Alemtuzumab monotherapy for T-cell prolymphocytic leukemia: an observational study in Japan.

Alemtuzumab is recommended as first-line and second-line therapies for T-cell prolymphocytic leukemia (T-PLL). This study retrospectively evaluated the efficacy and safety of alemtuzumab in nine Japanese patients with T-PLL at five participating institutions who were treated between January 2015 and August 2023. The median age at first administration of alemtuzumab was 72 years (range, 39 to 78). Two patients were treatment naïve, and seven had been treated with a median of one (range, 1 to 3) prior systemic therapy. Six patients were refractory to their most recent therapy. Three patients completed 12 weeks of treatment. The overall response rate and the complete response (CR) rate were 78% and 11%, respectively. Among the six patients who achieved a partial response, two achieved clinical CR but did not undergo bone marrow examination. One patient also achieved clinical CR but did not undergo CT or bone marrow examination for response evaluation. The median progression-free survival time was 8.1 months (95% confidence interval, 0.9 to 18.6). Three patients received readministration of alemtuzumab monotherapy after disease progression. There were no treatment-related deaths. The grade 3 or 4 nonhematologic adverse events included infusion reaction (grade 3, n = 2), cytomegalovirus reactivation (grade 3, n = 2), and pulmonary edema (grade 3, n = 1). One patient experienced Epstein‒Barr virus-positive diffuse large B-cell lymphoma 15 months after the last dose of alemtuzumab. These results confirm that the efficacy and safety of alemtuzumab monotherapy in Japanese patients are comparable to those previously reported.

Neoadjuvant Immunotherapy Effectiveness in Patients With Microsatellite Instability-High (MSI-H) Gastric Cancer.

Purpose This research work evaluates monotherapy with checkpoint inhibitors (CPI). as a neoadjuvant treatment for patients with Microsatellite Instability-High (MSI-H) locally advanced gastric cancer. Methods Here we present the results of the retrospective study from Napalkov Cancer Center over 4.5 years on patients with MSI-H locally advanced gastric cancer. A total of 566 patients were analyzed, 18 of whom were included in the research, focusing on clinical response rate, surgical pathology, 'watch and wait' strategy, and safety outcomes on an exploratory basis. Patients were assigned to four to eight neoadjuvant cycles of CPI, followed by surgery. Results The objective response to neoadjuvant CPI in patients with MSI-H gastric cancer was 77.8%. Complete response was achieved in five (27.8%) and partial response in nine (50%) patients, accordingly. Surgery was performed on 14 patients. Complete margin-free (R0) resection rates were 100%. Downstaging was observed in 12 out of 14 patients. Histopathologic complete response rates (pathologic complete response or Tumor Regression Grade-major response (TRG1)) were achieved in eight (57.1%) patients. No disease progression was detected with a median follow-up of 33.7 months (4.4-55.7 months). Clinically significant adverse events were not observed. Conclusion CPI in a neoadjuvant setting for patients with MSI-H locally advanced gastric cancer is highly effective and safe.

Clinical impacts of immunomodulator withdrawal from anti-tumor necrosis factor combination therapy in pediatric inflammatory bowel disease.

OBJECTIVES: Combination therapy consists of both anti-tumor necrosis factor (anti-TNF) and an immunomodulator (IMM) and has been shown to improve outcomes in patients with inflammatory bowel disease (IBD). This study assesses the impacts of IMM withdrawal from combination therapy to anti-TNF monotherapy in children with IBD. METHODS: This single-center retrospective cohort study included children with IBD initiated on combination therapy between 2014 and 2019 who discontinued the IMM. We evaluated whether IMM withdrawal impacts laboratory values and disease activity. Linear mixed effects models with random intercepts were used to compare differences between groups. Chi-square and Kruskal-Wallis tests were used for comparisons between patients who did and did not require subsequent escalation of therapy. RESULTS: One hundred and fifty-two patients discontinued the IMM which did not significantly affect disease activity. However, 18% of patients escalated therapy after IMM withdrawal, primarily due to low anti-TNF levels. Lower anti-TNF and higher erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) levels before IMM withdrawal were associated with subsequent escalation of therapy. Overall, there was no statistically significant effect on anti-TNF drug levels. Patients with Crohn's disease (CD) on infliximab (IFX) and methotrexate (MTX) who discontinued the IMM had an increase in mean ESR and CRP (p < 0.05). CONCLUSIONS: IMM withdrawal from anti-TNF combination therapy may be considered safe in the setting of higher anti-TNF levels and normal serum inflammatory markers. Clinicians should consider assessing anti-TNF levels and inflammatory markers after IMM withdrawal, especially in patients with CD receiving IFX who discontinued MTX.

