What Every STI Test Developer Should Know About FDA Clinical Trials
The field of sexually transmitted infection (STI) diagnostics is experiencing a significant shift. Advances in technology are driving testing out of centralized laboratories and into near-patient and at-home settings. Notably, the recent FDA authorization of the first over-the-counter (OTC) STI test marks a major milestone, highlighting the evolving landscape of STI screening and expanding access to care.
This evolution holds promise for reducing delays in treatment, minimizing the stigma surrounding STI testing, and expanding access to high-risk or underserved populations. As more companies enter the market, the ability to successfully navigate FDA clinical trials becomes a critical component of any go-to-market strategy
At MDC Associates, we specialize in the design and execution of FDA-regulated clinical trials for in vitro diagnostics. While STI studies are often resource intensive, a strategically designed trial can streamline enrollment, control costs, and accelerate time to market. Based on our experience supporting a variety of STI programs, here are six essential considerations for any developer preparing for an FDA clinical trial:
1. Specimen Type Selection
What sample types will you include in your intended use claim? Options often include urine, vaginal swabs, penile swabs, or a combination of these. Your decision will directly impact study enrollment, and the number of subjects needed. Each specimen type presents unique logistical and recruitment challenges.
2. Prevalence Realities
Despite clinical demand, the prevalence of key STI pathogens remains relatively low in the U.S. According to the CDC, recent data show prevalence rates of:
- Chlamydia: 495 cases per 100,000 persons
- Gonorrhea: 179.5 cases per 100,000
- Syphilis: 61.3 cases per 100,000
Targeted site selection and recruitment strategies are essential. Prioritize clinical sites that routinely test higher-risk populations and understand that positive specimens from standard-of-care testing are often unusable due to proprietary transport media.
3. Drug Resistance Testing
If your assay includes antimicrobial resistance detection, particularly for Neisseria gonorrhoeae, where resistance rates are increasing, access to viable bacterial cultures will likely be necessary. This requirement introduces added complexity, as most clinical sites utilize molecular methods that inactivate the organism. To address this, it is essential to plan for specialized specimen collection protocols, secure sources of resistant isolates, and coordinate with reference laboratories equipped to handle and culture these organisms.
4. Reference Testing Strategy
FDA requires a composite comparator method consisting of three FDA-cleared molecular assays: two runs on all specimens and a third as a tie-breaker. Early coordination with qualified reference laboratories is critical to avoid delays and prevent site-level testing errors.
5. Timelines and Study Size
STI trials tend to be longer than standard IVD studies. IRB review and contracting can be prolonged due to the sensitive nature of the testing. Additionally, study enrollment often ranges from 2,500 to 6,000 subjects to meet FDA’s positive specimen requirements, especially for low-prevalence targets.
6. Clinical Site Strategy
To achieve enrollment targets efficiently, we recommend engaging at least 10 clinical sites. This requires increased coordination, site management, and robust CRA support to ensure consistency across locations and to maintain study integrity.
Partner With MDC Associates on Your STI Diagnostic Program
Building the right study from day one can significantly influence the success of your program. MDC Associates brings decades of experience in STI diagnostics, regulatory strategy, clinical trial management, and FDA submissions. Whether you’re developing a professional-use assay or planning an OTC pathway, we can help you avoid costly missteps and move forward with confidence.
Visit our website at www.mdcassoc.com to learn more.
Contact us at bd@mdcassoc.com to schedule a discovery call and begin mapping out your regulatory and clinical strategy today. Let’s bring your STI diagnostic to the patients who need it most.
Why MDC Associates?
- Accelerated Path to Market: Over 35 years of IVD expertise across a broad range of technologies and applications, guiding you through regulatory and clinical processes efficiently.
- Regulatory Expertise with Continuous FDA Engagement: Our established, positive relationship with the FDA helps you navigate submissions like Pre-subs, 510(k), De Novo, and PMAs smoothly.
- Practical Quality Expertise: We help you achieve your quality objectives without overwhelming your team with too much too soon. From eQMS to MDSAP and ISO audits, get expert advice and hands-on support.
- Extensive Clinical Site Network: Access a trusted network experienced in supporting high-complexity assays, CLIA-waived tests, and OTC diagnostics, providing fast and reliable performance validation.
- Your Trusted IVD CRO: Beyond strategy, we work as part of your team to execute critical steps in regulatory submissions, clinical trials, and quality systems compliance.
