菊地 佳代子

In this clinical trial, we aimed to confirm that immunosuppressant tacrolimus could be an effective and safe treatment option for patients with unexplained refractory infertility. Trial participants were women aged between 18 and 40 with refractory infertility who did not have underlying factors despite appropriate infertility evaluation and did have a Th1-dominant cytokine pattern defined as a Th1/Th2 cell ratio ≥ 10.3 in peripheral blood. Patients were randomly assigned (2:1 ratio) to receive immunosuppressive therapy with tacrolimus at a daily dose of 2 (low dose) or 4 (high dose) mg. Tacrolimus was orally administered for 16 days, starting 2 days before embryo transfer. The primary efficacy outcome was the presence of clinical pregnancy 3 weeks after embryo transfer. The clinical pregnancy proportion in the low- and high-dose groups was tested against the assumed proportion of 5% in the untreated group using a one-sided exact binomial test with a significance level of 0.0125. In the full analysis set, the proportion of clinical pregnancy at 3 weeks after embryo transfer was 66.7% (95% CI, 38.4-88.2) and 55.6% (95% CI, 21.2-86.3) in the low- and high-dose groups, respectively (p < 0.0001 for both). Immunosuppressive therapy with tacrolimus is a viable treatment option for patients with infertility who exhibit a Th1-dominant cytokine pattern without underlying factors.

BACKGROUND: Although the number of frozen-thawed blastocysts transfer is increasing worldwide, the live birth rate following blastocyst transfer using assisted reproductive technology remains at 30-60%. Thus, improving the pregnancy rate per transfer is an urgent issue. In a previous retrospective study, we evaluated the use of granulocyte-macrophage colony-stimulating factor (GM-CSF)-containing medium for recovery culture to improve the outcomes of frozen-thawed blastocyst transfers. The results demonstrated that the live birth rates increased by approximately 10% following recovery culture in the GM-CSF-containing culture medium. This study aims to prospectively evaluate whether GM-CSF-containing blastocyst recovery culture following thawing increases live birth. METHODS: This is a multicenter, randomized, parallel-group, active-controlled, single-blind trial. The recruitment target is 750 participants meeting the criteria. Enrolled patients are randomized 1:1 to the GM-CSF-containing culture medium group (test group) or the non-GM-CSF-containing culture medium group (control group). The blastocyst recovery culture after warming was defined as an intervention in this study; frozen-thawed blastocysts will be cultured for 3-7 h in GM-CSF-containing medium (test group) or medium without GM-CSF (control group) followed by blastocyst transfer. The primary outcome will be live birth. We will also evaluate embryo transfer outcomes as secondary efficacy endpoints and evaluate perinatal and neonatal outcomes as a safety endpoint. DISCUSSION: This is the first large-scale prospective study to investigate the efficacy of a GM-CSF-containing medium for frozen-thawed blastocyst transfer. The study findings will provide evidence regarding the efficiency of GM-CSF-containing medium for blastocyst recovery culture after warming. TRIAL REGISTRATION: Japan Registry of Clinical Trials jRCT1040240159. Registered on January 6, 2025.

BACKGROUND: Cisplatin-induced nephrotoxicity (CIN) is a major dose-limiting adverse event that can lead to both acute and chronic kidney injury. The formation of thiol-cisplatin conjugates within renal tubular cells has been implicated as a key mechanism underlying CIN. Flopropione is an inhibitor of cysteine conjugate β-lyase 1, an enzyme that catalyzes the formation of the thiol-cisplatin conjugate, which might prevent CIN. OBJECTIVE: We designed a clinical trial to evaluate the safety of flopropione in patients receiving cisplatin-based chemotherapy and explore its efficacy in preventing CIN. METHODS: This is a phase 1 and 2a, single-center, randomized, open-label trial conducted in patients undergoing cisplatin therapy. Participants are randomized in a 5:2 ratio per cohort to receive either flopropione or no treatment. On the day of cisplatin administration, the flopropione group receives oral flopropione twice daily (80 mg in cohort 1, 160 mg in cohort 2, and 240 mg in cohort 3). On the following day, all cohorts receive 3 doses of 80 mg of oral flopropione. A step-up dose escalation design is adopted, progressing from cohort 1 to 3 after confirming safety at each level. The primary end point is the safety of flopropione use in combination with cisplatin; the secondary end points include changes in the levels of urinary biomarkers of nephrotoxicity such as neutrophil gelatinase-associated lipocalin, liver-type fatty acid-binding protein, and kidney injury molecule-1. Blood and urine samples are collected within 48 hours before cisplatin administration and at 24 hours, 48 hours, and 1 week after its initiation for safety and efficacy assessments. RESULTS: The first participant was registered in July 2024. As of January 2026, participant registration is ongoing. The final participant will complete the study by March 2026. Publication of results is expected by March 2027. CONCLUSIONS: This study is expected to contribute to advances in preventive strategies for CIN by providing evidence that inhibition of cysteine conjugate β-lyase 1 by flopropione may attenuate CIN. TRIAL REGISTRATION: Japan Registry of Clinical Trials jRCTs041220021; https://jrct.mhlw.go.jp/en-latest-detail/jRCTs041220021. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/87907.