A Comparison of Rosuvastatin Monotherapy and Rosuvastatin Plus Ezetimibe Combination Therapy in Patients With Type 2 Diabetes: A Meta-Analysis of Randomized Controlled Trials.

Type 2 diabetes mellitus is a metabolic condition where vascular inflammation and oxidative stress contribute to disease progression and associated complications. Although statins are recommended for managing dyslipidemia in diabetes, additional therapies are often required to achieve target lipid levels. This meta-analysis aimed to evaluate the efficacy of rosuvastatin monotherapy versus combination therapy with ezetimibe in patients with type 2 diabetes. A systematic literature search was conducted across multiple databases until April 2024, identifying six randomized controlled trials meeting the inclusion criteria. The meta-analysis revealed that the rosuvastatin plus ezetimibe combination resulted in significantly greater reductions in total cholesterol (mean difference, or MD: 19.49; 95% CI: 13.99 to 24.99), triglycerides (MD: 13.44; 95% CI: 2.04 to 24.85), and low-density lipoprotein cholesterol (MD: -17.68; 95% CI: 12.85 to 22.51) compared to rosuvastatin monotherapy. Conversely, rosuvastatin monotherapy achieved a greater reduction in HbA1c levels (MD: -0.11; 95% CI: -0.17 to -0.04). Subgroup analysis demonstrated that using the same dose of rosuvastatin in both groups led to more significant improvements in lipid parameters with lower heterogeneity. The findings suggest that the rosuvastatin-ezetimibe combination may be a more effective lipid-lowering strategy for patients with type 2 diabetes, though larger studies are needed to assess long-term safety and optimal dosing. Additionally, while rosuvastatin monotherapy provided modest HbA1c reductions, the clinical relevance remains uncertain, and potential risks with high-dose statins should be considered.

Monotherapy with infusion therapies - useful or not?

Infusion pump-based therapies are an effective treatment option for patients with advanced Parkinson´s disease. Achieving monotherapy with infusion-based therapies could simplify the treatment regimen, provide better medication adherence, reduce adverse events and drug interactions. This review presents the literature data on the efficacy, safety, and achievability of monotherapy with all available infusion-based therapies, including apomorphine, levodopa-carbidopa-intestinal gel (LCIG), levodopa-entacapone-carbidopa intestinal gel (LECIG), and foslevodopa-foscarbidopa (LDp/CDp). In summary, monotherapy is achievable and effective in most patients on intestinal levodopa infusion therapy and in some patients on apomorphine infusion. There is a need for further investigation of monotherapy compared to polytherapy, especially in new pump treatment options (LECIG and LDp/CDp). Future research should reveal which patients on infusion-based therapies could benefit from monotherapy, including identification of potential baseline predictors of achieving monotherapy in patients treated with specific infusion-based therapies.

Metformin Monotherapy With and Without Lifestyle Changes Affects Anthropometric Parameters, Blood Pressure, Blood Glucose, and Lipid Profile in Indian Patients With Newly Diagnosed Type 2 Diabetes.

INTRODUCTION: Type 2 diabetes mellitus (T2DM) is a consequence of insulin resistance, insulin deficiency, or both. It is usually seen in adults and is a consequence of genetic (polygenic inheritance), endogenous (obesity and or hormonal factors), and environmental factors (e.g., obesogenic environment, endocrine disrupting chemicals, stress, and medicines). The prevalence of T2DM has increased over the past few decades. South Asians, including Indians, are more prone to central adiposity and develop lifestyle diseases like T2DM at body mass index values lower than those considered normal for the Western population. Generally, the first line of treatment is metformin monotherapy with lifestyle changes in patients with T2DM. Most of the research conducted on this drug is on Western subjects. Since the Indian population has genetic differences in the site of deposition of adipose and is more prone to develop lifestyle diseases, the effect of metformin may be different in Indians. METHODS: Seventy-one (34 female, non-pregnant, non-lactating) adults with newly diagnosed T2DM were recruited in this short-duration pilot study after obtaining written informed consent. Patients regularly taking any drug were excluded, as were patients with chronic comorbidities. Treatment was initiated with metformin 500 mg OD. Lifestyle changes were recommended according to the age and physical condition of the patients. Anthropometric parameters (age, weight, height, BMI, waist-to-hip ratio (WHR), and waist-to-height ratio (WHtR)), blood pressure, glycemic status (fasting and 2 h PP glucose and HbA1c), and lipid profile of the subjects were recorded before initiating and six months after initiating metformin monotherapy with lifestyle changes. RESULTS: Small but statistically significant improvements were observed in the WHR,WHtR, blood pressure, blood glucose, and glycated hemoglobin. Although improvement was also observed in weight and lipid profile, these changes were not statistically significant. CONCLUSION: This study shows that metformin monotherapy with lifestyle changes is suitable for patients of Indian origin and results in improvement in the WHR, WHtR, blood pressure, plasma glucose, and glycated hemoglobin.

