Potent JAK3 Inhibitors Research Articles

CS12192: A novel selective and potent JAK3 inhibitor mitigates acute graft-versus-host disease in bone marrow transplantation

BackgroundDespite the significant role of JAK3 in various autoimmune diseases, including graft-versus-host disease (GVHD), there has been a lack of potent and selective JAK3 inhibitors specifically studied for GVHD. In our preclinical investigations, we evaluated a novel JAK3 inhibitor called CS12192, which is already undergoing clinical investigation in autoimmune diseases. MethodsWe evaluated the efficacy of CS12192 in GVHD through mixed lymphocyte reaction (MLR) in both mouse and human cells, as well as allogeneic bone marrow transplantation (BMT) in a murine model. ResultsCS12192, starting at a concentration of 0.5 μM, dose-dependently reduced the intracellular positivity for cytokines TNF-α and IFN-γ in CD4+ T cells (p < 0.05 to p < 0.0001) and CD8+ T cells (p < 0.01 to p < 0.0001) during mouse allogeneic MLR assays. This effect was observed for both single and double positivity of the cytokines. Moreover, In MLR assays with three different human donors, CS12192 also demonstrated a dose-dependent reduction in the proportion of IFN-γ positive CD4+ T cells (p < 0.0001) and CD8+ T cells (p < 0.01 to p < 0.0001). Additionally, it suppressed T cell proliferation in the mouse MLR (p < 0.05 to p < 0.0001), but this effect was observed in only one human donor (p < 0.001 to p < 0.0001). Furthermore, the administration of CS12192 at 40 and 80 mg/kg BID significantly improved the survival rate in the BMT model, resulting in cumulative 62-day survival rates of 88.89% (p < 0.01) and 100% (p < 0.001), respectively, compared with prednisolone (p < 0.05). ConclusionsCS12192 is a novel, potent and selective JAK3 inhibitor demonstrating great potential to mitigate acute GVHD.

QSAR-driven screening uncovers and designs novel pyrimidine-4,6-diamine derivatives as potent JAK3 inhibitors

This study presents a robust and integrated methodology that harnesses a range of computational techniques to facilitate the design and prediction of new inhibitors targeting the JAK3/STAT pathway. This methodology encompasses several strategies, including QSAR analysis, pharmacophore modeling, ADMET prediction, covalent docking, molecular dynamics (MD) simulations, and the calculation of binding free energies (MM/GBSA). An efficacious QSAR model was meticulously crafted through the employment of multiple linear regression (MLR). The initial MLR model underwent further refinement employing an artificial neural network (ANN) methodology aimed at minimizing predictive errors. Notably, both MLR and ANN exhibited commendable performance, showcasing R2 values of 0.89 and 0.95, respectively. The model's precision was assessed via leave-one-out cross-validation (CV) yielding a Q2 value of 0.65, supplemented by rigorous Y-randomization. , The pharmacophore model effectively differentiated between active and inactive drugs, identifying potential JAK3 inhibitors, and demonstrated validity with an ROC value of 0.86. The newly discovered and designed inhibitors exhibited high inhibitory potency, ranging from 6 to 8, as accurately predicted by the QSAR models. Comparative analysis with FDA-approved Tofacitinib revealed that the new compounds exhibited promising ADMET properties and strong covalent docking (CovDock) interactions. The stability of the new discovered and designed inhibitors within the JAK3 binding site was confirmed through 500 ns MD simulations, while MM/GBSA calculations supported their binding affinity. Additionally, a retrosynthetic study was conducted to facilitate the synthesis of these potential JAK3/STAT inhibitors. The overall integrated approach demonstrates the feasibility of designing novel JAK3/STAT inhibitors with robust efficacy and excellent ADMET characteristics that surpass Tofacitinib by a significant margin.Communicated by Ramaswamy H. Sarma

Design, synthesis, and biological evaluation of cyano-substituted 2,4-diarylaminopyrimidines as potent JAK3 inhibitors for the treatment of B-cell lymphoma

A series of cyano-substituted 2,4-diarylaminopyrimidines was designed and synthesized as potent non-covalent JAK3 inhibitors. Among the derivatives synthesized, 9o (IC50 = 22.86 nM), 9 k (IC50 = 21.58 nM), and 9j (IC50 = 20.66 nM) demonstrated inhibitory potencies against JAK3 similar to the known JAK3 inhibitor tofacitinib (IC50 = 20.10 nM). Moreover, 9o displayed potent anti-proliferative activities against Raji and Ramos cells, with IC50 values of 0.9255 μM and 1.405 μM, respectively. In addition, 9o demonstrated low toxicity in normal HBE (human bronchial epithelial cells, IC50 > 10 μΜ) and L-02 (human liver cells, IC50 = 3.104 μΜ) cells. Analysis of the mode of action by flow cytometry indicated that 9o effectively arrested Raji cells at the G2/M phase. Taken together, these results suggested that 9o might be a promising candidate for development as a potential treatment for B-cell lymphoma.

