EA Pharma (Japan)

Abstract Extracellular glutathione (GSH) is degraded on the cell surface, in which the γ-glutamyl residue is removed to generate cysteine–glycine (Cys–Gly) dipeptides that are subsequently transported to the cytoplasm. Carnosine dipeptidase II (CNDP2) is a cytoplasmic enzyme that hydrolyzes Cys–Gly and plays an important role in maintaining intracellular cysteine (Cys) homeostasis. CNDP2-mediated hydrolysis of Cys–Gly promotes Cys mobilization and contributes to the replenishment of intracellular GSH levels. CNDP2 is frequently overexpressed in various cancers and has been implicated in tumor cell proliferation and progression. This mechanism may enhance cancer cell survival by causing resistance to oxidative stress, which indicates that CNDP2 is a potential therapeutic target for cancer treatment. Although bestatin (BES) has been identified as a CNDP2 inhibitor, its limited specificity and suboptimal drug-like properties have limited its therapeutic potential. In this study, we performed an in silico screen of a small-molecule compound library and identified KKL-35 as a novel CNDP2-binding molecule. Molecular dynamics (MD) simulations suggested that KKL-35 interacts within the catalytic pocket. Biochemical assays confirmed that it inhibits CNDP2 enzymatic activity, albeit with lower potency compared with BES. Despite its modest intrinsic activity, KKL-35 exhibits favorable physicochemical and pharmacokinetic properties, which are characterized by a low topological polar surface area (TPSA), reduced molecular flexibility, and well-balanced lipophilicity. This positions it as an attractive and tractable starting point for lead optimization. Taken together, these findings establish KKL-35 as a validated CNDP2 inhibitor and a promising lead compound for the development of more selective therapeutics targeting CNDP2-mediated cancer cell metabolism.

ObjectiveTo evaluate the efficacy and safety of amifampridine (3,4-diaminopyridine) phosphate in Japanese adults with Lambert-Eaton myasthenic syndrome (LEMS).MethodsThe LMS-005 study was an uncontrolled, single-blind (patient blinded), multicenter, one-year phase 3 clinical study. The administration of amifampridine phosphate was started at 15 mg/day, and the dose was increased every 3 to 4 days to determine the optimal dose for each patient. After 7 days of treatment with the optimal dose, efficacy was assessed by evaluating quantitative myasthenia gravis (QMG), subject global impression (SGI), and Clinical Global Impression-Improvement scale (CGI-I) scores.PatientsAdult patients with LEMS were analyzed for safety [n=12, mean age±standard deviation (SD) of 61.1±14.6 years old] and efficacy (n=10, mean age±SD of 60.7±15.9 years old).ResultsIn the efficacy population, the mean±SD [median (interquartile range)] QMG score was 13.2±3.1 [13.5 (11.0, 15.0)] at baseline and 8.0±2.7 [8.0 (6.0, 9.0)] at the end of the treatment period, with a mean±SD [median (interquartile range)] change of -5.2±2.8 [-5.5 (-7.0, -3.0)]. All patients showed a decrease in the QMG score from baseline and experienced improvement in their LEMS symptoms. The SGI/CGI-I scores also improved. Efficacy was maintained until the end of the study. Five patients in the safety population experienced adverse drug reactions, the most common of which was dysesthesia (n=2).ConclusionThis study revealed the long-term efficacy and tolerability of amifampridine phosphate in Japanese adults with LEMS.

Polycythemia vera (PV) is a myeloproliferative neoplasm that is associated with an elevated risk of thrombosis. Treatment strategies are based on thrombosis risk classification. Phlebotomy is a commonly recommended treatment for all patients with PV, regardless of their risk classification, and reduces the incidence of thrombosis by lowering hematocrit levels. However, patients with PV frequently present with iron deficiency at diagnosis due to increased erythropoiesis, which repeated phlebotomy can exacerbate. This can produce symptoms that diminish quality of life, such as fatigue, lethargy, and impaired concentration. Recently, hepcidin mimetics have been developed to suppress iron utilization in erythropoiesis. Among them, rusfertide has been shown to control hematocrit levels without requiring phlebotomy. Further studies are needed to identify new treatment strategies for PV that also consider iron deficiency.

