Treatment outcomes for patients with moderate to severe plaque psoriasis can vary based on multiple factors, including patient demographics and disease characteristics, and these may not always be reflected in the results demonstrated in clinical trials. As real-world evidence continues to grow in the treatment of patients with plaque psoriasis, so will the knowledge base for the personalization of treatment strategies.

One important factor when considering efficacy results from clinical trial data vs real-world data is patient adherence. In clinical trials, patients tend to be more adherent to their prescribed therapy than they are in the real-world setting. That difference is partially driven by how frequently patients participating in trials return to the study site. Those patients might be seen 6 times in 12 weeks, while in clinical practice, patients can often go 2 to 3 months between visits. Therefore, clinical study findings may overestimate the efficacy of a treatment simply because our patients in the real-world setting might not use their prescribed medications as consistently as those participating in clinical trials.

Another important difference between clinical trial and real-world data is that, in a clinical trial setting, patients typically receive a single drug in a controlled manner to best evaluate the safety and efficacy of that single therapy. In real life, our patients with plaque psoriasis may use multiple medications; for example, a biologic therapy may be paired with a topical medication. It is possible that, by giving patients multiple medications, we are complicating their treatment and potentially reducing their medication adherence, which, in turn, can negatively impact therapeutic outcomes.

Real-world data are very helpful for gathering additional safety and tolerability information. Clinical studies are typically designed and powered to identify statistically significant differences in efficacy between the study drug and placebo, but they are often not large enough to identify the rates of rare adverse events. Database registries and other real-world studies can include very large numbers of patients, follow them over time, and observe the rates of safety events. Of course, such studies usually do not include placebo groups for comparison, which must be considered when evaluating the findings.

Clinical trials—especially those that are intended for US Food and Drug Administration approval—are often conducted over a shorter time frame, resulting in a limited window when looking at primary outcome data results. These trials do not always represent what we see and experience with our patients in real-world practice. It is also prudent to consider how we evaluate and interpret data generated from clinical trials vs the real world. This is because the validated research tools and metrics used to assess therapeutic efficacy for patients in a trial, while important, will not always directly translate to the same patient success in our clinical practice.

Efficacy results may be greater in clinical trials vs the real world because of the amount of patient oversight and its implications for adherence, as Dr Feldman mentioned. Additionally, there may be patients whose progress on treatment might not be considered a success by clinical trial standards, but in the eyes of the physicians or the patients themselves, the improvements could be considered significant. Clinical trial data can, therefore, be somewhat limited from a pragmatic perspective in that they do not always reflect the messy day-to-day realities of practice.

In terms of real-world data, retrospective chart review studies can be especially useful for giving us an idea of how various agents behave when combined with other therapies because we typically prescribe multiple therapies for patients with plaque psoriasis at once. From a safety perspective, disease state registries are very helpful in showing whether new safety signals emerge beyond the time frame of the original clinical trial period.

In general, real-world data, including results gathered from registry databases, will typically report lower efficacy results for therapies compared with clinical trials. This occurs for all the reasons my colleagues have discussed, with adherence being an important factor. Data sets can provide valuable information if they include sufficiently broad groups of patients. Evaluating the real-world data for a single drug experience in 800 patients in a registry is not ideal. We cannot adequately learn about safety and efficacy without comparators. When a registry or data set is disease-specific and allows patients to be on any number of treatments, it gives us broader data to evaluate. This provides valid comparators that can help us make decisions about therapeutic safety and efficacy in the real world.

The Psoriasis Longitudinal Assessment and Registry is a good example of a valuable registry for patients with psoriasis. Patients in the registry were followed for years and were treated with many different therapies, providing us with valuable data on the disease state and patient outcomes. The CorEvitas Psoriasis Registry (formerly known as the Corrona Psoriasis Registry) is another disease-specific registry that has followed thousands of patients with psoriasis being treated with many different drugs over an extended period of time, and it has provided valuable real-world information regarding the disease state and its treatment.