Circio Holding and Avenue Biosciences entered a research collaboration aimed at improving long-term secretion of proteins produced using Circio’s circVec platform. The partnership focuses on engineering signal peptides to boost how efficiently therapeutic proteins are exported from cells, with an initial screening workload handled by Avenue and follow-on in vitro and in vivo testing performed by Circio. The deal targets a common gene-therapy bottleneck: insufficient protein expression that can force higher doses and complicate manufacturing. Both companies framed the secretory pathway as an underutilized engineering lever for expanding payload options beyond classical monogenic indications. The collaboration will evaluate whether combining circVec’s durable circular RNA expression with Avenue’s protein-secretion optimization can increase protein output per dose across therapeutic protein classes, including antibodies, according to the companies’ statements.