Explore the vast range of titles available.

Myostatin, a member of the transforming growth factor-β superfamily, is an attractive target for muscle disease therapy because of its role as a negative regulator of muscle growth and strength. Here, we describe a novel antibody therapeutic approach that maximizes the potential of myostatin-targeted therapy. We generated an antibody, GYM329, that specifically binds the latent form of myostatin and inhibits its activation. Additionally, via “sweeping antibody technology”, GYM329 reduces or “sweeps” myostatin in the muscle and plasma. Compared with conventional anti-myostatin agents, GYM329 and its surrogate antibody exhibit superior muscle strength-improvement effects in three different mouse disease models. We also demonstrate that the superior efficacy of GYM329 is due to its myostatin specificity and sweeping capability. Furthermore, we show that a GYM329 surrogate increases muscle mass in normal cynomolgus monkeys without any obvious toxicity. Our findings indicate the potential of GYM329 to improve muscle strength in patients with muscular disorders.

The yeast prion protein Sup35, which contains intrinsically disordered regions, forms amyloid fibrils responsible for a prion phenotype [PSI⁺]. Using high-speed atomic force microscopy (HS-AFM), we directly visualized the prion determinant domain (Sup35NM) and the formation of its oligomers and fibrils at subsecond and submolecular resolutions. Monomers with freely moving tail-like regions initially appeared in the images, and subsequently oligomers with distinct sizes of ∼1.7 and 3 to 4 nm progressively accumulated. Nevertheless, these oligomers did not form fibrils, even after an incubation for 2 h in the presence of monomers. Fibrils appeared after much longer monomer incubation. The fibril elongation occurred smoothly without discrete steps, suggesting gradual conversions of the incorporated monomers into cross-β structures. The individual oligomers were separated from each other and also from the fibrils by respective, identical lengths on the mica surface, probably due to repulsion caused by the freely moving disordered regions. Based on these HS-AFM observations, we propose that the freely moving tails of the monomers are incorporated into the fibril ends, and then the structural conversions to cross-β structures gradually occur.

In human celiac disease (CeD) HLA-DQ2.5 presents gluten peptides to antigen-specific CD4 + T cells, thereby instigating immune activation and enteropathy. Targeting HLA-DQ2.5 with neutralizing antibody for treating CeD may be plausible, yet using pan-HLA-DQ antibody risks affecting systemic immunity, while targeting selected gluten peptide:HLA-DQ2.5 complex (pHLA-DQ2.5) may be insufficient. Here we generate a TCR-like, neutralizing antibody (DONQ52) that broadly recognizes more than twenty-five distinct gluten pHLA-DQ2.5 through rabbit immunization with multi-epitope gluten pHLA-DQ2.5 and multidimensional optimization. Structural analyses show that the proline-rich and glutamine-rich motif of gluten epitopes critical for pathogenesis is flexibly recognized by multiple tyrosine residues present in the antibody paratope, implicating the mechanisms for the broad reactivity. In HLA-DQ2.5 transgenic mice, DONQ52 demonstrates favorable pharmacokinetics with high subcutaneous bioavailability, and blocks immunity to gluten while not affecting systemic immunity. Our results thus provide a rationale for clinical testing of DONQ52 in CeD. Targeting gluten antigens presents a plausible therapy option for celiac disease. Here the authors generate and characterize a broadly neutralizing antibody recognizing more than 25 gluten peptide:HLA-DQ2.5 complexes, with structural analyses implicating its mode of interaction, and with mouse in vivo studies supporting its therapeutic feasibility.

