Leining, a novel cytotoxic T-lymphocyte antigen-4 fusion protein

I was a bit surprised to read about Leining, a novel cytotoxic T-lymphocyte antigen-4 fusion protein in patients with rheumatoid arthritis.

W. Fan and colleagues just published: “A randomized, double-blind, and placebo-controlled multicenter clinical trial of a novel cytotoxic T-lymphocyte antigen-4 fusion protein, Leining, in Chinese active rheumatoid arthritis patients with an inadequate response to methotrexate.” Conclusions: “Leining demonstrated clinically meaningful efficacy compared with placebo in Chinese patients with active RA despite MTX therapy. Administration of Leining in combination with MTX for 24 weeks was well tolerated.” Link: http://www.ncbi.nlm.nih.gov/pubmed/24671501.

There had been an article in Acta Pharmacologica Sinica in 2009: “Pharmacokinetics of CTLA4Ig fusion protein in healthy volunteers and patients with rheumatoid arthritis” by Y. Ma and colleagues – a phase 1 study! Conclusions: “Intravenous infusion of CTLA4Ig was well tolerated in healthy volunteers and patients with rheumatoid arthritis. CTLA4Ig exhibited linear pharmacokinetics over the dose range of 1 to 20 mg/kg in healthy volunteers. The pharmacokinetics in RA patients appeared to be similar to that in healthy volunteers. No system accumulation appeared upon repeated infusions of 10 mg/kg every 4 weeks.” Link: http://www.nature.com/aps/journal/v30/n3/abs/aps200913a.html.

Leining looks like a biosimilar to abatacept (Orencia) to me. In abatacept the extracellular domain of CTLA-4 and the Fc region of the immunoglobulin IgG1 are fused together. As I couldn’t find anything on it, I’ve contacted W. Fan and colleagues to tell us, whether Leining is a biosimilar to abatacept or what else it is. 

23.08.2016:
I've never reiceived an answer to my email, but I have looked into other sources. Leining is tested for Shanghai CP Guojian Pharmaceutical, who already has introduced Yisaipu, a biosimilar to etanercept. Leining is indeed planned as a biosimilar to abatacept, but four years later it still isn't approved or manufactured for sale. Since 1st of Dec. 2011 Leining holds a preregistration for rheumatoid arthritis in China. No new developments since then, at least none that left traces on the internet. (Links: http://adisinsight.springer.com/drugs/800039891 http://www.cpgj-pharm.com/Products.asp?id=7)