HIV-1 resistance and virological failure to treatment with the integrase inhibitors bictegravir, cabotegravir, and dolutegravir: a systematic literature review.

We describe and analyze resistance-associated mutations (RM) and virological failures (VF) on antiretroviral therapy using the latest approved integrase inhibitors (INIs) dolutegravir (DTG), bictegravir (BIC), and cabotegravir (CAB), together with their companion drugs in fixed-dose formulations: BIC/emtricitabine/tenofovir; CAB/rilpivirine; DTG/abacavir/lamivudine; DTG/emtricitabine/tenofovir; and DTG/lamivudine. Systematic literature searches were conducted in PubMed and other electronic databases for clinical studies published between January 2010 and May 2023, according to preferred reporting items for systematic reviews and meta-analyses guidelines (PRISMA), which analyzed VFs and RMs of INIs. Fifty clinical studies were included in the synthesis. VF in antiretroviral treatment (ART)-naïve patients occurred in 0.7-4.0%, 0.6-1.4%, and 0.6-9.0% of patients treated with DTG, BIC, and CAB, respectively. VF was reported in patients with previous ART in 0-8.1%, 0-2.0%, and 0.4-2.3% of those treated with DTG, BIC, and CAB, respectively. RMs were detected in ART-naïve patients in only one study with DTG (0.3%), none of the studies with BIC, and three of the studies with CAB (0.1-5.4%). In ART-experienced patients, RMs were detected in 0-1.9% of DTG-treated patients. No cases of RM were detected in the 11 BIC studies reviewed. In the case of CAB, RMs were detected in eight studies, ranging from 0.3% to 1.9% of patients. In conclusion, RM rates in the studies reviewed were generally low using the latest INIs. This review identified BIC as the INI with the lowest number of observed VF and lack of RM.

Removing the FDA's Boxed Hepatotoxicity Warning and Liver Function Testing Requirement for Ambrisentan.

Importance: Endothelin receptor antagonists are first-line therapy for pulmonary arterial hypertension (PAH). The first 2 agents approved in the class, bosentan and ambrisentan, initially carried boxed warnings for hepatotoxicity and required monthly liver function tests (LFTs) as part of a risk evaluation and mitigation strategy (REMS); however, in 2011, as further safety data emerged on ambrisentan, the boxed hepatotoxicity warning and LFT requirements were removed. Objective: To analyze changes in the use of and LFT monitoring for ambrisentan and bosentan after changes to the ambrisentan labeling and REMS. Design, Setting, and Participants: This serial cross-sectional study used data from 3 longitudinal health care insurance claims databases-Medicaid, Optum's deidentified Clinformatics Data Mart, and Merative Marketscan-to perform an interrupted time series analysis of prescription fills and LFTs for patients taking ambrisentan and bosentan. Participants were patients filling prescriptions for ambrisentan and bosentan from July 1, 2007, to December 31, 2018. Data analysis was performed from April 2021 to August 2023. Exposure: Removal of the boxed warning for hepatotoxicity and the REMS LFT monitoring requirements on ambrisentan in March 2011. Main Outcomes and Measures: The primary outcomes were use of ambrisentan (ie, individuals with at least 1 dispensing per 1 000 000 individuals enrolled in the 3 datasets) vs bosentan and LFT monitoring (ie, proportion of initiators with at least 1 ordered test) before initiation and before the first refill. Results: A total of 10 261 patients received a prescription for ambrisentan during the study period (7442 women [72.5%]; mean [SD] age, 52.6 [17.6] years), and 11 159 patients received a prescription for bosentan (7931 women [71.1%]; mean [SD] age, 47.7 [23.7] years). Removal of the ambrisentan boxed hepatotoxicity warning and LFT monitoring requirement was associated with an immediate increase in the use of ambrisentan (1.50 patients per million enrollees; 95% CI, 1.08 to 1.92 patients per million enrollees) but no significant change in the use of bosentan. There were reductions in recorded LFTs before drug initiation (13.1% absolute decrease; 95% CI, -18.2% to -8.0%) and before the first refill (26.4% absolute decrease; 95% CI, -34.4% to -18.5%) of ambrisentan but not bosentan. Conclusions and Relevance: In this serial cross-sectional study of ambrisentan, labeling changes and removal of the REMS-related LFT requirement were associated with shifts in prescribing and testing behavior for ambrisentan but not bosentan. Further clinician education may be needed to maximize the benefits of REMS programs and labeling warnings designed to ensure the safe administration of high-risk medications.