BackgroundOvarian cancer remains a formidable challenge in oncology, necessitating innovative therapeutic approaches. Claudin-6 (CLDN6), a member of the tight junction molecule CLDN family, exhibits negligible expression in healthy tissues but displays aberrant upregulation in various malignancies, including ovarian cancer. Although several therapeutic modalities targeting CLDN6 are currently under investigation, there is still a need for more potent therapeutic options. While T-cell engagers (TCEs) hold substantial promise as potent immunotherapeutic agents, their current efficacy and safety in terms of target antigen selection and T-cell exhaustion due to only CD3 stimulation without co-stimulation must be improved, particularly against solid tumors. To provide an efficacious treatment option for ovarian cancer, we generated SAIL66, a tri-specific antibody against CLDN6/CD3/CD137.MethodsUsing our proprietary next-generation TCE technology (Dual-Ig), SAIL66 was designed to bind to CLDN6 with one Fab and CD3/CD137 with the other, thereby activating T cells through CD3 activation and CD137 co-stimulation. The preclinical characterization of SAIL66 was performed in a series of in vitro and in vivo studies which included comparisons to a conventional TCE targeting CLDN6 and CD3.ResultsDespite the high similarity between CLDN6 and other CLDN family members, SAIL66 demonstrated high specificity for CLDN6, reducing the risk of off-target toxicity. In an in vitro co-culture assay with CLDN6-positive cancer cells, we confirmed that SAIL66 strongly activated the CD137 signal in the Jurkat reporter system, and preferentially induced activation of both CD4+ and CD8+ T cells isolated from human peripheral blood mononuclear cells compared to conventional TCEs. In vivo studies demonstrated that SAIL66 led to a more pronounced increase in intratumor T-cell infiltration and a decrease in exhausted T cells compared with conventional CLDN6 TCE by contribution of CD137 co-stimulation, resulting in better antitumor efficacy in tumor-bearing mouse models.ConclusionOur data demonstrate that SAIL66, designed to engage CLDN6, CD3, and CD137, has the potential to enhance antitumor activity and provide a potent therapeutic option for patients with ovarian and other solid tumors expressing CLDN6. Clinical trials are currently underway to evaluate the safety and efficacy of SAIL66.

There are no direct comparisons between escitalopram and paroxetine controlled release in patients with major depressive disorder (MDD). We conducted a 24-week, rater-masked, randomized trial of escitalopram (5-20 mg/day) versus paroxetine controlled release (12.5-50 mg/day) in patients with MDD (UMIN000011191). Patients with the diagnosis of moderate-to-severe MDD (a 17-item Hamilton Rating Scale for Depression [HAMD-17], with total score at baseline being ≥20) were recruited to participate in a parallel, randomized, controlled trial. The primary outcome for efficacy was an improvement in the 21-item HAMD (HAMD-21) total score at 24 weeks. The secondary outcomes were the response, remission, and discontinuation rates and the incidence of individual adverse events. A total of 88 patients with MDD (males, 61.4%; mean age, 40.8±13.4 years) were recruited. The discontinuation rate was 58.0% (escitalopram, 55.8%; paroxetine controlled release, 60.0%). Both escitalopram and paroxetine controlled-release treatment groups exhibited significant reduction in the HAMD-21 total score at 2, 4, 8, 12, and 24 weeks from the baseline. However, there were no significant differences in the HAMD-21 total score, response rate, remission rate, and discontinuation rate at any time point between the groups. In addition, there were no significant differences in the incidence of any individual adverse events (eg, nausea, vomiting, and somnolence) between the treatment groups. Our results suggest that escitalopram and paroxetine controlled release had similar efficacy and safety profiles in patients with MDD. One of the primary limitations of this study is the small sample size.