Efficacy and safety of anti-angiogenic drug monotherapy and combination therapy for ovarian cancer: a meta-analysis and trial sequential analysis of randomized controlled trials.

Background: As the development of novel anti-angiogenic drugs and the continuous evolution of guideline recommendations, the efficacy and safety of anti-angiogenic agents in ovarian cancer (OC) remains unclear. Consequently, a meta-analysis was carried out to assess the efficacy and safety of anti-angiogenic drug monotherapy and combination therapy for OC. Methods: An exhaustive literature review was performed across multiple databases, including PubMed, Embase, Web of Science, and Cochrane, encompassing all relevant randomized controlled trials (RCTs) up until 6 April 2024. The evaluation of efficacy outcomes incorporated progression-free survival (PFS), overall survival (OS), and objective response rate (ORR). Safety was assessed through the occurrence of any grade adverse events (AEs) and grade ≥3 AEs. Synthesis of the data involved the calculation of hazard ratios (HRs), relative risks (RRs), and their corresponding 95% confidence intervals (CIs) and prediction intervals (PIs). Trial sequential analysis was executed employing TSA v0.9.5.10 Beta software, STATA 12.0, and R software 4.3.1. Results: In this meta-analysis, 35 RCTs were included, encompassing 16,199 subjects in total. The overall analysis indicated that anti-angiogenic drug combination therapy significantly improved PFS (HR [95% CI] = 0.678 [0.606-0.759], 95% PI: 0.415-1.108), OS (HR [95% CI] = 0.917 [0.870-0.966], 95% PI: 0.851-0.984), and ORR (RR [95% CI] = 1.441 [1.287-1.614], 95% PI: 1.032-2.014), but also increased the incidence of grade ≥3 AEs (RR [95% CI] = 1.137 [1.099-1.177], 95% PI: 1.011-1.252). The analysis did not corroborate any benefit of anti-angiogenic monotherapy over placebo concerning PFS (HR [95% CI] = 0.956 [0.709-1.288], 95% PI: 0.345-2.645) and OS (HR [95% CI] = 1.039 [0.921-1.173], 95% PI: 0.824-1.331). However, it was observed that monotherapy with anti-angiogenic drugs did increase the incidence of any grade AEs (RR [95% CI] = 1.072 [1.036-1.109], 95% PI: 0.709-1.592). Conclusion: Our study confirmed the PFS, OS, and ORR benefits of anti-angiogenic drug combination therapy for OC patients. The efficacy results of anti-angiogenic monotherapy necessitates further evaluation as more RCTs become available. Clinicians should be vigilant of AEs when administering anti-angiogenic agents in a clinical setting.

Efficacy of tacrolimus monotherapy in primary membranous nephropathy.

Objective: The aim of this study was to observe the remission of primary membranous nephropathy (PMN) and evaluate the efficacy of tacrolimus (TAC) monotherapy for PMN in comparison with TAC combined with a low-dose glucocorticoid (GC) protocol (TAC + GC). Methods: This was tested in a prospective monocentric observational trial of 70 patients with PMN, of whom 34 received TAC (0.05-0.075 mg/kg/day) or 36 received TAC (0.05-0.075 mg/kg/day) and GC (0.3-0.5 mg/kg/day of prednisone). Results: At 3, 6, 9, and 12 months of treatment, the effective rates in the TAC group and the TAC + GC group were similar (P > 0.05). The urinary protein quantification was reduced in patients under both therapeutic protocols, and the differences in the proteinuria quantification at 3, 6, 9, and 12 months of treatment were not statistically significant between the two groups (P > 0.05). The overall incidence of adverse reactions in the TAC group was lower than that in the TAC + GC group (23.5% < 36.1%), and the difference was statistically significant (P < 0.05). Conclusion: TAC monotherapy for PMN could effectively reduce urinary protein quantification and increase serum albumin levels. Compared with TAC + GC, TAC monotherapy for PMN had no difference in efficacy and fewer incidences of adverse reactions.