Effect of ambrisentan in patients with systemic sclerosis and mild pulmonary arterial hypertension: long-term follow-up data from EDITA study.

BACKGROUND: In the EDITA trial, patients with systemic sclerosis (SSc) and mild pulmonary vascular disease (PVD) treated with ambrisentan had a significant decline of pulmonary vascular resistance (PVR) but not of mean pulmonary arterial pressure (mPAP) vs. placebo after six months. The EDITA-ON study aimed to assess long-term effects of open label therapy with ambrisentan vs. no pulmonary arterial hypertension (PAH) therapy. METHODS: Patients who participated in the EDITA study and received regular follow-up were included in EDITA-ON. Clinical, echocardiographic, laboratory, exercise and hemodynamic parameters during follow-up were analysed. The primary endpoint was to assess whether continued treatment with ambrisentan vs. no treatment prevented the development of PAH according to the new definition. RESULTS: Of 38 SSc patients included in the EDITA study four were lost to follow-up. Of the 34 remaining patients (age 55 ± 11 years, 82.1% female subjects), 19 received ambrisentan after termination of the blinded phase, 15 received no PAH medication. The mean follow-up time was 2.59 ± 1.47 years, during which 29 patients underwent right heart catheterization. There was a significant improvement of mPAP in catheterised patients receiving ambrisentan vs. no PAH treatment (-1.53 ± 2.53 vs. 1.91 ± 2.98 mmHg, p = 0.003). In patients without PAH treatment 6/12 patients had PAH vs. 1/17 of patients receiving ambrisentan (p < 0.0001). CONCLUSION: In SSc patients with early PVD, the development of PAH and/or deterioration was less frequent among patients receiving ambrisentan, indicating that early treatment and close follow-up could be beneficial in this high-risk group. Future trials in this field are needed to confirm these results.

Levosimendan: efficacy and safety in pediatric heart failure treatment.

OBJECTIVE: The objective of this study was to assess the effectiveness and safety of levosimendan as an alternative treatment for pediatric patients with decompensated heart failure unresponsive to conventional inotropes and to emphasize its role in enhancing cardiovascular stability. METHODS: A total of 15 pediatric patients with decompensated heart failure, stemming from acute fulminant myocarditis (53.3%) and post-congenital heart disease surgery complications (46.7%), received levosimendan. The evaluation focused on adverse effects, respiratory support requirements, and concurrent inotropic medication use during levosimendan treatment. Key cardiovascular parameters were assessed at 0, 6, 12, and 24 h post-levosimendan infusion. RESULTS: Levosimendan administration significantly improved key cardiovascular metrics. Left ventricular ejection fraction increased notably from 45±14.8% to 58±15.6% at 24 h (p<0.001). Systolic and diastolic blood pressures rose significantly, with systolic increasing from 79 (68-90) to 98 (89-109) mmHg and diastolic from 47 (40-57) to 66 (54-76) mmHg by 24 h (p<0.001). Heart rate decreased from 162 (111-175) to 132 (99-148) bpm (p=0.02), and lactate levels significantly decreased from 4.15 (2.3-6.5) to 1.85 (0.8-2.6) mmol/L within 6 h (p<0.001). CONCLUSION: Levosimendan demonstrates its significance in managing pediatric heart failure, indicating its safety and potential to enhance cardiac outcomes by reducing reliance on traditional inotropes.

The therapeutic effect of levosimendan in patients with prolonged ventilator weaning and cardiac dysfunction.

OBJECTIVE: To explore the therapeutic effect of levosimendan in patients with prolonged ventilator weaning and cardiac dysfunction. METHOD: Patients with prolonged ventilator weaning and cardiac dysfunction were randomly allocated to receive conventional treatment (control group) or intravenous infusion of levosimendan for 24 h based on conventional treatment (levosimendan group). Weaning success rates were then compared between the two groups. The study was retrospectively registered with Research Registry (ID No. researchregistry10304). RESULTS: A total of 40 patients were included (20 per group). Within 3 days after initiation of treatment, significantly more cases were successfully weaned in the levosimendan group versus control group (eight versus four cases, respectively). Among the eight patients who underwent pulse indicator continuous cardiac output monitoring in the levosimendan group, the global ejection fraction increased 24 h after treatment, and the cardiac function index and cardiac index increased 72 h after treatment. CONCLUSION: For patients requiring prolonged mechanical ventilation who have concomitant cardiac dysfunction, levosimendan may be considered to increase the probability of weaning success.

