---
title: "Isavuconazole safety and QTc trajectories in Japanese hematologic patients: longitudinal real-worl"
id: "plos-one-5-longitudinal-changes-in-laboratory-parameters-and-qtc-during-isavuconazole"
canonical_url: "https://medichelpline.com/clinical-feed/plos-one-5-longitudinal-changes-in-laboratory-parameters-and-qtc-during-isavuconazole"
content_type: "clinical_feed_article"
specialty: "Infectious Disease"
source_name: "PLOS ONE (Medicine)"
source_url: "https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0354816"
published_at: "2026-07-29T14:00:00.000Z"
evidence_level: "Journal Feed"
license: "CC-BY-NC-4.0 / Informational Use"
---
# Isavuconazole safety and QTc trajectories in Japanese hematologic patients: longitudinal real-worl
## Provenance & Clinical Metadata
- **Canonical URL:** https://medichelpline.com/clinical-feed/plos-one-5-longitudinal-changes-in-laboratory-parameters-and-qtc-during-isavuconazole
- **Specialty:** [Infectious Disease](https://medichelpline.com/clinical-feed/infectious-disease.md)
- **Primary Source:** PLOS ONE (Medicine)
- **Source URL:** [Original Journal Publication](https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0354816)
- **Published At:** 2026-07-29T14:00:00.000Z
- **Evidence Rating:** Journal Feed
## Executive GIST (TL;DR)
- This retrospective single-center study evaluated 45 consecutive Japanese patients with hematologic malignancies who received **isavuconazole (ISCZ)** between April 1, 2023 and March 31, 2025 at Gifu University Hospital. Data were extracted from electronic medical records. - The primary focus was longitudinal monitoring of laboratory parameters (hepatic and renal markers) and electrocardiographic QTc intervals (QTcB and QTcF) during ISCZ therapy. - Grade ≥2 elevations in **AST** occurred in 11.1% of patients and in **ALT** in 13.3% of patients; these transaminase increases were transient and did not reflect sustained hepatic deterioration. - Overall, linear mixed-effects modelling found no significant worsening of laboratory parameters (hepatic or renal) associated with ISCZ across the cohort. - An exploratory subgroup analysis examined patients receiving **arsenic trioxide (ATO)**: QTc trajectories were compared among ATO alone, ATO plus ISCZ (ATO‑ISCZ), and ATO with other antifungals. - In the ATO subgroup, QTc values in the ATO‑ISCZ group were lower than in the ATO-only group from Day 30 onward; the largest differences occurred at Day 70 (QTcB −45.5 ms; QTcF −42.3 ms; both p < 0.001). - The ATO with other antifungals subgroup showed QTc trends similar to the ATO-only group; no QTc shortening comparable to ATO‑ISCZ was reported for those agents. - No clinically significant cardiac events were observed in the overall cohort during ISCZ therapy. - The authors conclude that ISCZ displayed a favorable safety profile in this Japanese hematologic population and may be a safe antifungal option when co-administered with QT‑prolonging therapies such as ATO. - The study is limited by its retrospective design, single-center setting, and relatively small sample size; supporting data are provided as de-identified S1 Data in the publication.