Efficacy of anti-PD-1 monotherapy for recurrent or metastatic olfactory neuroblastoma.

Background: Olfactory neuroblastoma (ONB) is a rare malignant tumor of the head and neck. Due to its rarity, standard systemic therapy for this condition has yet to be established. In particular, the use of immune checkpoint inhibitors (ICIs) for the recurrent or metastatic (R/M) ONB population remains unclear. Methods: We retrospectively evaluated 11 patients with R/M ONB who received any systemic chemotherapy at two Japanese institutions (National Cancer Center Hospital East and Kyushu Medical Center) between January 2002 and March 2022 and analyzed outcomes by use of anti-PD-1 antibody (nivolumab or pembrolizumab) monotherapy. Results: Of the 11 patients, 6 received ICI (ICI-containing treatment group) and the remaining 5 were treated with systemic therapy but not including ICI (ICI-non-containing treatment group). Overall survival (OS) was significantly longer in the ICI-containing group (median OS: not reached vs. 6.4 months, log-rank p-value: 0.035). The fraction of ICI systemic therapy in the entire treatment period of this group reached 85.9%. Four patients (66.7%) in the ICI-containing treatment group experienced immune-related adverse events (irAE), with grades of 1/2. No irAE of grade 3 or more was seen, and no patient required interruption or discontinuation of treatment due to toxicity. Conclusion: ICI monotherapy appears to be effective and to contribute to prolonged survival in R/M ONB.

Cost-effectiveness analysis of bevacizumab for cerebral radiation necrosis treatment based on real-world utility value in China.

BACKGROUND: Bevacizumab shows superior efficacy in cerebral radiation necrosis (CRN) therapy, but its economic burden remains heavy due to the high drug price. This study aims to evaluate the cost-effectiveness of bevacizumab for CRN treatment from the Chinese payers' perspective. METHODS: A decision tree model was developed to compare the costs and health outcomes of bevacizumab and corticosteroids for CRN therapy. Efficacy and safety data were derived from the NCT01621880 trial, which compared the effectiveness and safety of bevacizumab monotherapy with corticosteroids for CRN in nasopharyngeal cancer patients, and demonstrated that bevacizumab invoked a significantly higher response than corticosteroids (65.5% vs. 31.5%, P < 0.001) with no significant differences in adverse events between two groups. The utility value of the "non-recurrence" status was derived from real-world data. Costs and other utility values were collected from an authoritative Chinese network database and published literature. The primary outcomes were total costs, quality-adjusted life-years (QALYs), and incremental cost-effectiveness ratio (ICER). The uncertainty of the model was evaluated via one-way and probabilistic sensitivity analyses. RESULTS: Bevacizumab treatment added 0.12 (0.48 vs. 0.36) QALYs compared to corticosteroid therapy, along with incremental costs of $ 2010 ($ 4260 vs. $ 2160). The resultant ICER was $ 16,866/QALY, which was lower than the willingness-to-pay threshold of $ 38,223/QALY in China. The price of bevacizumab, body weight, and the utility value of recurrence status were the key influential parameters for ICER. Probabilistic sensitivity analysis revealed that the probability of bevacizumab being cost-effectiveness was 84.9%. CONCLUSION: Compared with corticosteroids, bevacizumab is an economical option for CRN treatment in China.

Once-Daily Fluticasone Furoate/Vilanterol Versus Once-Daily Fluticasone Furoate in Asthma Patients Aged 5-17 Years.

BACKGROUND: Limited data exist comparing inhaled corticosteroid (ICS) plus adjunctive therapy versus ICS alone in pediatric asthma patients. OBJECTIVE: Evaluate the efficacy and safety of fluticasone furoate/vilanterol (FF/VI) versus FF in children and adolescents with asthma. METHODS: This Phase 3, randomized, double-blind, multicenter study (NCT03248128) included participants aged 5-17 years with ≥6 months' asthma history uncontrolled on ICS monotherapy. Participants received 4 weeks' open-label fluticasone propionate (100 µg) twice daily before 1:1 randomization to 24 weeks' double-blind FF (50 µg:100 µg) or FF/VI (50/25 µg:100/25 µg) once daily. Two populations with different primary endpoints were analyzed to meet United States (Week 12 weighted mean forced expiratory volume in 1 second [FEV1; 0-4 hours]; participants aged 5-17 years) and European (change from baseline pre-dose morning peak expiratory flow [ΔAM PEF] averaged over Weeks 1-12; participants aged 5-11 years) regulator requirements. RESULTS: Overall, 902 participants were randomized and treated, including 673 children aged 5-11 years. In participants aged 5-17, Week 12 weighted mean FEV1 (0-4 hours) was greater with FF/VI versus FF (difference: 0.083 L; P < .001). In participants aged 5-11, ΔAM PEF over Weeks 1-12 showed numerical improvement with FF/VI versus FF but was not statistically significant (difference: 3.2 L/minute; P = .228). No drug-related serious adverse events or deaths were reported. CONCLUSION: FF/VI significantly improved weighted mean FEV1 (0-4 hours; participants aged 5-17 years), but not ΔAM PEF (participants aged 5-11 years) versus FF. No new safety concerns were apparent.