BRD4 degraders may effectively counteract therapeutic resistance of leukemic stem cells in AML and ALL.

Acute myeloid leukemia (AML) and acute lymphoblastic leukemia (ALL) are life-threatening hematopoietic malignancies characterized by clonal expansion of leukemic blasts in the bone marrow and peripheral blood. The epigenetic reader BRD4 and its downstream effector MYC have recently been identified as potential drug targets in human AML and ALL. We compared anti-leukemic efficacies of the small-molecule BET inhibitor JQ1 and the recently developed BRD4 degraders dBET1 and dBET6 in AML and ALL cells. JQ1, dBET1, and dBET6 were found to suppress growth and viability in all AML and ALL cell lines examined as well as in primary patient-derived AML and ALL cells, including CD34+/CD38- and CD34+/CD38+ leukemic stem and progenitor cells, independent of the type (variant) of leukemia or molecular driver expressed in leukemic cells. Moreover, we found that dBET6 overcomes osteoblast-induced drug resistance in AML and ALL cells, regardless of the type of leukemia or the drug applied. Most promising cooperative or even synergistic drug combination effects were seen with dBET6 and the FLT3 ITD blocker gilteritinib in FLT3 ITD-mutated AML cells, and with dBET6 and the multi-kinase blocker ponatinib in BCR::ABL1+ ALL cells. Finally, all BRD4-targeting drugs suppressed interferon-gamma- and tumor necrosis factor-alpha-induced expression of the resistance-related checkpoint antigen PD-L1 in AML and ALL cells, including LSC. In all assays examined, the BRD4 degrader dBET6 was a superior anti-leukemic drug compared with dBET1 and JQ1. Together, BRD4 degraders may provide enhanced inhibition of multiple mechanisms of therapy resistance in AML and ALL.

Successful treatment of two cases with Philadelphia-chromosome positive acute lymphoblastic leukemia who relapsed after allogeneic stem cell transplantation and the treatments with novel immunotherapies and ponatinib.

The outcomes of relapsed Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ALL) resistant to new drugs such as tyrosine kinase inhibitors, inotuzumab ozogamicin (InO) and blinatumomab are dismal. We treated two cases of Ph+ALL resistant to these drugs that achieved long-term survival after treatment with chimeric antigen receptor (CAR)-T cell therapy or a second allogeneic hematopoietic stem cell transplantation (HCT) with a sequential conditioning regimen. Case 1: A 15-year-old boy was diagnosed with Ph+ALL. Despite the second HCT after the treatment of ponatinib and blinatumomab, hematological relapse occurred. InO was ineffective and he was transferred to a CAR-T center. After the CAR-T cell therapy, negative measurable residual disease (MRD) was achieved and maintained for 38 months without maintenance therapy. Case 2: A 21-year-old man was diagnosed with Ph+ALL. Hematological relapse occurred after the first HCT. Despite of the treatment with InO, ponatinib, and blinatumomab, hematological remission was not achieved. The second HCT was performed using a sequential conditioning regimen with clofarabine. Negative MRD was subsequently achieved and maintained for 42 months without maintenance therapy. These strategies are suggestive and helpful to treat Ph+ALL resistant to multiple immunotherapies.

Resmetirom for treatment of MASH.

Resmetirom is an oral selective THR-ß agonist conditionally approved for the treatment of patients with noncirrhotic MASH with moderate to advanced fibrosis. Resmetirom restores mitochondrial and hepatic metabolic function; reduces atherogenic lipids; improves hepatic steatosis, inflammation, and fibrosis; and has no significant effect on THR-α. To view this Bench to Bedside, open or download the PDF.

Clinical outcomes of chronic myeloid leukaemia patients taking asciminib through a Managed Access Programme (MAP) in Australia.

Asciminib is a novel allosteric STAMP (specifically targets the ABL myristoyl pocket) inhibitor of the BCR::ABL1 oncogene. Real-world clinical outcomes of patients with tyrosine kinase inhibitor (TKI)-resistant/intolerant chronic myeloid leukaemia (CML) in Australia on the Managed Access Programme for asciminib showed higher molecular responses for those with intolerance versus resistance ± intolerance to their last TKI. There remains a clinical need to improve outcomes in patients with CML who have resistance to multiple TKIs, especially in the ponatinib-pretreated cohort.

