Recruiting, designing, and running psoriasis clinical trials is far more complex than it looks on paper. Between competition for patients already on biologics, differing endpoint expectations across regions, and the operational strain on sites, sponsors face a trial landscape filled with hurdles. The good news is that these challenges tend to follow predictable patterns. By understanding where psoriasis trials most often struggle in recruitment, endpoints, site readiness, regulatory alignment, and resourcing, sponsors can take practical steps to avoid costly setbacks.

By identifying these common hurdles early, sponsors can plan more effectively, streamline their processes, and prevent delays that often affect many psoriasis studies. Let’s take a closer look at the five most common challenges and how to solve them.

Patient Recruitment Shortfalls

Industry-wide, over 80% of clinical trials fail to meet their initial enrollment targets and timelines. Psoriasis studies face even greater difficulties, such as a smaller pool of moderate-to-severe patients, many of whom are already using biologics, along with strict eligibility criteria, which make recruitment even more challenging.

These barriers are real, but they are also solvable when sponsors adjust recruitment strategies to the realities of today’s patient landscape.

How to Improve Recruitment:

• Expand outreach: Use digital campaigns and social media to reach beyond a single site’s patients. Some studies have recruited hundreds within weeks using online methods.
• Engage networks: Partner with dermatology clinics and patient advocacy groups to spread awareness and build trust.
• Streamline screening: Use online pre-screeners and provide clear patient-friendly materials to prevent dropouts during early visits.
• Broaden eligibility thoughtfully: Remove non-essential exclusion criteria to open the trial to more patients without compromising safety.

At TFS, we have seen how proactive planning and close site engagement can turn recruitment hurdles into success stories. In one recent study, our team helped a sponsor overcome both enrollment and safety challenges to deliver on time, despite significant barriers. Read the case study here.

Endpoint Selection (PASI vs. PGA)

Endpoints define how success is measured, and psoriasis studies face the challenge of choosing between PASI and PGA. The Psoriasis Area and Severity Index (PASI) provides detailed scoring but requires training for consistent use. The Physician’s Global Assessment (PGA) is more straightforward and quicker but less detailed. Regulators add another layer of complexity: the FDA tends to favor PGA 0 or 1 (clear or almost clear), while the EMA often prefers PASI outcomes.

Different scoring tools can complicate both trial design and regulatory alignment, but sponsors have options to simplify endpoints and strengthen outcomes.

How to Choose the Right Endpoints:

• Use co-primary endpoints: Recent pivotal Phase III used both PASI and PGA 0/1 as co-primary endpoints. This approach aligns with regulatory expectations and offers a fuller picture of efficacy.
• Aim higher: Include PASI-90 or PASI-100 if your therapy can achieve near-clearance to stay competitive.
• Add patient-reported outcomes: Measures like DLQI or itch severity capture the patient perspective and strengthen regulatory submissions.

Site Readiness and Consistency

Even strong protocols can falter if sites are not fully prepared. Psoriasis assessments need judgment, and without proper training, PASI or PGA scores can differ significantly between investigators. Some sites may also lack the infrastructure or staff needed to handle complex dermatology studies.

Operational consistency is difficult across multiple sites, yet it can be achieved when sponsors focus on preparation and support from the start.

How to Strengthen Site Readiness:

• Select experienced sites: Prioritize investigators who have dermatology trial experience and established patient access.
• Standardize investigator training: Structured training and periodic refresher sessions validate each investigator’s ability to apply PASI and PGA scoring consistently, including across different skin tones.
• Confirm infrastructure early: Ensure sites have photography equipment, lab access, and dedicated staff before first patient in. Provide checklists and ongoing support throughout the study.

Regulatory Hurdles

Psoriasis is a competitive market, and regulators expect new therapies to demonstrate both high efficacy and long-term safety. Differences between FDA and EMA preferences can add complexity to global trials by increasing the assessment burden, even if the overall design remains straightforward. Chronic-use therapies require extended monitoring for delayed adverse effects, thus extending trial timelines. For biotech sponsors, staying compliant and maintaining documentation across multiple regions can be particularly challenging.

Different requirements among agencies may seem overwhelming, but early planning and alignment help keep trials on track globally.

How to Navigate Regulatory Hurdles:

• Engage early: Obtain feedback from regulators before finalizing protocol design to confirm acceptable endpoints and safety measures.
• Design for multiple regions: Include both PASI and PGA endpoints and align your statistical analysis plan accordingly.
• Maintain compliance throughout: Maintain thorough documentation, enforce GCP standards, and conduct regular quality checks to remain inspection-ready.

Resource Limitations

Psoriasis trials are costly and resource-demanding. Producing biologic supplies, overseeing multiple sites, ensuring data quality, and reimbursing patients all contribute to expenses. Biotech sponsors often operate with limited staff covering numerous roles, which increases the risk of delays if issues aren’t identified quickly and promptly resolved.

Budget and staffing pressures are unavoidable in complex studies, but implementing the right strategies can help sponsors extend resources without compromising quality.

How to Optimize Resources:

• Focus on critical-path activities: Prioritize recruitment, site training, and endpoint reliability.
• Leverage experienced partners: An established dermatology CRO can provide site networks, operational support, and regulatory expertise without the overhead of building them internally.
• Adopt efficient methods: Adaptive trial designs, remote monitoring, and ePRO systems help manage endpoints and lower costs while keeping quality high.

Bottom Line

Psoriasis clinical trials are demanding, but the challenges sponsors face are not insurmountable. By anticipating recruitment barriers, aligning on endpoints, preparing sites, planning for regulatory complexity, and managing resources wisely, sponsors can reduce risk and improve the likelihood of delivering meaningful results for patients.