Background: The prevalence of infections due to carbapenem-resistant Acinetobacter baumannii (CRAB) is on the rise worldwide. Polymyxins are considered as last-resort drugs for CRAB infections, but there is still controversy regarding the efficacy and safety of polymyxins based therapies in CRAB infections. The present systematic review was designed to compare the efficacy and safety of polymyxins based therapies versus non-polymyxins based therapies in CRAB infections. Methods: We performed a systematic literature search in PubMed, Embase, CINAHL, Cochrane Library, and clinicaltrials.gov to identify eligible studies reporting the clinical outcomes of patients with CRAB infections. The meta-analysis employed a random-effects model to estimate the odds ratio (OR) and standardized mean difference (SMD) with 95% confidence interval (CI). The primary outcome was 1-month mortality for any cause. We also examined clinical response, microbiological response, length of stay in hospital, and adverse events. Results: Eleven eligible studies were analyzed (1052 patients in total), including 2 randomized clinical trials. Serious risk of bias was found in 8 out of the 11 studies. There was no statistically significant difference between polymyxins based therapies and non-polymyxins based therapies in 1-month mortality for any cause (OR, 0.95; 95% CI, 0.59 to 1.53), microbiological response (OR, 3.83; 95% CI, 0.90 to 16.29) and length of stay in hospital (SMD, 0.24; 95% CI, − 0.08 to 0.56). The pooled OR of clinical response indicated a significant difference in favor of polymyxin based therapies (OR, 1.99; 95% CI, 1.31 to 3.03). The pooled OR of adverse events showed that non-polymyxins based therapies were associated with fewer adverse events (OR, 4.32; 95% CI, 1.39 to 13.48). Conclusion: The performance of polymyxins based therapies was better than non-polymyxin based therapies in clinical response rate and similar to non-polymyxin based therapies in terms of 1-month mortality and microbiological response in treating CRAB infections. Due to the limitations of our study, we cannot draw a firm conclusion on the optimal treatment of CRAB infections, but polymyxins would be a relatively effective treatment for CRAB infections. Adequate and well-designed large scale randomized controlled trials are required to clarify the relative efficacy of polymyxins based and non-polymyxins based therapies.

Obstructive hypertrophic cardiomyopathy (oHCM) is a subtype of HCM characterized by left ventricular outflow tract obstruction resulting from cardiac muscle hypertrophy and anatomic alterations in the mitral valve and apparatus. Mavacamten, a cardiac myosin inhibitor metabolized primarily by CYP2C19 in the liver, is the first and only targeted medication approved for the treatment of symptomatic New York Heart Association (NYHA) class II–III oHCM. Previous pharmacokinetic (PK) results of mavacamten in healthy Caucasian, Japanese, and Asian participants demonstrated that mavacamten exposure was affected by CYP2C19 metabolism status. This open‐label, parallel‐group, phase I trial aimed to determine the PK and safety of mavacamten in healthy Chinese participants with different CYP2C19 genotypes. The primary outcome was to define the PK of mavacamten in healthy Chinese participants; the secondary outcome was to examine safety and tolerability. After a single oral dose of 15 or 25 mg mavacamten in fasted healthy adult Chinese individuals, C_max was reached within a median T_max of 0.6–1.5 h, indicating rapid absorption. Inter‐individual variability was moderate, and individuals carrying non‐functional CYP2C19 alleles (*2/*2, *3/*3, or *2/*3) exhibited longer half‐life and increased total exposure. After stratification of CYP2C19 genotypes, total mavacamten exposures were similar among different ethnic groups when compared with prior PK studies. No significant adverse events were observed in this study. Single oral administration of mavacamten at 15 mg was well tolerated across all CYP2C19 genotypes, and 25 mg dose was well tolerated in healthy participants with CYP2C19 genotypes UM/RM/NM. The PK profile of mavacamten in the healthy Chinese population was consistent with that in other healthy populations.

Infigratinib, an FGFR1‐3 selective oral tyrosine kinase inhibitor, has shown clinical activity in cancers with FGFR alterations. The pharmacokinetics (PK) of infigratinib and its major metabolites have been characterized in global populations. This study examined the PK profile of infigratinib and its metabolites in Chinese patients. In this phase II, open‐label, single‐arm study in China, patients with advanced gastric cancer (GC) or gastroesophageal junction adenocarcinoma (GEJ) harboring FGFR2 gene amplification received 125 mg infigratinib orally once daily in a “3 weeks on, 1 week off” schedule for 28‐day cycles. Plasma PK parameters were calculated with a non‐compartmental model. Data were available from 21 patients (19 GC and two GEJ). After a single dose, peak infigratinib plasma concentration was reached at a median time of 3.1 h, with geometric mean C_max of 85.9 ng/mL and AUC_0‐t of 637 h*ng/mL. After 21‐day dosing, geometric mean infigratinib C_max,ss of 204 ng/mL was reached at a median of 4.0 h; geometric mean AUC_0‐24,ss was 3060 h*ng/mL. The geometric mean R_ac,_Cmax (%CV) and R_ac,_AUC0‐24 (%CV) of infigratinib was 2.5 (113.8) and 5.1 (138.2), respectively. A steady state of infigratinib was reached after continuous dosing for 15 days. The metabolites accounting for >10% of infigratinib were BHS697 and CQM157. The PK profiles of infigratinib and its metabolites in Chinese patients with GC or GEJ were largely consistent with known PK profiles of infigratinib from global populations.

Mavacamten is a cardiac myosin inhibitor for adults with obstructive hypertrophic cardiomyopathy (HCM). Dose optimization is performed 4 weeks after starting mavacamten, guided by periodic echo measurements of Valsalva left ventricular outflow tract gradient (VLVOTg) and left ventricular ejection fraction (LVEF). Previously, a population pharmacokinetic (PPK) model was developed and exposure‐response (E‐R) of VLVOTg (efficacy) and LVEF (safety) was used to identify the mavacamten titration regimen with the optimal benefit/risk ratio, now included in the US prescribing information. Mavacamten is metabolized primarily by cytochrome P450 2C19 (CYP2C19) (74%), a highly polymorphic enzyme. China has a higher prevalence of poor CYP2C19 metabolizer phenotype compared with the global population; therefore, a previous model was adapted to include Chinese patients with obstructive HCM to identify the optimal dosing regimen for this population. Data from a phase I (healthy Chinese volunteers) and a phase III (EXPLORER‐CN, NCT05174416; Chinese patients with obstructive HCM) trial of mavacamten were added to the previous PPK and E‐R models, and the observed VLVOTg and LVEF from EXPLORER‐CN were successfully simulated. Next, five echocardiography‐guided titration regimens (plus the EXPLORER‐CN regimen) using representative or equal CYP2C19 phenotypes were simulated. The final simulated regimen recommended with an optimal benefit/risk profile across CYP2C19 phenotypes included: down‐titration at Week 4 (if VLVOTg < 20 mmHg), restart at Week 12, and up‐titration at Week 12 (for VLVOTg ≥ 30 mmHg and LVEF ≥ 55%), and every 12 weeks thereafter. This supports the previously recommended regimen for Chinese patients with obstructive HCM, now approved by the National Medicinal Products Administration.