BackgroundClaudin-6 (CLDN6), one of the over 20 known human CLDN family members, is upregulated in many solid tumors but shows minimal or no expression in healthy adult tissues. This makes it an ideal target for cancer therapies. Although several approaches using various therapeutic modalities targeting CLDN6, including T cell engagers (TCE), CAR-T cells, and antibody drug conjugates, are currently under investigation, a more potent therapeutic option is still desirable.MethodsTo achieve successful clinical outcomes by enhancing immune activation, we generated SAIL66, a next generation TCE, named Dual-Ig®, which targets CLDN6. SAIL66 is a tri-specific monoclonal antibody designed to bind to CLDN6 on cancer cells with one Fab arm and to both CD3 and CD137 with the other Fab arm. This boosts immune activation through signal 1 and 2 in T cells more strongly than a conventional TCE which only binds to CD3 and activates signal 1. The preclinical characterization of SAIL66 was performed in a series of in vitro and in vivo studies, including direct comparisons to a conventional TCE targeting CLDN6 and CD3.ResultsSAIL66 revealed a high specificity for CLDN6, despite its high similarity to CLDN3, CLDN4, and CLDN9, suggesting that SAIL66 has no undesirable off-target toxicity in patients. Using a Jurkat cell system harboring NFAT or NF-κB reporter genes, we confirmed that SAIL66 exerts CD3 and CD137 signal induction activity depending on CLDN6 expression. SAIL66 induced activation of T cells, release of cytokines, and lysis of CLDN6-positive cancer cells. In vivo studies with immune competent syngeneic mouse models, engineered to express either human CD3 alone or both hCD3 and CD137, showed that SAIL66 exhibited better anti-tumor efficacy than a conventional TCE by inducing the activation of both CD3 and CD137. Notably, the increase in the number of intratumoral T cells and suppression of exhausted T cell populations were more remarkable in mice treated with SAIL66 than in those treated with a conventional TCE. Although SAIL66 monotherapy was effective in the immune checkpoint inhibitor (ICI) resistant non-immunogenic tumor, the anti-tumor efficacy was further improved by combining SAIL66 with ICI.ConclusionsSAIL66 offers a novel therapeutic option by incorporating CD137 co-stimulatory signaling in addition to CD3 signaling for the treatment of patients with cancer expressing CLDN6. Clinical studies of SAIL66 are currently underway for patients with solid cancer (NCT05735366).Ethics ApprovalAll in vivo procedures and the experiments with human materials were conducted in compliance with the guidelines of the Institutional Animal Care and Use Committee (IACUC) and research ethics comittee at Chugai Pharmaceutical.

BackgroundIntratumoral regulatory T cells (Tregs) are associated with diminished antitumor immunity and poor prognosis in many cancers, with tumor-infiltrating effector Tregs expressing high levels of cytotoxic T-lymphocyte-associated protein 4 (CTLA-4). While Treg depletion is a promising strategy for cancer immunotherapy, systemic Treg depletion may lead to severe autoimmune toxicity. Therefore, to selectively deplete intratumoral Tregs, we used extracellular ATP (exATP), which is highly elevated in solid tumors, as a tumor-selective small molecule.MethodsWe generated ROSE12, a novel anti-CTLA-4 Fc gamma receptors (FcγRs)-binding-enhanced-Fc exATP-dependent switch antibody that reduces Tregs only in the presence of exATP. We evaluated ATP-dependent binding affinity, antibody-dependent cellular cytotoxicity (ADCC) activity in vitro, and antitumor efficacy of monotherapy and combination therapy with anti-programmed death-ligand 1 (PD-L1) in CTLA-4/CD3 double humanized mouse models. Safety profiles were assessed in cynomolgus monkeys.ResultsROSE12 demonstrated ATP concentration-dependent binding to CTLA-4, with strong binding at 100 µmol/L but no binding without ATP. ROSE12 demonstrated stronger exATP-dependent ADCC activity in vitro and preferentially reduced CTLA-4+ Tregs over activated conventional T cells. The engineered asymmetric re-engineering technology-Fc (ART-Fc) region, a proprietary Fc engineering technology, showed enhanced binding to activating FcγRIIa and FcγRIIIa while reducing binding to inhibitory FcγRIIb. In mouse models, ROSE12 monotherapy significantly inhibited tumor growth in both conventional and PD-L1 therapy-resistant tumors by reducing intratumoral Tregs and increasing CD8+ T-cell infiltration. Combination therapy with anti-PD-L1 showed synergistic antitumor efficacy with enhanced intratumoral CD8+ T-cell activation without increasing systemic immune activation. Unlike FcγRs binding-enhanced conventional anti-CTLA-4, ROSE12 did not induce systemic immune activation or colitis symptoms, demonstrating a 30–300-fold wider therapeutic window. The tumor-selective mechanism was confirmed in humanized mouse models, where ROSE12 reduced only intratumoral Tregs while sparing splenic Tregs. In cynomolgus monkeys, ROSE12 was well tolerated even at 30 mg/kg/week compared with the 3–10 mg/kg/week limits for conventional anti-CTLA-4 antibodies such as non-fucosylated ipilimumab and ipilimumab.ConclusionsThese findings support the clinical development of ROSE12 as a tumor-selective Treg-depleting immunotherapy with potential efficacy in programmed cell death protein-1/PD-L1 therapy-resistant patients. The favorable safety profile was attributed to the ATP-dependent binding mechanism that restricts activity to the high-ATP tumor microenvironment. ROSE12 is currently being evaluated in phase I clinical trials (NCT05907980).