The Combination of Venetoclax and Tofacitinib Induced Hematological Responses in Patients with Relapse/ Refractory T-ALL with BCL2 Expression and Surface IL7R Expression or IL7R-Pathway Mutations (On behalf of the GRAALL)

Background. We previously reported that IL7R-pathway genes are mutated in 29% of T-ALL and that surface IL7R is expressed in 53% of T-ALL (Rathana K et al. abstract S131, EHA 2019). In these samples, in vitro and in vivo (IL7R+PDX T-ALL) sensitivity to JAK inhibitors is determined by the expression of IL7R regardless of the IL7Rp genomic status. BCL2 inhibition has been shown to be synergistic with the IL7R pathway inhibition (Degrise S et al., Leukemia 2018;32(3):788-800). We therefore explored whether the combination of tofacitinib, a potent JAK3 inhibitor, with venetoclax may improve the hematological status of patients with relapse/refractory T-ALL. Methods. Patients with relapse/refractory T-ALL, with surface IL7R expression or IL7R-pathway mutations and BCL2 expression were eligible if they had failed all available therapeutic options (including clofarabine and/or allogenic HSCT if eligible). Patients were offered to be treated with venetoclax, 100 mg/d day1; 200 mg/d day2; 300 mg/d day3 and 400 mg/day thereafter and for subsequent 28 days cycles combined with tofacitinib, 10mg twice a day started from day 5 cycle 1 (off-label use). Responses were assessed after cycle 1 and cycle 3. Responding patients may continue therapy until relapse, death or allogenic HSCT if eligible. Results. Eight patients were treated including 7 ETP-ALL and 1 T-cell lymphoblastic lymphoma. Median age was 56 years (27-69) and sex ratio (M/F) was 4/4. Four patients were refractory to at least 2 lines of therapy and 4 patients relapsed, all on therapy. Relapsing patients were in failure after at least one salvage therapy. All patients expressed BCL2. A mutation of JAK3 L857P was found in 5 cases including one patient with both JAK3 and JAK1 mutations. except one with a mutation of IL7-R. Other patients expressed IL7R. A response to therapy was observed in 5 out of seven evaluable cases (71%) including 2 CR associated with a negative MRD (sensitivity 10-4) and 3 partial responses (medullar blasts less than 15%). The remaining patient has just started the first cycle of therapy. Duration of responses was 10 months and +6 months (allo HSCT planned) for the 2 patients in CR and 3 months or less for the partial responders. No serious adverse event related to therapy was observed. Conclusion. IL7-pathway is a possible target for therapy with JAK inhibitors in patients with T-ALL in relapse or refractory to conventional therapy. A combination of venetoclax and tofacitinib may offer a potential savage for these patients with limited therapeutic options. Disclosures Chevallier: Daiichi Sankyo: Honoraria; Incyte: Consultancy, Honoraria; Jazz Pharmaceuticals: Honoraria. Dombret:Institut de Recherches Internationales Servier (IRIS): Research Funding; AGIOS: Honoraria; CELGENE: Consultancy, Honoraria. Boissel:NOVARTIS: Consultancy. Rousselot:Pfizer: Research Funding; Incyte: Research Funding. OffLabel Disclosure: Venetoclax in T-ALL Tofacitinib in T-ALL

Oncogenic activation of JAK3-STAT signaling confers clinical sensitivity to PRN371, a novel selective and potent JAK3 inhibitor, in natural killer/T-cell lymphoma

Aberrant activation of the JAK3-STAT signaling pathway is a characteristic feature of many hematological malignancies. In particular, hyperactivity of this cascade has been observed in natural killer/T-cell lymphoma (NKTL) cases. Although the first-in-class JAK3 inhibitor tofacitinib blocks JAK3 activity in NKTL both in vitro and in vivo, its clinical utilization in cancer therapy has been limited by the pan-JAK inhibition activity. To improve the therapeutic efficacy of JAK3 inhibition in NKTL, we have developed a highly selective and durable JAK3 inhibitor PRN371 that potently inhibits JAK3 activity over the other JAK family members JAK1, JAK2, and TYK2. PRN371 effectively suppresses NKTL cell proliferation and induces apoptosis through abrogation of the JAK3-STAT signaling. Moreover, the activity of PRN371 has a more durable inhibition on JAK3 compared to tofacitinib in vitro, leading to significant tumor growth inhibition in a NKTL xenograft model harboring JAK3 activating mutation. These findings provide a novel therapeutic approach for the treatment of NKTL.