Ponatinib vs Imatinib in Frontline Philadelphia Chromosome-Positive Acute Lymphoblastic Leukemia: A Randomized Clinical Trial.

Importance: In newly diagnosed Philadelphia chromosome-positive (Ph+) acute lymphoblastic leukemia (ALL), disease progression due to acquired resistance to first- or second-generation BCR::ABL1 tyrosine kinase inhibitors is common. Ponatinib inhibits BCR::ABL1 and all single-mutation variants, including T315I. Objective: To compare frontline ponatinib vs imatinib in adults with newly diagnosed Ph+ ALL. Design, Setting, and Participants: Global registrational, phase 3, open-label trial in adults aged 18 years or older with newly diagnosed Ph+ ALL. From January 2019 to May 2022, eligible patients at 77 sites were randomized 2:1 to ponatinib (30 mg/d) or imatinib (600 mg/d) with reduced-intensity chemotherapy, followed by single-agent ponatinib or imatinib after the cycle 20 phase of the trial. The last date of follow-up for this analysis was August 12, 2022. Intervention: Patients received ponatinib, 30 mg/d, or imatinib, 600 mg/d, with reduced-intensity chemotherapy, followed by single-agent ponatinib or imatinib after cycle 20. The ponatinib dose was reduced to 15 mg on achievement of minimal residual disease-(MRD) negative complete remission. Main Outcomes and Measures: The primary end point of this interim analysis was MRD-negative complete remission (≤0.01% BCR::ABL1 [MR4] centrally assessed by reverse transcriptase-quantitative polymerase chain reaction), with complete remission maintained for at least 4 weeks at the end of cycle 3. The key secondary end point was event-free survival. Results: Of 245 patients randomized (median age, 54 years; 133 [54.3%] female), 232 (ponatinib, n = 154; imatinib, n = 78) who had p190 or p210 dominant isoforms verified by the central laboratory were analyzed for the primary end point. The MRD-negative complete remission rate (primary end point) was significantly higher with ponatinib (34.4% [53/154]) vs imatinib (16.7% [13/78]) (risk difference, 0.18 [95% CI, 0.06-0.29]; P = .002). At the data cutoff, event-free survival had not met the prespecified number of events. Median event-free survival was not reached in the ponatinib group and was 29 months in the imatinib group. The most common adverse events were similar between treatment groups. Arterial occlusive events were infrequent and comparable between groups (ponatinib, 2.5%; imatinib, 1.2%). Conclusions and Relevance: Ponatinib demonstrated a superior rate of MRD-negative complete remission at the end of induction vs imatinib when combined with reduced-intensity chemotherapy in adults with newly diagnosed Ph+ ALL. The safety profile of ponatinib was comparable with imatinib. Trial Registration: ClinicalTrials.gov Identifier: NCT03589326.

Toxicities associated with tyrosine kinase inhibitor maintenance following allogeneic hematopoietic cell transplantation in Philadelphia chromosome-positive acute lymphoblastic leukemia.

Allogeneic hematopoietic cell transplantation (HCT) offers a potential cure in Philadelphia chromosome-positive (Ph+) acute lymphoblastic leukemia (ALL); nonetheless, relapses are common and the major cause of mortality. One strategy to prevent relapse is tyrosine kinase inhibitor (TKI) maintenance post-HCT, but published clinical experience is primarily with the first-generation TKI imatinib while data with newer generation TKIs are limited. We conducted a retrospective analysis of 185 Ph+ ALL patients who underwent HCT followed by TKI maintenance from 2003 to 2021 at City of Hope. Initially, 50 (27.0%) received imatinib, 118 (63.8%) received a second-generation TKI (2G-TKI), and 17 (9.2%) received ponatinib. A total of 77 patients (41.6%) required a dose reduction of their initial TKI due to toxicity. Sixty-six patients (35.7%) did not complete maintenance due to toxicity; 69 patients (37.3%) discontinued 1 TKI, and 11 (5.9%) discontinued 2 TKIs due to toxicity. Initial imatinib versus 2G-TKI versus ponatinib maintenance was discontinued in 19 (38.0%) versus 68 (57.6%) versus 3 (17.6%) patients due to toxicity (p = .003), respectively. Patients on ponatinib as their initial TKI had a longer duration of TKI maintenance versus 2G-TKI: 576.0 days (range, 72-921) versus 254.5 days (range, 3-2740; p = .02). The most common reasons for initial TKI discontinuation include gastrointestinal (GI) intolerance (15.1%), cytopenia (8.6%), and fluid retention (3.8%). The 5-year overall survival and progression-free survival for the total population were 78% and 71%, respectively. Our findings demonstrate the challenges of delivering post-HCT TKI maintenance in a large real-world cohort as toxicities leading to TKI interruptions, discontinuation, and dose reduction were common.

