[Progress and Application of Bayesian Approach in the Early Research and Development of New Anticancer Drugs].

Bayesian statistics is an approach for learning from evidences as it accumulates, combining prior distribution with current information on a quantity of interest, in which posterior distribution and inferences are being updated each time new data become available using Bayes' Theorem. Though frequentist approach has dominated medical studies, Bayesian approach has been more and more widely recognized by its flexibility and efficiency. Research and development (R&D) on anti-cancer new drugs have been so hot globally in recent years in spite of relatively high failure rate. It is the common demand of pharmaceutical enterprises and researchers to identify the optimal dose, regime and right population in the early-phase R&D stage more accurately and efficiently, especially when the following three major changes have been observed. The R&D on anticancer drugs have transformed from chemical drugs to biological products, from monotherapy to combination therapy, and the study design has also gradually changed from traditional way to innovative and adaptive mode. This also raises a number of subsequent challenges on decision-making of early R&D, such as inability to determine MTD, flexibility to deal with delayed toxicity, delayed response and dose-response changing relationships. It is because of the above emerging changes and challenges that the Bayesian approach is getting more and more attention from the industry. At least, Bayesian approach has more information for decision-making, which could potentially help enterprises achieve higher efficiency, shorter period and lower investment. This study also expounds the application of Bayesian statistics in the early R&D on anticancer new drugs, and compares and analyzes its idea and application scenarios with frequentist statistics, aiming to provide macroscopic and systematic reference for all related stakeholders.
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Efficacy of pramipexole on quality of life in patients with Parkinson's disease: a systematic review and meta-analysis.

BACKGROUND: Quality of life (QoL) in patients with Parkinson's disease (PD) is increasingly used as an efficacy outcome in clinical studies of PD to evaluate the impact of treatment from the patient's perspective. Studies demonstrating the treatment effect of pramipexole on QoL remain inconclusive. This study aims to evaluate the effect of pramipexole on QoL in patients with PD by conducting a systematic review and meta-analysis of existing clinical trials. METHODS: A systematic literature search of PubMed, Embase and the Cochrane Library was performed from inception to 30 April 2022 to identify randomised, placebo-controlled trials of patients with idiopathic PD receiving pramipexole, who reported a change from baseline in their QoL as measured by the 39-item Parkinson's Disease Questionnaire (PDQ-39). Risk of bias was independently assessed by two reviewers using the Cochrane Collaboration's tool for bias assessment. RESULTS: Of 80 eligible articles screened, six trials consisting of at least 2000 patients with early or advanced PD were included. From the synthesis of all six selected trials, a significant mean change from baseline in the PDQ-39 total score of -2.49 (95% CI, -3.43 to -1.54; p < 0.0001) was observed with pramipexole compared with placebo. A trend toward improvement in QoL was consistently observed among patients who received optimal doses of pramipexole (≥ 80% of the study population on 1.5 mg dosage), regardless of disease severity (advanced versus early) or baseline QoL levels. CONCLUSION: This meta-analysis provides evidence for the potential treatment benefit of pramipexole in improving QoL in patients with PD.

Parkinson's disease is a chronic, progressive nervous system disorder with no known cure. Patients may experience a number of symptoms including stiffness, slowness, and uncontrollable muscle movements, all of which impact their quality of life. Most clinical studies in Parkinson's disease measure the effect of treatment on improving symptoms, but other aspects such as quality of life are often overlooked. It is important to include quality of life measures in clinical studies of Parkinson's disease, such as the 39-item Parkinson's disease questionnaire (PDQ-39), to understand the impact of treatment from patients' perspectives. Pramipexole is a dopamine agonist that is well-tolerated and effective at treating Parkinson's disease symptoms. However, studies examining its effect on quality of life are inconclusive. This meta-analysis of existing clinical trials therefore aimed to evaluate the effect of pramipexole on quality of life in patients with Parkinson's disease. Six trials consisting of at least 2000 patients with early or advanced Parkinson's disease receiving treatment with pramipexole were included in this meta-analysis. Analysis of these six trials found a significant improvement in PDQ-39 total score with pramipexole compared with placebo. This meta-analysis provides new evidence for the potential treatment benefit of pramipexole in improving quality of life in patients with Parkinson's disease.

Phase I trial of the DLL3/CD3 bispecific T-cell engager BI 764532 in DLL3-positive small-cell lung cancer and neuroendocrine carcinomas.

Poorly differentiated neuroendocrine carcinomas such as small-cell lung cancer (SCLC) have poor survival and high relapse rates. DLL3 is found on these carcinomas and has become a target of increasing interest in recent years. The bispecific DLL3/CD3 T-cell engager BI 764532 has been shown to induce complete tumor regression in a human T cell-engrafted mouse model. Here, we describe the study design of a first-in-human, phase I, multicenter, open-label, non-randomized, dose-escalation study in patients with SCLC or other DLL3-positive neuroendocrine carcinomas. The study will determine the maximum tolerated dose and evaluate safety, tolerability, pharmacokinetics and preliminary efficacy of BI 764532 monotherapy.

DLL3 is a protein involved in development of the embryo during pregnancy. It has also been found on the surface of cells involved in the development of certain types of lung cancer and other tumors. The T-cell engager BI 764532 binds to DLL3 and cells of the immune system simultaneously, resulting in the death of tumor cells. Here we describe the rationale for, and design of, a clinical study of BI 764532 in patients with small-cell lung cancer and other tumors containing DLL3. The aim of the study is to find the highest acceptable dose of BI 764532 that can be tolerated by patients, and explore the safety and efficacy of BI 764532. Clinical Trial Registration: NCT04429087 (ClinicalTrials.gov).

