In order to achieve therapeutic effect, most protein drugs often need multiple and high-dose injections, which increases the treatment burden and reduces the compliance of patients. Therefore, a variety of long-acting methods of protein have been developed at present, including mutation modification of protein to improve protein stability and avoid being recognized and decomposed by protease. However, after mutation, it is easy to produce immunogenicity and reduce the function of drugs in vivo; The other is PEG coupling. By increasing the hydration radius of the protein, it can avoid being quickly cleared by the kidney, and at the same time, it can mask some protease sites and delay the degradation rate. However, high molecular weight PEG is easy to cause loss of protein activity, and there is a risk of kidney accumulation leading to glomerular hollowing. In addition, there is the strategy of coupling Fc to develop fusion protein. However, this method requires the production and expression system of eukaryotic mammalian cells, which has great limitations in production costs and application scenarios.

Loqi Biological has developed a long-acting platform of albumin nanoantibody, and specifically developed camel antibody that combines with human serum albumin. This series of antibodies can extend the half-life by combining with human serum albumin, and because of its small molecular weight, it can avoid the adverse effects of HSA, Fc and other fusion proteins on activity, process and efficacy. Moreover, the humanized HSA-specific single-domain antibody and its antibody combination can also be produced in the Pichia pastoris expression system, which greatly reduces the cost of medication, and has great potential as a long-term and high-dose treatment drug for chronic diseases. This platform has great clinical value.