BACKGROUND: The rate of recurrent spontaneous preterm delivery (sPTD) ranges between 27% and 34% and is 22.3% in Japan. Although it currently remains unclear whether probiotics prevent sPTD, retrospective studies recently reported a reduction in the rate of recurrent sPTD with the administration of probiotics including Clostridium spp., which induce regulatory T cells that play an important role in maintaining pregnancy. OBJECTIVE: The objective of this trial is to evaluate the preventative effects of available oral probiotics, including Clostridium butyricum, on recurrent sPTD. METHODS: This is a prospective, single-arm, nonblinded, multicenter trial in Japan. The sample size required for this trial is 345 pregnant women with a history of sPTD, considering a clinically significant reduction in the relative risk of 30% (risk ratio=0.7). The primary endpoint is the rate of recurrent sPTD at <37 weeks of gestation. The secondary endpoints are the rate of sPTD at <34 weeks of gestation, the rate of recurrent sPTD at <28 weeks of gestation, the ratio of intestinal Clostridium spp. (detected by next-generation sequencing), and bacterial vaginosis (using the Nugent score). RESULTS: The trial procedures were approved by the Clinical Research Review Board of Toyama University Hospital (SCR2020008) on March 31, 2021. The trial was registered on the Japan Registry of Clinical Trial website on April 28, 2021. Recruitment began on May 1, 2021, and the trial is estimated to finish on March 31, 2025. CONCLUSIONS: The findings will clarify the rate of recurrent sPTD following probiotic administration including Clostridium butyricum. Outcomes from this trial will inform clinical practice and guide future randomized controlled trials. TRIAL REGISTRATION: Japan Registry of Clinical Trials jRCTs041210014; https://jrct.niph.go.jp/latest-detail/jRCTs041210014. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/59928.

Introduction: Infertility is estimated to affect 8% to 12% of reproductive-aged couples worldwide. While approximately 85% of infertile couples have an identified cause, the remaining 15% suffer physically and emotionally from unexplained intractable infertility. In recent years, maternal-to-fetal immunological abnormalities have attracted attention as mechanisms that differ from the conventional factors contributing to infertility and pregnancy loss. A T-helper 2 (Th2)-dominant immune state has been proposed as a maternal immune alteration to eliminate rejection and induce tolerance to a semi-allogeneic fetus. An imbalance in Th1 responses would not induce adequate maternal immune tolerance to the fetus or early embryos. Tacrolimus, widely used as an immunosuppressant agent in solid organ transplant recipients, is expected to suppress maternal rejection and promote tolerance to early embryos after assisted reproductive technology by modulating the immunological environment of the preimplantation endometrium. We planned an exploratory clinical trial to determine the efficacy, safety, and dosage of tacrolimus in women with intractable infertility. Methods and analysis: This is a multicenter, 2-dose, single-group controlled trial in infertile women who failed to achieve a chemical pregnancy despite multiple in vitro fertilization (IVF) and embryo transfer (ET) treatment cycles. The following 2 key selection criteria were set: no underlying factors of infertility despite appropriate evaluation and presence of Th1-dominant immune state, defined as a Th1/Th2 cell ratio ≥ 10.3 in the peripheral blood. A total of 26 eligible participants are randomly assigned (in a 2:1 ratio) to receive immunosuppressive therapy with oral tacrolimus at a daily dose of 2 mg or 4 mg. Tacrolimus is administered for 16 days starting from 2 days before ET. The primary endpoint is the presence of clinical pregnancy 3 weeks after IVF/ET treatment, and the secondary endpoint is the presence of biochemical pregnancy 2 weeks after IVF/ET treatment. Safety evaluation and biomarker discovery for tacrolimus treatment in infertile women will be conducted simultaneously. Trial registration number: Japan Registry of Clinical Trials (jRCT; jRCTs031220235).