Solution-phase parallel synthesis of ruxolitinib-derived Janus kinase inhibitors via copper-catalyzed azide-alkyne cycloaddition.

A solution-phase parallel synthesis of triazole-derived ruxolitinib analogues was developed in the current study. The method employs copper-catalyzed azide-alkyne cycloaddition to build up the central triazole template. Product isolation by precipitation and centrifugation is straightforward and yields high purity compounds suited for biological profiling. A simple protocol for accessing the terminal alkyne precursors in high yields was established and a library of ruxolitinib-like triazoles featuring diverse functional groups was prepared. In addition, a model for the binding mode of ruxolitinib to Janus kinase (JAK) 2 is proposed. In contrast to previous models, the pose explains the compound selectivity for JAK1/JAK2 and is in accordance with published structure-activity data. On this basis, a structure-based design hypothesis for inverting the selectivity profile of ruxolitinib is deduced. Application of this strategy identified a moderately potent JAK3 inhibitor (35 nM) with high selectivity against other JAKs, potentially exploiting a covalent binding mode.

Anilino-monoindolylmaleimides as potent and selective JAK3 inhibitors

We designed a series of anilino-indoylmaleimides based on structural elements from literature JAK3 inhibitors 3 and 4, and our lead 5. These new compounds were tested as inhibitors of JAKs 1, 2 and 3 and TYK2 for therapeutic intervention in rheumatoid arthritis (RA). Our requirements, based on current scientific rationale for optimum efficacy against RA with reduced side effects, was for potent, mixed JAK1 and 3 inhibition, and selectivity over JAK2. Our efforts yielded a potent JAK3 inhibitor 11d and its eutomer 11e. These compounds were highly selective for inhibition of JAK3 over JAK2 and TYK. The compounds displayed only modest JAK1 inhibition.

Design, synthesis, biological evaluation and molecular docking of novel metronidazole derivatives as selective and potent JAK3 inhibitors

Two series of novel metronidazole derivatives as potential inhibitors targeting JAK have been designed, synthesized and their biological activities were also evaluated.

Strategic use of conformational bias and structure based design to identify potent JAK3 inhibitors with improved selectivity against the JAK family and the kinome

Using a structure based design approach we have identified a series of indazole substituted pyrrolopyrazines, which are potent inhibitors of JAK3. Intramolecular electronic repulsion was used as a strategy to induce a strong conformational bias within the ligand. Compounds bearing this conformation participated in a favorable hydrophobic interaction with a cysteine residue in the JAK3 binding pocket, which imparted high selectivity versus the kinome and improved selectivity within the JAK family.

Identification of a Potent Janus Kinase 3 Inhibitor with High Selectivity within the Janus Kinase Family

We describe a synthetic approach toward the rapid modification of phenyl-indolyl maleimides and the discovery of potent Jak3 inhibitor 1 with high selectivity within the Jak kinase family. We provide a rationale for this unprecedented selectivity based on the X-ray crystal structure of an analogue of 1 bound to the ATP-binding site of Jak3. While equally potent compared to the Pfizer pan Jak inhibitor CP-690,550 (2) in an enzymatic Jak3 assay, compound 1 was found to be 20-fold less potent in cellular assays measuring cytokine-triggered signaling through cytokine receptors containing the common γ chain (γC). Contrary to compound 1, compound 2 inhibited Jak1 in addition to Jak3. Permeability and cellular concentrations of compounds 1 and 2 were similar. As Jak3 always cooperates with Jak1 for signaling, we speculate that specific inhibition of Jak3 is not sufficient to efficiently block γC cytokine signal transduction required for strong immunosuppression.

ChemInform Abstract: Synthesis Staurosporines via a Ring Closing Metathesis Strategy as Potent JAK3 Inhibitors and Modulators of Allergic Responses.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Synthetic staurosporines via a ring closing metathesis strategy as potent JAK3 inhibitors and modulators of allergic responses

The synthesis and biological evaluation of JAK3 based staurosporine compounds is described. The compounds are constructed completely de novo, and a ring closing metathesis strategy is used to assemble the sugar mimetic portion. These analogs show potent JAK3 activity against isolated enzyme and in T-cells. One analog ( 32) showed unique biological effects during in vitro and in vivo tests including inhibition of STAT5 phosphorylation, blockade of mast cell responses, and reduction of JAK3 based effects in mice models of allergic disease.