Pancreatic cancer with liver metastasis maintaining complete response with gemcitabine monotherapy: A case report.

Pancreatic ductal adenocarcinoma (PDAC) is associated with a poor prognosis, and it has a recurrence rate of >70%, even in resectable cases. The treatment strategy for recurrent PDAC involves systemic chemotherapy, with gemcitabine (GEM) monotherapy historically serving as the standard of care. The present study describes the case of a patient with PDAC and postoperative liver metastases that maintained clinical complete remission (cCR) for >7 years following GEM monotherapy. A 63-year-old woman with upper abdominal pain was diagnosed with resectable PDAC and underwent pancreaticoduodenectomy. The patient was treated with GEM + S-1 as adjuvant chemotherapy for 6 months. Multiple liver metastases were detected 15 months post-operation and the patient was administered GEM alone. After 12 cycles, computed tomography showed cCR and GEM monotherapy was discontinued after 15 cycles. The patient has had no signs or symptoms of recurrence >7 years after the first recurrence. In addition, the present study analyzed PDAC resection specimens from four patients, including this case, to determine the expression levels of hENT1 protein in the tumor tissues. hENT1 is a transmembrane protein that acts as a nucleoside transporter and is a major mediator of GEM uptake into human cells. In the present case, hENT1 staining exhibited low frequency and weak positivity in the central region, whereas a strong positive reaction was observed in nearly all cell membranes at the invasive front of the cancer. The location, intensity, and frequency of hENT1 staining varied among cases. In conclusion, the efficacy of GEM may be predicted prior to treatment by evaluating hENT1 expression.

Inefficacy of anti-VEGF therapy reflected in VEGF-mediated photoreceptor degeneration.

Retinal neovascularization (RNV) is primarily driven by vascular endothelial growth factor (VEGF). However, current anti-VEGF therapies are limited by short half-lives and repeated injections, which reduce patient quality of life and increase medical risks. Additionally, not all patients benefit from anti-VEGF monotherapy, and some problems, such as unsatisfactory vision recovery, persist after long-term treatment. In this study, we constructed a recombinant adeno-associated virus (AAV), AAV2-SPLTH, which encodes an anti-VEGF antibody similar to bevacizumab, and assessed its effects in a doxycycline-induced Tet-opsin-VEGFA mouse model of RNV. AAV2-SPLTH effectively inhibited retinal leakage, RNV progression, and photoreceptor apoptosis in a Tet-opsin-VEGF mouse model. However, proteomic sequencing showed that AAV2-SPLTH failed to rescue the expression of phototransduction-related genes, which corresponded to reduced photoreceptor cell numbers. This study suggests that anti-VEGF monotherapy can significantly inhibit RNV to some extent but may not be enough to save visual function in the long term.

Efficacy and safety of levetiracetam vs. oxcarbazepine in the treatment of children with epilepsy: a systematic review and meta-analysis.