Ponatinib-review of historical development, current status, and future research.

Ponatinib is a third-generation BCR::ABL1 tyrosine kinase inhibitor (TKI) with high potency against Philadelphia chromosome (Ph)-positive leukemias, including T315I-mutated disease, which is resistant to first- and second-generation TKIs. Ponatinib was approved for T315I-mutated chronic myeloid leukemia (CML), CML resistant/intolerant to ≥2 prior TKIs, advanced phase CML and Ph-positive acute lymphoblastic leukemia (ALL) where no other TKIs are indicated, and T315I-mutated CML and Ph-positive ALL. The response-based dosing of ponatinib in chronic phase CML (CP-CML) improved treatment tolerance and reduced the risk of toxicities, including cardiovascular risks. Ponatinib-based therapy also resulted in significantly better outcomes in frontline Ph-positive ALL compared with prior TKIs and is becoming a new standard of care in this setting. As the clinical development of third-generation TKIs and their rational combinations progresses, we envision further transformative changes in the treatment of CML and Ph-positive ALL.

Real-world outcomes of ponatinib treatment in 724 patients with CML and Ph+ ALL: a post-marketing surveillance study with a special interest in arterial occlusive events in Japan.

BACKGROUND: In September 2016, ponatinib was approved in Japan for the treatment of patients with chronic myeloid leukemia with resistance/intolerance to prior tyrosine kinase inhibitors and patients with relapsed or refractory Philadelphia chromosome-positive acute lymphoblastic leukemia. METHODS: We conducted a post-marketing all-case surveillance to study the safety and efficacy of ponatinib in clinical practice, focusing on arterial occlusive events. RESULTS: Data from 724 patients were collected for 2 years from the initiation of ponatinib. The arterial occlusive events were reported in 6.49% (47/724) with an exposure-adjusted incidence rate of 6.8/100 person-years. The risks associated with arterial occlusive events were age and comorbidities including hypertension and diabetes. At 104 weeks, the cumulative major molecular response rate in patients with chronic-phase chronic myeloid leukemia was 67.2% and the complete cytogenetic response in patients with Philadelphia chromosome-positive acute lymphoblastic leukemia was 80.0%. Furthermore, the estimated 1-year overall survival rate was 98.5% for chronic-phase chronic myeloid leukemia and 68.6% for Philadelphia chromosome-positive acute lymphoblastic leukemia. CONCLUSIONS: This surveillance demonstrated that ponatinib has a favorable safety and efficacy profile in Japanese patients and also showed the necessity of closely monitoring arterial occlusive events in older adults and patients with predisposing factors for atherosclerosis.

Is intensive chemotherapy and allogeneic stem cell transplantation mandatory for curing Philadelphia chromosome-positive acute lymphoblastic leukemia in young patients in the era of multitarget agents?

INTRODUCTION: The treatment outcomes for Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ALL) have improved with various tyrosine kinase inhibitors (TKIs) and bispecific T-cell engagers. Although allogeneic stem cell transplantation (allo-SCT) is the standard treatment for young patients with Ph+ALL, its role remains debatable in the era of TKIs and blinatumomab. AREAS COVERED: There are some issues regarding Ph+ALL. First, do young patients require intensive chemotherapy (IC) in the era of multitarget agents? Second, which TKI is preferred for frontline therapy? Third, should allo-SCT be performed in patients achieving complete remission with ponatinib and IC? Fourth, can chemo-free treatment lead to a cure without allo-SCT? We searched relevant literature from the last 30 years on PubMed; reviewed the role of chemo-free therapies and combinations of ponatinib and IC; and assessed the necessity of allo-SCT in young patients with Ph+ALL. EXPERT OPINION: Allo-SCT may not be needed, even in young patients with Ph+ALL treated with ponatinib-based IC or combined ponatinib and blinatumomab as frontline therapy. When adopting a ponatinib-based chemo-minimized regimen for induction, allo-SCT is needed with posttransplant ponatinib maintenance. Continuous exposure to ponatinib at pre- or post-transplant is regarded as one of the most important factor for the success of treatment.

