Sorrento Therapeutics Inc. has completed its acquisition of biotech company Concortis Biosystems Corp., Sorrento announced.

The transaction, which involves two San Diego-based companies, is valued at about $11.3 million.

Sorrento (Nasdaq: SRNE) said the acquisition will enable it to develop antibody-drug conjugates — a new class of potent biopharmaceutical drugs for targeted cancer treatment.

2013 has been a busy year for Sorrento Therapeutics, a $173.9 million market cap company. It acquired companies including New York-based Sherrington Pharmaceuticals Inc. and Fountain Valley-based Igdrasol Inc. for undisclosed sums. Sorrento also transitioned to the Nasdaq and recently closed a $35 million stock offering.