Rheumatoid arthritis (RA), spondyloarthritis (SPA) and psoriatic arthritis (PsA) are the most frequent and severe chronic inflammatory rheumatic diseases. The treatment of these diseases was strikingly improved within two decades by biological disease-modifying anti rheumatic drugs (bDMARDs). In 2018, numerous efficacious bDMARDs are available with different modes of action such as TNF inhibition, T cell co-stimulation blockade, IL-6 receptor inhibition, B cell depletion, in RA, as well as bDMARDs targeting IL-17, IL-23, IL-12, in PsA and SPA. The cost of these drugs is very high and was recently reduced by the use of "biosimilar drugs" (available today for some of these drugs). Although these bDMARDs are highly effective, with a satisfactory tolerance, the ideal target of therapy with achievement of clinical remission or low disease activity is not observed in a significant number of patients. Very active fundamental and translational research is still mandatory for the development of new bDMARDs or targeted synthetic DMARDs (tsDMARDs) with new targets of therapy, better efficacy and tolerance, and reduced costs.