The PsO market has typically been dominated by injectable biologics, manufactured by one of several large pharmaceutical companies. However, although there are several biologics in the late-stage PsO pipeline, key opinion leaders (KOLs) interviewed by GlobalData largely agree that this segment of the market is fairly saturated, given the number of different efficacious biologics already available. Due to the crowded nature of the market, standards for pivotal clinical trials have only become more rigorous in the last five years.

While previously the PASI 75 was widely used as a standard PsO trial endpoint, KOLs noted that this is no longer sufficient to be competitive in the current market. Many drugs in recent years have been able to achieve the PASI 90 or even full skin clearance, as measured by the PASI 100. Agents still using the PASI 75 are now assumed to be in development for mild-to-moderate PsO patients. Additionally, many pivotal and post-marketing trials are also incorporating the IGA or sPGA as co-primary endpoints in addition to the PASI system. KOLs noted that the IGA and sPGA are more widely understood by non-researching clinicians, which speaks to the competitive nature of the field and the need to stake a claim in both the minds and prescription pads of community prescribers.

In addition to more rigorous clinical endpoints becoming the norm, the monitoring interval for primary endpoints is also extended compared to previous years. While initial primary endpoints in PsO trials have typically been assessed at 12 weeks of therapy, the primary endpoints of several trials have been stretched out to 52 weeks and beyond. Physicians interviewed by GlobalData expressed a need to understand the long-term efficacy and safety of therapies, since they often only see patients once a year or even less frequently. Drug manufacturers are using head-to-head comparator trials both before and after drug approval to establish their products’ clinical and commercial positioning within the treatment landscape.

The main factors that drive the competition within the PsO market are safety and efficacy. As a result, there are currently a number of head-to-head trials being conducted to prove that newer biologics are more efficacious compared to gold-standard treatments. TNF-inhibitor Humira (adalimumab) has been a commonly used comparator for biologic trials, though others have also utilised IL-12/23 inhibitor Stelara (ustekinumab) and IL-17 inhibitor Cosentyx (secukinumab). KOLs expressed an interest in these trials being adequately large to compare the two active agents with statistical power, utilizing several hundred patients at a minimum. Notably, BMS’ deucravacitinib is currently being investigated in comparison to Otezla. KOLs interviewed by GlobalData praised this trial design for its clinical utility in establishing where deucravacitinib might fit into their current treatment paradigm.

Long-term clinical data from both pre and post-marketing studies are increasingly important tools in guiding physician prescribing patterns. The bar for clinical endpoints continues to rise, with many studies utilising more robust endpoints than those seen five years ago. Additionally, head-to-head trials comparing pipeline agents against well-established drugs are becoming necessary for drugs to stake a claim in the market. The market dynamics are complex and drug manufacturers have no choice but to continue setting and exceeding increasingly high clinical development standards in order to gain a foothold in this mature field.