Background: Levetiracetam (LEV) and oxcarbazepine (OXC) are new antiseizure medications (ASMs). In recent years, OXC monotherapy is widely used in children with epilepsy; however, no consensus exists on applying LEV monotherapy among children with epilepsy. Objective: The present work focused on comparing the efficacy and safety of LEV and OXC monotherapy in treating children with epilepsy. Methods: We conducted a comprehensive search across multiple databases including PubMed, Cochrane Library, Embase, Web of Science, CNKI, Wanfang Database, VIP, and China Biology Medicine disc, covering studies from inception to August 26, 2023. We included randomized controlled trials (RCTs) and cohort studies evaluating the efficacy and safety of LEV and OXC monotherapy for treating epilepsy in children. We utilized Cochrane Risk of Bias Tool in RevMan 5.3 software for assessing included RCTs quality. In addition, included cohort studies quality was determined using Newcastle-Ottawa Scale (NOS). A random-effects model was utilized to summarize the results. Results: This meta-analysis included altogether 14 studies, including 893 children with epilepsy. LEV and OXC monotherapy was not statistical different among children with epilepsy in seizure-free rate (relative risk [RR] = 1.010, 95% confidence interval [CI] [0.822, 1.242], P > 0.05) and seizure frequency decrease of ≥50% compared with baseline [RR = 0.938, 95% CI (0.676, 1.301), P > 0.05]. Differences in total adverse reaction rate [RR = 1.113, 95% CI (0.710, 1.744), P > 0.05] and failure rate because of serious adverse reaction [RR = 1.001, 95% CI (0.349, 2.871), P > 0.05] were not statistical different between LEV and OXC treatments among children with epilepsy. However, the effects of OXC monotherapy on thyroid among children with epilepsy was statistically correlated than that of LEV (thyroid stimulating hormone: standardized mean difference [SMD] = -0.144, 95% CI [-0.613, 0.325], P > 0.05; free thyroxine: SMD = 1.663, 95% CI [0.179, 3.147], P < 0.05). Conclusion: The efficacy of LEV and OXC monotherapy in treating children with epilepsy is similar. However, OXC having a more significant effect on the thyroid than that of LEV. Therefore, LEV may be safer for children with epilepsy who are predisposed to thyroid disease than OXC. Systematic Review Registration: https://www.crd.york.ac.uk/, PROSPERO (CRD42024514016).

Monotherapy versus combination for the treatment of Stenotrophomonas maltophilia: a multicenter cohort study.

BACKGROUND: The aim of this study was to compare the safety and effectiveness of monotherapy versus combination therapy for the treatment of infections caused by S. maltophilia. METHODS: This retrospective, multicenter, cohort study included patients treated with either monotherapy or combination therapy for infections caused by S. maltophilia. Primary outcomes included overall in-hospital mortality, 30-day mortality, and clinical cure. Safety outcomes were also evaluated. Multivariable logistic regression was used as a control for confounding variables. RESULTS: A total of 407 patients were included, 330 patients received monotherapy and 77 patients received combination therapy. A total of 21% presented with concomitant bacteremia. After adjusting the differences between the two groups, there were no statistically significant differences between patients who received monotherapy versus combination therapy in clinical cure (55% vs 65%; OR, 0.72; 95% CI, 0.40-1.31) and overall in-hospital mortality (52% vs 49%; OR, 0.84; 95% CI, 0.45-1.57). However, patients who received monotherapy had a lower rate of 30-day mortality (28% vs 32%; OR, 0.45; 95% CI, 0.22-0.90) and acute kidney injury (9% vs 18%; OR, 0.35; 95% CI, 0.16-0.78). CONCLUSION: Clinical outcomes did not significantly differ in patients who received combination therapy versus monotherapy. More data are needed to validate these findings.

Ceftazidime-avibactam combination therapy versus monotherapy for treating carbapenem-resistant gram-negative infection: a systemic review and meta-analysis.

BACKGROUND: This meta-analysis was conducted to compare the efficacy of ceftazidime-avibactam combination therapy with that of monotherapy in the treatment of carbapenem-resistant Gram-negative bacterial (CR-GNB). METHODS: A literature search of PubMed, Embase, the Cochrane Library, and ClinicalTrials.gov was conducted until September 1, 2023. Only studies that compared CZA combination therapy with monotherapy for CR-GNB infections were included. RESULTS: A total of 25 studies (23 retrospective observational studies and 2 prospective studies) involving 2676 patients were included. There was no significant difference in 30-day mortality between the study group receiving combination therapy and the control group receiving monotherapy (risk ratio [RR] 0.91; 95% confidence interval [CI] 0.71-1.18). In addition, no significant differences were observed between the study and the control group in terms of in-hospital mortality (RR 1.00; 95% CI 0.79-1.27), 14-day mortality (RR 1.54; 95% CI 0.24-9.91), 90-day mortality (RR 1.18; 95% CI 0.62-2.22), and clinical cure rate (RR 0.95; 95% CI 0.84-1.08). However, the combination group had a borderline higher microbiological eradication rate than the control group (RR 1.15; 95% CI 1.00-1.32). CONCLUSIONS: Compared to monotherapy, CZA combination therapy did not yield additional clinical benefits. However, combination therapy may be associated with favorable microbiological outcomes.