Endothelial function in patients with chronic myeloid leukemia treated with tyrosine kinase inhibitors is not related to cardiovascular risk assessed by the Systematic Coronary Risk Estimation 2 algorithm.

INTRODUCTION: Tyrosine kinase inhibitors (TKIs) revolutionized treatment of chronic myeloid leukemia (CML), but are endowed with negative effects on endothelial function. OBJECTIVES: We aimed to characterize endothelial function in patients with CML treated with various TKIs. PATIENTS AND METHODS: A total of 48 patients diagnosed with chronic­phase CML treated with TKIs, such as imatinib, bosutinib, nilotinib, ponatinib, and asciminib were included. Endothelial function was assessed in the brachial artery and microcirculation based on flow­mediated dilation (FMD), reactive hyperemia peripheral arterial tonometry (RH­PAT) and flow­mediated skin fluorescence (FMSF). RESULTS: Reactive hyperemia index, FMD, reactive hyperemia response (RHR), normoxia oscillatory index, and hyperemic response index did not differentiate between the group of patients with low / moderate risk in the Systematic Coronary Risk Estimation 2 (SCORE2), SCORE2­Older Persons (SCORE2­OP), and those with high / very high risk scores. Among the patients with low / intermediate risk based on the SCORE2 algorithm, some had lower (below the first quartile) values of the endothelial parameters, reflecting impaired endothelial function, as compared with the high / very high risk patient population. Lower values of the endothelial function parameters were associated with overall long­term treatment with TKIs or ponatinib. Importantly, endothelial function assessed by FMSF (RHR) negatively correlated with total duration of TKI treatment, also after adjustment for age. CONCLUSIONS: Endothelial function in CML patients treated with TKIs was not related to cardiovascular risk based on SCORE2/SCORE2­OP algorithms but correlated with CML­specific factors, including duration of TKI treatment. FMSF­based assessment of skin microcirculation was a sensitive method for detecting the vascular effects of TKIs.

EFFECTS OF LEVOSIMENDAN ON DIAPHRAGMATIC DYSFUNCTION IN PATIENTS WITH SEPSIS.

ABSTRACT: Objective: In this study, our aim was to examine the effects of levosimendan on diaphragmatic dysfunction in patients with sepsis, as well as assess its impact on respiratory muscle contractility and the outcome of weaning. Methods: This was a single-blind, randomized, controlled trial. Patients with diaphragmatic dysfunction and failure of spontaneous breathing trials (SBTs) were randomly and equally assigned to the experimental and control groups. The experimental group received levosimendan at a loading dose of 6 µg/kg for 10 min, followed by a continuous infusion at 0.2 µg/kg/min. The control group received an equivalent dose of a placebo. The preadministration and postadministration respiratory mechanics parameters of the patients were recorded. Evaluation of the effect of levosimendan on patients with sepsis-induced diaphragm dysfunction comprised arterial blood gas analysis as well as ultrasound measurements of diaphragm excursion (DE), diaphragm thickness (DT), diaphragm thickening fraction (TFdi), and diaphragm-rapid shallow breathing index (D-RSBI). Results: Forty-four patients were enrolled in the study. We found that postadministration of levosimendan, the patients' tidal volume (GCSMV) increased, whereas the D-RSBI decreased, and the partial pressure of carbon dioxide (PACO 2 ) decreased when compared to the preadministration levels. Additionally, following levosimendan administration, patients showed increased DE and pressure support (PS) when compared to before administration (1.14 ± 0.177 vs. 1.22 ± 0.170 cm and 0.248 ± 0.03 vs. 0.284 ± 0.06, respectively) and decreased D-RSBI (22.76 ± 6.14 vs. 20.06 ± 6.04, respectively), all of which were statistically significant ( P < 0.05). In contrast, in the control group of patients, there were no statistically significant differences in the postadministration levels of DE, TFdi, and D-RSBI as compared to the preadministration period ( P > 0.05). Furthermore, in terms of weaning outcomes, we did not find any statistically significant difference in the number of patients in the two groups who eventually underwent weaning ( P = 0.545). Conclusion: In this study, we found that levosimendan enhanced diaphragm contractile function. However, further investigations are required to explore its effect on weaning outcomes in patients undergoing mechanical ventilation.