The market for psoriatic arthritis (PsA) therapies will grow nearly 66%, increasing to $3.7 billion in 2023, due to the continued uptake of premium-price biologics and novel therapies expected to launch during the 2013 to 2023 forecast period, according to Burlington, Mass.-based Decision Resources Group.

Less-expensive biosimilar versions of several biologics will launch beginning in 2015 and will erode biologics’ sales through 2023, with the largest impact on the TNF-alpha inhibitor class.

Interviewed thought leaders report that conventional DMARDs and TNF-alpha inhibitors are the clinical mainstays for mild and moderate-to-severe PsA, respectively, and will face only moderate loss of patient shares to recently launched and incoming novel therapies.

Bingnan Kang, Ph.D., director of Decision Resources Group, said, “The addition of the TNF-alpha inhibitors to the PsA treatment algorithm represented a significant step forward in the management of this heterogeneous disease. Despite advances in the diagnosis and treatment of PsA, significant opportunity remains for developers of additional disease-modifying agents and agents with a high degree of efficacy against multiple disease manifestations.”

“Biosimilar versions of etanercept, adalimumab and infliximab are expected to launch in most or all of the major markets during the forecast period and to account for approximately 36% of TNF-alpha inhibitor sales for PsA in 2023,” said Kang. “Our primary research indicates that most rheumatologists will feel comfortable prescribing biosimilars for PsA, based on biosimilars’ clinical trial data in RA, thereby reducing biosimilars’ barrier to entry in this market.”