We conducted a cross-sectional survey to assess the prevalence of physical pain in Japanese major depressive disorder (MDD) and schizophrenia (SZ) patients as well as in healthy controls (HCs). We also examined the association between their psychopathology and characteristics of pain according to a face-to-face survey by an experienced psychiatrist and psychologist. We analyzed 233 HCs, 94 MDD patients, and 75 SZ patients using the McGill Pain Questionnaire (MPQ) and SF-8 (all participants), the Hamilton Depression Rating Scale 21 items (MDD patients), and the Positive and Negative Symptom Scale (SZ patients). Although MDD patients experienced more pain than HCs, there was no difference in the prevalence of pain between SZ patients and HCs. Moreover, HCs with pain did not have higher SF-8 total scores than those without pain, whereas both MDD and SZ patients with pain had higher SF-8 total scores than those without pain. The severity of psychopathology in MDD and SZ patients was also positively associated with both the prevalence of pain and MPQ scores. MPQ scores were also associated with positive symptoms in SZ patients. Considering these results, physicians need to query MDD patients about physical pain during examination if they are to ensure a favorable and quick response to treatment. The severity of positive symptoms (i.e., clinical status) in SZ patients might also be associated with pain sensitivity, and warrants further investigation.

Emicizumab, a factor (F)VIIIa-function mimetic bispecific antibody (BsAb) to FIXa and FX, has become an indispensable treatment for people with hemophilia A (PwHA). Although emicizumab is very potent, long-term outcomes from the clinical studies suggest that a small proportion of PwHA still experiences bleeds. Additionally, non-clinical studies indicate that the maximum cofactor activity of emicizumab is lower than international standard activity (100 IU/dL of FVIII). An increased cofactor activity BsAb would benefit such patients. Here, we report NXT007, a BsAb binding FIXa and FX developed through further engineering of emicizumab. Emicizumab has a common light chain, but through advances in antibody engineering, we were able to create a more potent BsAb with two new non-common light chains. After extensive optimization of the heavy and light chains, the resulting BsAb, NXT007, exerted in vitro thrombin generation (TG) activity in hemophilia A plasma equivalent to 100 IU/dL of FVIII when triggered by tissue factor. NXT007 demonstrated potent hemostatic activity in an acquired hemophilia A model in non-human primates at a much lower dosage than emicizumab, consistent with an around 30-fold dose shift in the in vitro TG activity between NXT007 and emicizumab. Moreover, together with Fc engineering that enhanced FcRn binding and reduced in vivo clearance, we demonstrate that NXT007 could be effective at a much lower dosage with a longer dosing interval compared to emicizumab. These non-clinical results suggest that NXT007 could maintain a non-hemophilic range of coagulation potential in PwHA and provides a rationale for its clinical testing.