## Clinical Analysis & Structured Key Points
Longitudinal changes in laboratory parameters and QTc during isavuconazole therapy in Japanese patients with hematologic malignancies | PLOS One Browse Subject Areas ? Click through the PLOS taxonomy to find articles in your field. For more information about PLOS Subject Areas, click here . Article Authors Metrics Comments Media Coverage Peer Review Reader Comments Figures Figures Abstract Background Isavuconazole (ISCZ) is an azole antifungal with a low risk of QTc prolongation and no requirement for renal dose adjustment. However, real-world data in Asian patients remain limited. Methods We retrospectively evaluated 45 patients who received ISCZ between April 2023 and March 2025. Laboratory parameters and QTc values (QTcB/QTcF) were extracted from medical records. Longitudinal changes were assessed using linear mixed-effects models. In patients receiving arsenic trioxide (ATO), QTc trajectories were compared among ATO alone, ATO with ISCZ (ATO-ISCZ), and ATO with other antifungals. Results Grade ≥2 elevations in AST and ALT occurred in 11.1% and 13.3% of patients, respectively, and were transient. No significant deterioration in laboratory parameters was observed. In the ATO subgroup, QTc values in the ATO-ISCZ group were lower than those in the ATO group from Day 30, with the largest difference at Day 70 (−45.5 ms for QTcB and −42.3 ms for QTcF; both p < 0.001). The ATO–other antifungals group showed similar trends to the ATO group. No clinically significant cardiac events were observed. Conclusions ISCZ showed a favorable safety profile in Japanese patients with hematologic malignancies and may be a safe option during QT-prolonging therapies. Citation: Ohata K, Kobayashi R, Watanabe D, Yamada Y, Niwa T, Wada M, et al. (2026) Longitudinal changes in laboratory parameters and QTc during isavuconazole therapy in Japanese patients with hematologic malignancies. PLoS One 21(7): e0354816. https://doi.org/10.1371/journal.pone.0354816 Editor: Felix Bongomin, Gulu University, UGANDA Received: May 21, 2026; Accepted: July 13, 2026; Published: July 29, 2026 Copyright: © 2026 Ohata et al. This is an open access article distributed under the terms of the Creative Commons Attribution License , which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Data Availability: The minimal de-identified dataset underlying the findings of this study is provided as Supporting Information (S1 Data). Funding: This study was supported by joint research funding from Asahi Kasei Therapeutics Corporation ( https://www.asahi-kasei.co.jp/pharma/en/ ) to Nobuhiro Kanemura and Akio Suzuki. No grant number was assigned to this funding. Asahi Kasei Therapeutics Corporation contributed to study conceptualization through its employee co-authors, Mio Wada and Momoko Ohashi. The funder had no role in data collection, data management, statistical analysis, interpretation of the results, or the decision to publish. Mio Wada and Momoko Ohashi reviewed the manuscript and provided feedback on its content; however, the original drafting and primary preparation of the manuscript were undertaken by the authors affiliated with Gifu University. Competing interests: Koichi Ohata has received honoraria from Chugai Pharmaceutical Co., Ltd., AbbVie GK, Meiji Seika Pharma Co., Ltd., and Genmab K.K. Yuto Kaneda has received honoraria from AbbVie GK, and Novartis Pharma K.K. Yoshikazu Ikoma has received honoraria from Meiji Seika Pharma Co., Ltd., AbbVie GK, Nippon Shinyaku Co., Ltd., Chugai Pharmaceutical Co., Ltd., and MSD K.K. Nobuhiko Nakamura has received honoraria from Chugai Pharmaceutical Co., Ltd., AbbVie GK, Kyowa Kirin Co., Ltd., Sanofi K.K., BeOne Medicines GK, Nippon Shinyaku Co., Ltd., Genmab K.K., Janssen Pharmaceutical K.K., Daiichi Sankyo Company, Limited, Takeda Pharmaceutical Company Limited, Nippon Kayaku Co., Ltd., AstraZeneca K.K., Sumitomo Pharma Co., Ltd., and Meiji Seika Pharma Co., Ltd. Akio Suzuki has received research funding from Mochida Pharmaceutical, Japan Blood Products Organization, Chugai Pharmaceutical Co., Ltd., and Nippon Kayaku Co., Ltd., and honoraria for presentations and expert testimony from Tsumura, Daiichi Sankyo Company, Limited, Towa Pharmaceutical, Nippon Kayaku Co., Ltd., Mochida Pharmaceutical, EA Pharma, Yakult Honsha, Chugai Pharmaceutical Co, AbbVie GK, Eisai, and Toa Eiyo. The other authors declare no conflicts of interest related to this study. Introduction Invasive fungal infections (IFIs) are serious complications associated with high mortality in patients with hematologic malignancies who undergo intensive chemotherapy or immunosuppressive therapy, particularly those with prolonged neutropenia or graft-versus-host disease (GVHD) after allogeneic hematopoietic stem cell transplantation (HSCT) [ 1 , 2 ]. Therefore, appropriate prophylaxis and early treatment of IFIs are crucial for improving clinical outcomes in this population [ 3 ]. Isavuconazole is a