A Variable Step Crow Search Algorithm and Its Application in Function Problems

Optimization algorithms are popular to solve different problems in many fields, and are inspired by natural principles, animal living habits, plant pollinations, chemistry principles, and physic principles. Optimization algorithm performances will directly impact on solving accuracy. The Crow Search Algorithm (CSA) is a simple and efficient algorithm inspired by the natural behaviors of crows. However, the flight length of CSA is a fixed value, which makes the algorithm fall into the local optimum, severely limiting the algorithm solving ability. To solve this problem, this paper proposes a Variable Step Crow Search Algorithm (VSCSA). The proposed algorithm uses the cosine function to enhance CSA searching abilities, which greatly improves both the solution quality of the population and the convergence speed. In the update phase, the VSCSA increases population diversities and enhances the global searching ability of the basic CSA. The experiment used 14 test functions,2017 CEC functions, and engineering application problems to compare VSCSA with different algorithms. The experiment results showed that VSCSA performs better in fitness values, iteration curves, box plots, searching paths, and the Wilcoxon test results, which indicates that VSCSA has strong competitiveness and sufficient superiority. The VSCSA has outstanding performances in various test functions and the searching accuracy has been greatly improved

A new dosing regimen of ropeginterferon alfa-2b is highly effective and tolerable: findings from a phase 2 study in Chinese patients with polycythemia vera

Abstract Ropeginterferon alfa-2b represents a new-generation pegylated interferon-based therapy and is administered every 2–4 weeks. It is approved for polycythemia vera (PV) treatment in the United States and Europe with a starting dose of 100 µg (50 µg for patients receiving hydoxyurea) and intra-patient dose titrations up to 500 µg at 50 µg increments, which took approximately 20 or more weeks to reach a plateau dose level. This study aimed to assess ropeginterferon alfa-2b at an alternative dosing regimen with a higher starting dose and quicker intra-patient dose titrations, i.e., the 250–350–500 μg schema, in 49 Chinese patients with PV with resistance or intolerance to hydroxyurea. The primary endpoint of the complete hematologic response rate at treatment weak 24 was 61.2%, which was notably higher than 43.1% at 12 months with the approved dosing schema. The JAK2 V617F allele burden decreased from baseline to week 24 (17.8% ± 18.0%), with one patient achieving a complete molecular response. Ropeginterferon alfa-2b was well-tolerated and most adverse events (AEs) were mild or moderate. Common AEs included alanine aminotransferase and aspartate aminotransferase increases mostly at grade 1 or 2 levels. Patients did not present with jaundice or significant bilirubin level increase. No grade 4 or 5 AEs occurred. Seven patients (14.3%) experienced reversible, drug-related grade 3 AEs. No AEs led to treatment discontinuation. Ropeginterferon alfa-2b at the 250–350–500 μg regimen is highly effective and well-tolerated and can help patients achieve greater and rapid complete hematologic and molecular responses. Clinical Trial Registration: This trial is registered at ClinicalTrials.gov (Identifier: NCT05485948) and in China (China National Medical Products Administration Registration Number: CTR20211664)