Developers are steadily increasing the number of monoclonal antibody (mAb) products for which they are initiating clinical studies, extending a trend that began in the 1990s, according to a new report.

The number of novel mAbs entering clinical study worldwide annually rose from 19 in 1997 to 53 in 2010, peaking at 54 in 2008, thus continuing a trend dating back to the mid-1980s, when about a dozen mAb candidates entered clinical study each year, reports the Tufts Center for the Study of Drug Development (CSDD).

From 1997 through 2010, clinical and Food and Drug Administration (FDA) approval phases for mAb therapeutics averaged 7.2 years and 1.0 years, respectively, it notes.

Total development and approval times for mAbs compare favourably with small-molecule drugs, which require an average of 7.5 years in total to follow the same path, as well as with biotechnology products, which require an average of eight years, says the study.

"Advances in antibody engineering and design, improvement in cell lines and manufacturing, and better understanding of targets and mechanisms of action are some of the key reasons why more mAbs are entering clinical study," says study author Janice Reichert, research assistant professor and senior research fellow at Tufts CSDD.

Today, about 314 mAb products are in clinical study worldwide, according to the study, which is reported in the November/December Tufts CSDD Impact Report.

The research also finds that the cumulative success rate - mAbs that have completed clinical trials and received FDA approval - is 17% for all humanised mAb candidates, with a lower rate (13%) for anticancer candidates and a higher one (26%) for immunological candidates, and that FDA approvals have recently dropped slightly, from 16 during 1997-2004 to 13 in 2005-11.

Of the mAbs now in clinical study, 51% are focused on anticancer therapies and 27% on immunological treatments, the study reports.