broad‑spectrum triazole antifungal agent whose prodrug, isavuconazonium sulfate, is approved for the treatment of invasive aspergillosis and mucormycosis [ 4 , 5 ]. Hereafter, we refer to both forms collectively as ISCZ. ISCZ has several clinically favorable properties: it is available in both intravenous and oral formulations, and its high oral bioavailability facilitates switching from intravenous to oral therapy [ 6 , 7 ]. In addition, ISCZ does not generally require therapeutic drug monitoring (TDM) [ 8 , 9 ], in clear contrast to voriconazole (VRCZ), for which TDM is recommended due to its nonlinear pharmacokinetics [ 10 , 11 ]. ISCZ is not primarily eliminated via the renal route, and dose adjustment is not required in patients with renal impairment. Moreover, it appears to carry a lower risk of drug–drug interactions than other azoles [ 12 , 13 ]. Another important characteristic of ISCZ is its absence of a clinically relevant risk of QTc interval prolongation, a common concern with VRCZ and other azoles. In a thorough QT study, ISCZ did not demonstrate concentration-dependent QTc prolongation [ 14 ]. In fact, pooled analyses of clinical trial datasets and real-world evidence have shown that ISCZ is associated with QTc shortening rather than prolongation [ 14 , 15 ]. Based on this unique profile, it has been suggested that ISCZ can be used safely even in patients with pre-existing QTc prolongation [ 16 ]. In contrast, several antineoplastic agents frequently used in the treatment of hematologic malignancies, such as arsenic trioxide (ATO), are known to prolong the QT interval and increase the risk of ventricular arrhythmias [ 17 – 19 ]. Accordingly, ISCZ may offer a clinically meaningful advantage from a cardiovascular safety standpoint on co-administration with QT-prolonging agents. However, real-world data on ISCZ use in Asian populations, including Japanese patients, remain limited. Most available evidence comes from international phase 3 trials [ 4 , 5 ] and a specific Japanese phase 3 study [ 20 ]. Although retrospective real-world reports in Asian patients with hematologic diseases have begun to emerge [ 21 , 22 ], these studies are restricted by relatively small sample sizes and specific patient populations. In particular, data on the impact of ISCZ on QTc interval in patients receiving ATO-containing regimens are markedly limited. The present study aimed to retrospectively evaluate the clinical use and safety of ISCZ in patients treated at the Department of Hematology and Infectious Diseases, Gifu University Hospital. We specifically focused on longitudinal changes in laboratory parameters reflecting hepatic and renal function, as well as QTc interval dynamics. In addition, we also explored QTc changes in patients receiving high-risk ATO-containing regimens with and without concomitant ISCZ. Methods Patients This retrospective study included 45 consecutive patients who received ISCZ at the Department of Hematology and Infectious Diseases, Gifu University Hospital, between April 1, 2023, and March 31, 2025. Data were obtained from electronic medical records. Patients aged <18 years and those in whom ISCZ was discontinued within 3 days of initiation, making safety evaluation difficult, were excluded. The primary objective of this study was to evaluate the clinical use and safety of ISCZ in real-world practice, with a focus on longitudinal changes in laboratory parameters. Additionally, to investigate the impact of ISCZ on drug-induced QTc prolongation, we exploratorily assessed QTc trajectories in patients receiving high-risk ATO-containing regimens by comparing those with and without concomitant ISCZ. Data collection The following data were collected: patient demographics (age, sex), underlying hematologic malignancy, history of HSCT, Eastern Cooperative Oncology Group Performance Status (ECOG PS), route of administration, and duration of ISCZ therapy. Laboratory parameters collected during ISCZ therapy included aspartate aminotransferase (AST), alanine aminotransferase (ALT), total bilirubin (T-Bil), γ-glutamyl transferase (γ-GTP), alkaline phosphatase (ALP), lactate dehydrogenase (LDH), serum creatinine (Cre), neutrophil count (Neut), white blood cell count (WBC), platelet count (PLT), hemoglobin (HGB), sodium (Na), potassium (K), and chloride (CL). Electrocardiogram (ECG) findings, specifically QTc intervals, were also collected. Laboratory abnormalities were graded according to the Common Terminology Criteria for Adverse Events (CTCAE), version 5.0. Data used in the final analysis were extracted from the electronic medical records for research purposes between February 4, 2025, and March 19,2026. Assessment of QTc interval QTc intervals were obtained from standard 12-lead ECGs recorded using hospital ECG systems, and automated QTc values calculated by the device’s built-in algorithm were used for analysis. Baseline QTc was defined as the ECG measurement performed at the start of an ATO-containing