Ropeginterferon alfa-2b (Ropeg) is approved for the treatment of adults with polycythemia vera (PV). This report aims to analyze the ethnic sensitivity of Ropeg for the treatment of PV, comparing the pharmacokinetics (PK), efficacy, and safety profiles across diverse ethnic groups. We conducted a relevant review of PV and analysis of data obtained from clinical studies involving Ropeg. The PK behavior of ropeg showed no significant differences between Chinese and overseas populations. Their efficacy and safety profiles were similar across the ethnic groups. The analyses indicated that the dose-exposure-response profile of Ropeg was consistent irrespective of ethnic variations. The results suggest that Ropeg exhibits a consistent PK and pharmacodynamics profile and a similar therapeutic effect across different ethnic groups, confirming its efficacy and safety in the global treatment of PV. More generally, these findings support the broader application of Ropeg in diverse patient populations and emphasize the need for an inclusive clinical practice.

The ryanodine receptor 2 (RyR2) is present in both the heart and kidneys, and plays a crucial role in maintaining intracellular Ca2+ homeostasis in cells in these organs. This study aimed to investigate the impact of M201-A on RyR2, as well as studying its effects on cardiac and renal functions in preclinical and clinical studies. Following the administration of M201-A (1,4-benzothiazepine-1-oxide derivative), we monitored diastolic Ca2+ leak via RyR2 and intracellular Ca2+ concentration in isolated rat cardiomyocytes and in cardiac and renal function in animals. In a clinical study, M201-A was administered intravenously at doses of 0.2 and 0.4 mg·kg-1 once daily for 20 min for four consecutive days in healthy males, with the assessment of haemodynamic responses. In rat heart cells, M201-A effectively inhibited spontaneous diastolic Ca2+ leakage through RyR2 and exhibited positive lusi-inotropic effects on the rat heart. Additionally, it enhanced natriuresis and improved renal function in dogs. In human clinical studies, when administered intravenously, M201-A demonstrated an increase in natriuresis, glomerular filtration rate and creatinine clearance, while maintaining acceptable levels of drug safety and tolerability. The novel drug M201-A inhibited diastolic Ca2+ leak via RyR2, improved cardiac lusi-inotropic effects in rats, and enhanced natriuresis and renal function in humans. These findings suggest that this drug may offer a potential new treatment option for chronic kidney disease and heart failure.

ABSTRACT Objectives: Patients with myeloproliferative neoplasms (MPNs) are at higher risk of developing secondary malignancies. In this study, we focused on patients with MPNs that complicated lymphoid neoplasms. To analyze the real-world status of lymphoid neoplasm treatment in patients with pre-existing MPNs in Japan, we conducted a multicenter retrospective study. Methods: Questionnaires were sent to collect the data on patients who were first diagnosed with either polycythemia vera, essential thrombocythemia or myelofibrosis and who later were complicated with lymphoid neoplasms defined as malignant lymphoma, multiple myeloma, or chronic lymphocytic leukemia/small cell lymphoma. Results: Twenty-four patients with MPNs complicated by lymphoid neoplasms were enrolled (polycythemia vera, n = 8; essential thrombocythemia, n = 14; and primary myelofibrosis, n = 2). Among these, diffuse large B-cell lymphoma (DLBCL) was the most frequently observed (n = 13, 54.1%). Twelve (92.3%) of the patients with DLBCL received conventional chemotherapy. Among these 12 patients, regarding cytoreductive therapy for MPNs, 8 patients stopped treatment, one continued treatment, and two received a reduced dose. Consequently, most patients were able to receive conventional chemotherapy for DLBCL with a slightly higher dose of granulocyte colony-stimulating factor support than usual without worse outcomes. All 3 patients with multiple myeloma received a standard dose of chemotherapy. Conclusion: Our data indicate that if aggressive lymphoid neoplasms develop during the course of treatment in patients with MPNs, it is acceptable to prioritize chemotherapy for lymphoma.

