of pexidartinib and PD-1 antibody showed a synergy and significantly improved the anti-tumor efficacy, through pexidartinib increasing CD8T/Treg ratio by reducing TAM-derived CCL22.

The pharmacological (PLX3397) or genetic conditional (Siglechdtr het/CX3CR1GFP het) conditional depletion of microglia canceled both the increased phagocytosis and the extended survival time, suggesting that the effect of “don't eat me” signals was microglia dependent...We are further developing a method for isolating LUCs fluorescently labeled in vivo using holographic 2-photon microscopy for evaluating single cell gene expression profiles. Using the novel techniques, the spatio-temporal information can be integrated across the molecular, cellular and tissue levels that allow us to further investigate the dynamic behavior of not only tumors, but also microglia and neurons.

The survival rate decreases significantly for patients who develop OS lung metastasis (OSLM).Purpose: To assess the safety and efficacy of colony-stimulating factor-1 receptor inhibitor (CSF-1Ri) (Pexidartinib; PLX) in shifting the OSLM tumor microenvironment (TME) to an anti-tumorigenic state upon local delivery to lungs of a syngeneic mouse model of OSLM. The safety of PLX upon repeated pulmonary administration (9 doses, every other day at 2 mg/kg) in healthy BALB/c mice was assessed using health scoring, pulmonary mechanics, molecular and cellular composition of bronchoalveolar lavage fluid (BALF), blood count and plasma biochemistry, and H&E of lungs and liver... We demonstrated that repeated doses of PLX is safe upon local delivery to the lungs of murine model of OSLM, with no alternations in lungs or liver tissue. We further showed that PLX reduces tumor burden, which correlates with a change in the immune phenotype of the OSLM toward a more anti-tumorigenic profile. These results are clinically relevant as PLX has been approved by the FDA, thus opening opportunities for its repurposing to support standard of care therapy in OSLM.

Systemic agents such as tyrosine kinase inhibitors (e.g., nilotinib and imatinib) or agents targeting the CSF-1 (colony-stimulating factor-1) pathway (e.g., pexidartinib and emactuzumab) are active against TGCT. This will also reduce the risk of a postoperative nerve palsy.Although separate instruments for the anterior and posterior portions of the procedure are not necessary, separate drapes, gown, and gloves and other preoperative preparation should be readied in advance for the second portion of the procedure in order to save operative time. PVNS = pigmented villonodular synovitisROM = range of motionMRI = magnetic resonance imagingGastroc = gastrocnemiusPDS = polydioxanone sutureCAM = controlled ankle motionASA = acetylsalicylic acid (aspirin).

Conclusion Our findings suggest pexidartinib is a potential agent for treating ATC. Co-administration with an Nrf2 inhibitor is an effective synergistic strategy.

Our findings revealed that CSF1R is a novel identified dependence receptor silenced in CRC. The silence abalienates its ligands to stimulate CSF1R expressed on M2 TAMs, which is an appealing therapeutic target for M2 TAM depletion and CRC treatment.

In addition, the BAX/BCL-2 ratio increased in cells treated with pexidartinib and sotuletinib. With the four novel TGCT cell lines, we have an excellent model for further in vitro and in vivo studies.

The physiologically based pharmacokinetic model predicted that a moderate CYP3A4 inhibitor and a moderate CYP3A inducer would produce modest increases and decreases, respectively, in pexidartinib exposure. These results provide a basis for pexidartinib dosing recommendations when administered concomitantly with drugs with drug-drug interaction potential, including dose adjustments when concomitant administration cannot be avoided.

In a chick chorioallantoic membrane (CAM) tumor model implanted with Hep3B cells, tumor growth and tumor-induced angiogenesis were significantly blocked by compound 3 to a similar extent as pexidartinib (1). Overall, compound 3, a bioisostere of pexidartinib, is an effective dual inhibitor to block CSF1R kinase and CSF1 production, resulting in significant inhibition of tumor growth.