regimen. During treatment, all ECGs performed at the discretion of the treating physician were reviewed, and QTc values recorded during periods of ATO administration were included in the analysis. To assess the impact of different antifungal strategies on QTc dynamics during high-risk therapy, we evaluated 17 patients who received ATO-containing regimens, including the 4 patients in the ISCZ treatment cohort (n = 45) who received concomitant ATO. Because the status of concomitant antifungal therapy could change over time within an individual patient, each observation point was categorized into one of the following three groups based on the therapy administered at the time of the ECG, namely (1) ATO alone; (2) ATO with concomitant ISCZ (ATO-ISCZ); or (3) ATO with other concomitant antifungals, including itraconazole, fluconazole, voriconazole, or micafungin with or without liposomal amphotericin B (ATO-other antifungals). The longitudinal distribution and transitions of these treatment statuses are illustrated in Fig 1 . All available QTc values recorded during periods of ATO administration were included in the linear mixed-effects model analysis, which appropriately accounted for these time-varying covariates. Download: PNG larger image TIFF original image Fig 1. Longitudinal distribution of treatment status. Stacked bar chart showing the proportions of the three treatment groups (ATO alone, ATO-ISCZ, and ATO-other antifungals) among 17 patients over the course of arsenic trioxide therapy. The numbers below the x-axis indicate the total number of patients e.valuated at each time point. Abbreviations: ATO, arsenic trioxide; ISCZ, isavuconazole. https://doi.org/10.1371/journal.pone.0354816.g001 Statistical analysis Continuous variables are presented as the median (range) or median (interquartile range), and categorical variables as numbers (%). Longitudinal changes in laboratory parameters during ISCZ therapy, as well as QTc intervals among the three groups defined in Section 2.3, were evaluated using linear mixed-effects models, accounting for repeated measurements within individuals. Random-intercept models were applied, with individual patients treated as random effects. For descriptive visualization of QTc dynamics, changes from baseline were calculated for each patient, and individual trajectories were visualized as spaghetti plots against days since treatment initiation. QTc analyses were performed using the observed QTc values (QTcB and QTcF) as outcome variables. To account for potential non-linear trajectories in patients receiving ATO-containing regimens, time (days) was modeled using a restricted cubic spline with four knots in a linear mixed-effects model. In these models, treatment group, time (modeled as a spline), and their interaction were included as fixed effects, with baseline QTc and ATO exposure (yes/no) at each measurement occasion included as a covariate for adjustment. Group-specific trajectories were visualized based on the predicted values from these non-linear models. Furthermore, to quantify the differences between groups at specific time points, estimated marginal means were calculated, and pairwise comparisons between the ATO group and other two groups were performed at 10-day intervals (from day 10–100) using Tukey adjustment within each time point. A two-sided p value of < 0.05 was considered statistically significant. Statistical analyses were performed using EZR (Saitama Medical Center, Jichi Medical University) [ 23 ] and R (version 4.5.1; The R Foundation for Statistical Computing) [ 24 ]. Ethical considerations This study was approved by the Ethics Committee of the Graduate School of Medicine, Gifu University (approval number: 2024−272). Owing to the retrospective observational design using existing medical records, the requirement for written informed consent was waived by the ethics committee. Information regarding the study was made publicly available, and patients were given the opportunity to opt out in accordance with institutional policies. The data were handled in a de-identified manner, and analyses were conducted after removal of directly identifiable personal information. Results Patient characteristics A total of 45 patients who received ISCZ during the study period were included in the analysis. Underlying hematologic malignancies included acute myeloid leukemia, acute lymphoblastic leukemia, non-Hodgkin lymphoma, and myelodysplastic syndrome, among others ( Table 1 ). Among patients who underwent hematopoietic stem cell transplantation, the largest group consisted of patients who received allogeneic hematopoietic stem cell transplantation (HSCT). ISCZ was used for the treatment of both documented or suspected IFI and for prophylaxis in high-risk patients. All patients received oral ISCZ. Download: PNG larger image TIFF original image Table 1. Patient characteristics. https://doi.org/10.1371/journal.pone.0354816.t001 Longitudinal changes in laboratory parameters