Safety and efficacy of trastuzumab biosimilar plus irinotecan or gemcitabine in patients with previously treated HER2 (ERBB2)-positive non-breast/non-gastric solid tumors: a phase II basket trial with circulating tumor DNA analysis.

BACKGROUND: Human epidermal growth factor receptor 2 (HER2) (ERBB2)-directed agents are standard treatments for patients with HER2-positive breast and gastric cancer. Herein, we report the results of an open-label, single-center, phase II basket trial to investigate the efficacy and safety of trastuzumab biosimilar (Samfenet®) plus treatment of physician's choice for patients with previously treated HER2-positive advanced solid tumors, along with biomarker analysis employing circulating tumor DNA (ctDNA) sequencing. METHODS: Patients with HER2-positive unresectable or metastatic non-breast, non-gastric solid tumors who failed at least one prior treatment were included in this study conducted at Asan Medical Center, Seoul, Korea. Patients received trastuzumab combined with irinotecan or gemcitabine at the treating physicians' discretion. The primary endpoint was the objective response rate as per RECIST version 1.1. Plasma samples were collected at baseline and at the time of disease progression for ctDNA analysis. RESULTS: Twenty-three patients were screened from 31 December 2019 to 17 September 2021, and 20 were enrolled in this study. Their median age was 64 years (30-84 years), and 13 patients (65.0%) were male. The most common primary tumor was hepatobiliary cancer (seven patients, 35.0%), followed by colorectal cancer (six patients, 30.0%). Among 18 patients with an available response evaluation, the objective response rate was 11.1% (95% confidence interval 3.1% to 32.8%). ERBB2 amplification was detected from ctDNA analysis of baseline plasma samples in 85% of patients (n = 17), and the ERBB2 copy number from ctDNA analysis showed a significant correlation with the results from tissue sequencing. Among 16 patients with post-progression ctDNA analysis, 7 (43.8%) developed new alterations. None of the patients discontinued the study due to adverse events. CONCLUSIONS: Trastuzumab plus irinotecan or gemcitabine was safe and feasible for patients with previously treated HER2-positive advanced solid tumors with modest efficacy outcomes, and ctDNA analysis was useful for detecting HER2 amplification.

Estimating the Basal metabolic rate from fat free mass in individuals with motor complete spinal cord injury.

STUDY DESIGN: Cross-sectional study. OBJECTIVES: This study aimed to validate the existing basal metabolic rate (BMR) predictive equations that include fat free mass (FFM) as an independent variable and, based on the FFM assessment, to develop a new SCI population-specific equation. SETTING: Outpatient clinic in a general hospital. METHODS: Our study group was formed of 50 individuals with chronic motor complete SCI: 27 patients with tetraplegia and 23 with paraplegia. Both BMR and FFM values were measured by indirect calorimetry (IC) and the whole-body dual energy X-ray absorptiometry, respectively. The BMR values measured by IC were compared with the values estimated from the Cunningham equation. Multiple linear regression analysis was performed to develop a new FFM-based, BMR predictive equation. RESULTS: The mean value of BMR measured by IC was 1274.8 (s.d.=235.2) kcal day-1. The intra-class correlation coefficient (ICC) between values measured by IC and estimated from the Cunningham equation was 0.845 and the limits of agreement ranged from -30.6 to 241.3 kcal. SCI population specific BMR predictive equation was developed; BMR (kcal day-1)=24.5 × FFM (kg)+244.4. The newly developed equation showed ICC of 0.866 with the limits of agreement from -229.0 to 233.1 kcal day-1. CONCLUSIONS: A considerable bias from the BMR values measured by IC was still observed, which warrants clinical consideration when applying FFM-based BMR prediction equations to individuals with SCI.

Severe spasticity in lower extremities is associated with reduced adiposity and lower fasting plasma glucose level in persons with spinal cord injury.

STUDY DESIGN: Cross-sectional study. OBJECTIVES: To investigate the effects of severe lower extremity spasticity on anthropometric dimensions, body composition and metabolic profiles in persons with chronic motor complete spinal cord injury (SCI). SETTING: Outpatient clinic. METHODS: Fifty-five of the 61 participants were divided into two groups (no or mild spasticity group, 28; severe spasticity group, 27) based on the assessment of the extensor muscle spasticity according to the modified Ashworth scale. Anthropometric dimensions (waist circumference (WC), waist-to-height ratio (WtHR)), body composition (fat mass (FM), body fat percentage (BFP), fat-free mass (FFM), fat-free mass percentage (FFMP), bone mineral density (BMD)) and metabolic profiles (leptin, total cholesterol, low-density lipoprotein (LDL), high-density lipoprotein (HDL), triglyceride (TG), fasting plasma glucose (FPG) and glycosylated hemoglobin (HbA1c)) were compared between the two groups with different degree of spasticity. RESULTS: Spasticity of the extensor muscle group negatively correlated with BFP (r=-0.458, P<0.001). Patients with severe spasticity showed a lower WC and WtHR than those in the no or mild spasticity group (P=0.038, P=0.006, respectively). The FM, BFP, leptin and FPG of the severe spasticity group were significantly lower than those of the patients in the no or mild spasticity group (P=0.003, P<0.001, P<0.001 and P=0.037, respectively). However, no differences in BMD, total cholesterol, LDL, HDL, TG and HbA1c were observed between the groups. CONCLUSIONS: The results of this study suggest that severe spasticity in lower extremities is associated with reduced adiposity and lower FPG levels in persons with chronic motor complete SCI.

In vitro selection of RNA against kanamycin B.

Aminoglycosides are well-known antibiotics that function by interacting with ribosomal RNA in bacteria. In order to understand the molecular details between RNA and the drug, RNA aptamer was selected against kanamycin B. After 12 cycles of selection, RNA was cloned and sequenced. Among 9 clones, sequences of three clones were identical, suggesting the selected RNA was enriched. Among the cloned RNA molecules, the triplicated RNA was the maximum binding RNA. It showed a 180 nM affinity (KD) to the cognate aminoglycoside, as measured by a surface plasmon resonance, and a competition assay using a fluorescence anisotropy technique. The affinity of the maximum binding RNA to a similar aminoglycoside, tobramycin, was much stronger than 12 nM of KD. The binding site of the aminoglycoside in the maximum binding RNA was a stem loop located at the end of the 5' region. A stem loop structural motif, found in this study, was similar to those previously reported, even though the sequences of the RNA were totally different from the known sequences of the aminoglycoside binding site of other aptamers. The present study suggests that the aminoglycoside-binding region in RNA does not have a sequence specificity, but has a shape-specific bulged stem loop, even though it has a nanomolar affinity.