Aims: To evaluate drug-drug interactions between carotegrast methyl, a CYP3A4 inhibitor, and other CYP3A4 substrates, midazolam, atorvastatin, and prednisolone. Methods: A total of 88 healthy volunteers orally received carotegrast methyl 960 mg three times daily for 14 days. A single oral (5 mg) or intravenous (0.017 mg kg) midazolam, oral (5 mg) prednisolone, or oral (10 mg) atorvastatin was administered before, with, and after carotegrast methyl treatment. When the 90% confidence interval (CI) for the geometric mean ratios of the pharmacokinetic (PK) parameters with coadministration with carotegrast methyl (day 14) to those before carotegrast methyl administration was between 0.80 and 1.25, no PK interaction were deemed. Results: The C and AUC of oral midazolam before administration of carotegrast methyl was 30.9 ± 9.8 ng mL and 74.5 ± 21.9 ng h mL, respectively. The geometric mean ratio of the C and AUC of midazolam on day 14 to those on day -1 was 1.86 (90% CI, 1.64 – 2.11) and 3.07 (90% CI, 2.81 – 3.35), which did not fall within the range of 0.80 – 1.25, suggesting that carotegrast methyl had a PK interaction with midazolam. Similar PK interactions were found for intravenous midazolam and atorvastatin, but not for prednisolone. The inhibitory effect of carotegrast methyl on CYP3A4-mediated metabolism of midazolam and atorvastatin had almost disappeared by 14 days after the end of administration. Conclusion: Carotegrast methyl was classified as a moderate CYP3A4 inhibitor in humans. Carotegrast methyl might enhance the action of drugs that are metabolized by CYP3A4.

BCR::ABL1-negative myeloproliferative neoplasms (MPNs) are a group of hematopoietic malignancies in which somatic mutations are acquired in hematopoietic stem/progenitor cells, resulting in an abnormal increase in blood cells in peripheral blood and fibrosis in bone marrow. Mutations in JAK2, MPL, and CALR are frequently found in BCR::ABL1-negative MPNs, and detecting typical mutations in these three genes has become essential for the diagnosis of BCR::ABL1-negative MPNs. Furthermore, comprehensive gene mutation and expression analyses performed using massively parallel sequencing have identified gene mutations associated with the prognosis of BCR::ABL1-negative MPNs such as ASXL1, EZH2, IDH1/2, SRSF2, and U2AF1. Furthermore, single-cell analyses have partially elucidated the effect of the order of mutation acquisition on the phenotype of BCR::ABL1-negative MPNs and the mechanism of the pathogenesis of BCR::ABL1-negative MPNs. Recently, specific CREB3L1 overexpression has been identified in megakaryocytes and platelets in BCR::ABL1-negative MPNs, which may be promising for the development of diagnostic applications. In this review, we describe the genetic mutations found in BCR::ABL1-negative MPNs, including the results of analyses conducted by our group.

Myelodysplastic/myeloproliferative neoplasm with ring sideroblasts and thrombocytosis (MDS/MPN-RS-T) is a rare disease, which presents with features of myelodysplastic syndromes with ring sideroblasts and essential thrombocythemia, as well as anemia and marked thrombocytosis. SF3B1 and JAK2 mutations are often found in patients, and are associated with their specific clinical features. This study was a retrospective analysis of 34 Japanese patients with MDS/MPN-RS-T. Median age at diagnosis was 77 (range, 51-88) years, and patients had anemia (median hemoglobin: 9.0g/dL) and thrombocytosis (median platelet count: 642 × 109/L). Median overall survival was 70 (95% confidence interval: 68-not applicable) months during the median follow-up period of 26 (range: 0-91) months. A JAK2V617F mutation was detected in 46.2% (n = 12) of analyzed patients (n = 26), while an SF3B1 mutation was detected in 87.5% (n = 7) of analyzed patients (n = 8). Like those with myelodysplastic syndromes or myeloproliferative neoplasms, patients often received erythropoiesis-stimulating agents and aspirin to improve anemia and prevent thrombosis. This study, which was the largest to describe the real-world characteristics of Japanese patients with MDS/MPN-RS-T, showed that the patients had similar characteristics to those in western countries.