During ISCZ therapy, CTCAE grade ≥ 2 elevations in liver enzymes were observed in 11.1% (5/45) patients for AST and 13.3% (6/45) for ALT. These abnormalities were transient in all cases, and ISCZ could be continued in all cases without dose modification. Linear mixed-effects modeling revealed no evidence of a unidirectional and clinically meaningful deterioration over time in any of the evaluated parameters, including hepatic markers (AST, ALT, T-Bil, γ-GTP, ALP, LDH), renal function (Cre), or electrolytes (Na, K, CL) ( Fig 2 ). Even among patients who already had abnormal hepatic or renal function at the start of ISCZ therapy, follow-up values were generally similar to or lower than baseline values, and no clear signal suggesting ISCZ-associated worsening of hepatic or renal function was seen. Download: PNG larger image TIFF original image Fig 2. Longitudinal trajectories of clinical laboratory parameters during isavuconazole therapy. The solid lines represent the estimated marginal means derived from linear mixed-effects models, with shaded areas indicating 95% confidence intervals. Linear mixed-eTheffects modeling revealed no evidence of a unidirectional and clinically meaningful deterioration over time in any of the evaluated parameters, including hepatic markers (AST, ALT, T-Bil, γ-GTP, ALP, LDH), renal function (Cre), or electrolytes (Na, K, CL). The dashed red lines represent the baseline value (zero change), and scatter plots show individual data points for the 45 patients. https://doi.org/10.1371/journal.pone.0354816.g002 QTc interval dynamics Individual longitudinal changes in QTcB and QTcF are presented as spaghetti plots in Fig 3 . In the ATO alone group and ATO-other antifungals group, a tendency toward QTc prolongation from baseline was observed in many patients. In contrast, in the ATO-ISCZ group, while some patients exhibited transient increases in QTc intervals, many trajectories remained stable or demonstrated negative changes (shortening) throughout the observation period. These observations were quantified using a multivariable linear mixed-effects model with restricted cubic splines ( Fig 4 ). Quantitative comparisons using estimated marginal means are shown in Table 2 . Analysis revealed that the ATO–ISCZ group exhibited significantly lower QTc values compared with the ATO group starting from Day 30 (QTcB difference: −29.6 ms, 95% CI [−47.4 to −11.9], p < 0.001; QTcF difference: −31.2 ms, 95% CI [−47.3 to −15.1], p < 0.001). The shortening effect was most pronounced at Day 70, with an estimated difference of −45.5 ms for QTcB (95% CI [−67.2 to −23.8], p < 0.001) and −42.3 ms for QTcF (95% CI [−64.2 to −20.4], p < 0.001). Furthermore, significantly shorter intervals in the ATO-ISCZ group were maintained at Day 90 (QTcB difference: −40.6 ms, p < 0.001; QTcF difference: −35.4 ms, p = 0.004). Download: PNG larger image TIFF original image Fig 3. Individual longitudinal changes in QTcB and QTcF intervals under ATO-containing regimens. Longitudinal changes from baseline in (a) QTcB and (b) QTcF intervals are shown for individual patients, stratified by treatment group: ATO, ATO-ISCZ and ATO-other antifungals. Each line represents an individual patient’s trajectory. The red dashed lines indicate baseline (zero change). https://doi.org/10.1371/journal.pone.0354816.g003 Download: PNG larger image TIFF original image Fig 4. Predicted trajectories of QTcB and QTcF intervals based on non-linear mixed-effects modeling. Estimated marginal means for (a) absolute QTcB values and (b) absolute QTcF values over time, modeled using restricted cubic splines with four knots to account for non-linear dynamics. Predicted values are adjusted for baseline levels. Patients are stratified into three treatment groups: ATO alone (red lines), ATO-ISCZ (green lines), and ATO-other antifungal agents (blue lines). Shaded areas represent 95% confidence intervals. https://doi.org/10.1371/journal.pone.0354816.g004 Download: PNG larger image TIFF original image Table 2. Estimated differences in QTc intervals relative to the ATO group. https://doi.org/10.1371/journal.pone.0354816.t002 In contrast, the ATO–other antifungals group showed no significant difference from the arsenic trioxide alone group at any time point, with trajectories often trending toward prolongation. Additionally, the ATO treatment groups showed no clinically significant cardiac events, including torsades de pointes, symptomatic ventricular arrhythmias, or sudden cardiac death, regardless of the type of concomitant antifungal therapy. Discussion In this study, we found that QTc intervals remained at relatively shorter levels in the ISCZ co-administration group compared to the arsenic trioxide (ATO) alone group, even under exposure to ATO, which carries a high risk of QT prolongation. We also found that liver function abnormalities during ISCZ therapy were infrequent and transient, with CTCAE grade
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