In addition, the immunosuppressive microenvironment exacerbated by postoperative hypoxia is degraded via the cooperation of NLG919, which blocks the IDO-1 signaling pathway and CaCO3, which consumes lactic acid. Based on these improvements, well-designed MOFs effectively inhibit bilateral tumor growth/metastasis and offer a successful paradigm for improving the overall prognosis of HIFU.

An ongoing first-in-human (FIH) phase 1/2 clinical trial (NCT05533697) will evaluate the safety and antitumor activity of mRNA-4359 when administered alone and in combination with the anti-programmed death-1 agent pembrolizumab in participants with advanced solid tumors. Finally, the IS/ID modeling analysis determined that a 100 μg dose of mRNA-4359 would be the most appropriate starting dose for FIH trials. The described approach represents a unique application of IS/ID modeling to determine a therapeutically relevant FIH starting dose in the absence of supporting preclinical animal data.

Here, an iridium (Ir)-based nanozyme (IIN) was constructed through coordination-driven co-assembly using photosensitizer indocyanine green (ICG), Ir, and indoleamine 2,3-dioxygenase (IDO) inhibitor NLG8189...Furthermore, it could suppress distant tumor progression by triggering the immune response, especially under photothermal irradiation, which was accompanied by increased DC maturation, M1 macrophage polarization, and T cell infiltration in tumor tissue. This study proposed a promising strategy for effective Ir-based nanozyme in tumor immunotherapy.

In this study, we produced near-infrared (NIR)-induced multi-shell upconversion nanoparticle (MUN)-based therapeutic nanocarriers co-loaded with chlorin e6 (Ce6) and indoximod (IND) (FMUN3-Ce6/IND) to combine tumor-targeted photodynamic therapy (PDT) with immunotherapy...Furthermore, the synergistic antitumor efficacy of FMUN3-Ce6/IND combining PDT and immunotherapy under in vivo conditions is demonstrated. These results suggest that multi-shell FMUN-based nanocarriers offer a promising platform for synergistic combination therapy, addressing the limitations of monotherapy with IDO inhibitors and overcoming the restricted tissue penetration and low ROS generation associated with conventional PDT.

Four novel Ir(III)/Re(I)-1-methyl-D-tryptophan conjugates (Ir-MT-1-2 and Re-MT-1-2) were designed and synthesized for the first time, among which 1-methyl-D-tryptophan (1-MT) is an indoleamine 2,3-dioxygenase (IDO) inhibitor...Mechanistic investigations revealed that these complexes selectively localized to mitochondria, inducing mitochondrial membrane potential (MMP) depolarization, elevating intracellular reactive oxygen species (ROS) levels, activating mitochondrial apoptotic pathways, and simultaneously inducing the cleavage of pyroptosis marker (GSDME) to cause pyroptosis. These results demonstrate the potential of combing transition metals with IDO inhibitors for cancer treatment.

In this study, a formulation of DOX/IND-loaded liposomes camouflaged with ovarian cancer cell membranes is successfully developed, and their stable physicochemical properties are confirmed. As an effective nanodrug delivery system, DOX/IND@cmLPs exhibited enhanced tumor-targeting and immune-mediated anticancer activity both in vitro and in vivo, indicating their potential as a platform for future combined chemotherapy and immunotherapy.

P2, N=17, Terminated, Cliniques universitaires Saint-Luc- Université Catholique de Louvain | Trial completion date: Jun 2024 --> Mar 2025 | Recruiting --> Terminated; unmet primary endpoint

By studying the turnover of IDO1 protein in human tumor cells exposed to various IDO1 catalytic inhibitors, such as epacadostat, linrodostat, and navoximod, we show here that these molecules stabilize a non-enzymatic protein conformation of IDO1, independently of their mechanism of inhibition. In the thyroid carcinoma cell line FTC-133, the stabilized and non-enzymatic IDO1 protein promotes the proliferation and migration of the tumor, resulting in an adverse pro-tumorigenic effect. These results uncover an unexpected adverse effect of IDO1 inhibitors in the tumor microenvironment that overcomes the enzymatic inhibition of IDO1, and suggest protein degradation, rather than enzymatic inhibition, as a more effective approach to target IDO1 in the tumor microenvironment.

P2, N=43, Active, not recruiting, Memorial Sloan Kettering Cancer Center | Recruiting --> Active, not recruiting

These findings suggest a potential inhibitory mechanism for PF-06840003 and offer valuable structural insights for the rational design of potent IDO1 inhibitors. It should be noted that the inhibitory activity of the designed lead compounds is based solely on computational predictions; experimental validation through in vitro and in vivo studies is still required to confirm their actual inhibitory effects and pharmacokinetic properties.

P1/2, N=361, Recruiting, ModernaTX, Inc. | N=194 --> 361 | Trial completion date: Dec 2027 --> Feb 2032 | Trial primary completion date: Dec 2027 --> Feb 2032

A few IDO1 inhibitors have reached the clinical stage, including navoximod, epacadostat and linrodostat. Using second harmonic generation analysis (SHG) and molecular dynamics simulations, here we show that these clinical inhibitors can induce distinct allosteric motions in the enzyme that affect the stability of the transient signaling complex between IDO1 and Src tyrosine kinase. Next generation sequencing demonstrates that, despite sharing a similar ability to inhibit the enzyme's catalytic function, all three catalytic inhibitors modulate the IDO1's signaling function in different ways, regulating distinct transcriptomes in SKOV3 cells.