Novel Structures of Type 1 Glyceraldehyde-3-phosphate Dehydrogenase from Escherichia coli Provide New Insights into the Mechanism of Generation of 1,3-Bisphosphoglyceric Acid.

Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) is a highly conserved enzyme involved in the ubiquitous process of glycolysis and presents a loop (residues 208-215 of Escherichia coli GAPDH) in two alternative conformations (I and II). It is uncertain what triggers this loop rearrangement, as well as which is the precise site from which phosphate attacks the thioacyl intermediate precursor of 1,3-bisphosphoglycerate (BPG). To clarify these uncertainties, we determined the crystal structures of complexes of wild-type GAPDH (WT) with NAD and phosphate or G3P, and of essentially inactive GAPDH mutants (C150S, H177A), trapping crystal structures for the thioacyl intermediate or for ternary complexes with NAD and either phosphate, BPG, or G3P. Analysis of these structures reported here lead us to propose that phosphate is located in the "new Pi site" attacks the thioester bond of the thioacyl intermediate to generate 1,3-bisphosphoglyceric acid (BPG). In the structure of the thioacyl intermediate, the mobile loop is in conformation II in subunits O, P, and R, while both conformations coexist in subunit Q. Moreover, only the Q subunit hosts bound NADH. In the R subunit, only the pyrophosphate part of NADH is well defined, and NADH is totally absent from the O and P subunits. Thus, the change in loop conformation appears to occur after NADH is produced, before NADH is released. In addition, two new D-glyceraldehyde-3-phosphate (G3P) binding forms are observed in WT.NAD.G3P and C150A+H177A.NAD.G3P. In summary, this paper improves our understanding of the GAPDH catalytic mechanism, particularly regarding BPG formation.

Expression, purification, crystallization and preliminary X-ray crystallographic analysis of fructose-1,6-bisphosphate aldolase from Escherichia coli.

Fructose-1,6-bisphosphate aldolase is one of the most important enzymes in the glycolytic pathway and catalyzes the reversible cleavage of fructose-1,6-bisphosphate to dihydroxyacetone phosphate and glyceraldehyde 3-phosphate. The full-length fbaB gene encoding fructose-1,6-bisphosphate aldolase class I (FBPA I) was cloned from Escherichia coli strain BL21. FBPA I was overexpressed in E. coli and purified. Biochemical analysis found that the optimum reaction temperature of FBPA I is 330.5 K and that the enzyme has a high temperature tolerance. Crystals of recombinant FBPA I were obtained by the sitting-drop vapour-diffusion technique in a condition consisting of 19 mg ml(-1) FBPA I in 0.1 M Tris pH 9.0, 10%(w/v) polyethylene glycol 8000 and diffracted to 2.0 Šresolution. The crystals belonged to the monoclinic space group C2, with unit-cell parameters a = 217.7, b = 114.9, c = 183.9 Å, ß = 124.6°. The asymmetric unit of these crystals may contain ten molecules, giving a Matthews coefficient of 2.48 Å(3) Da(-1) and a solvent content of 50.5%.

Crystal structure of the Tum1 protein from the yeast Saccharomyces cerevisiae.

Yeast tRNA-thiouridine modification protein 1 (Tum1) plays essential role in the sulfur transfer process of Urm1 system, which in turn is involved in many important cellular processes. In the rhodanese-like domain (RLD), conserved cysteine residue is proved to be the centre of active site of sulfurtransferases and crucial for the substrate recognition. In this report, we describe the crystal structure of Tum1 protein at 1.90 A resolution which, despite consisting of two RLDs, has only one conserved cysteine residue in the C-terminal RLD. An unaccounted electron density is found near the active site, which might point to the new cofactor in the sulfur transfer mechanism.

The dual role of ubiquitin-like protein Urm1 as a protein modifier and sulfur carrier.

The ubiquitin-related modifier Urm1 can be covalently conjugated to lysine residues of other proteins, such as yeast Ahp1 and human MOCS3, through a mechanism involving the E1-like protein Uba4 (MOCS3 in humans). Similar to ubiquitination, urmylation requires a thioester intermediate and forms isopeptide bonds between Urm1 and its substrates. In addition, the urmylation process can be significantly enhanced by oxidative stress. Recent findings have demonstrated that Urm1 also acts as a sulfur carrier in the thiolation of eukaryotic tRNA via a mechanism that requires the formation of a thiocarboxylated Urm1. This role is very similar to that of prokaryotic sulfur carriers such as MoaD and ThiS. Evidence strongly supports the hypothesis that Urm1 is the molecular fossil in the evolutionary link between prokaryotic sulfur carriers and eukaryotic ubiquitin-like proteins. In the present review, we discuss the dual role of Urm1 in protein and tRNA modification.

Crystallization and preliminary X-ray analysis of the yeast tRNA-thiouridine modification protein 1 (Tum1p).

Yeast tRNA-thiouridine modification protein 1 (Tum1p), a crucial component of the Urm1 system, is believed to play important roles in protein urmylation and tRNA-thiouridine modification. Previous studies have demonstrated that the conserved residue Cys259 in the C-terminal rhodanese-like domain of Tum1p is essential for these sulfur-transfer activities. Here, recombinant Tum1p protein has been cloned and overexpressed in Escherichia coli strain BL21 (DE3). After purification, crystals of Tum1p were obtained by the hanging-drop vapour-diffusion method and diffracted to 1.9 Šresolution. The preliminary X-ray data showed that the tetragonal Tum1p crystal belonged to space group I4(1), with unit-cell parameters a = b = 120.94, c = 48.35 Å. The asymmetric unit of the crystal was assumed to contain one protein molecule, giving a Matthews coefficient of 2.41 Å(3) Da(-1) and a solvent content of 49.0%.