How strong eligibility signals unlocked scale in Parkinson’s trials

Recruitment in genetically stratified clinical trials is often constrained by a simple problem: large screening volumes do not translate into eligible patients. Sponsors can process thousands of participants, yet only a small fraction meet protocol criteria after genetic testing. This creates delays, increases cost, and limits confidence in scaling recruitment programs.

This case study examines two Parkinson’s disease trials and shows how early identification of strong eligibility signals enabled faster progression from screening to dosing and supported mid-program scale-up.

The core challenge in genetic trial recruitment

In precision medicine studies, eligibility is typically confirmed only after genetic testing. This introduces several operational bottlenecks:

• High screening volume with low conversion to eligible patients
• Delays between prescreening, testing, and referral
• Uncertainty around whether additional testing will yield viable participants
• Difficulty scaling recruitment without clear evidence of downstream success

As a result, many programs optimize for activity rather than outcomes, focusing on the number of tests run instead of the number of patients who progress to dosing.

Approach: Designing for early eligibility signal detection

Across both programs, recruitment was structured to surface high-quality eligibility signals early and consistently. 

Key components included:

• Targeted outreach to pre-qualified patient populations
• Integration of at-home or on-site genetic testing workflows
• End-to-end participant management from prescreening through referral
• Tight turnaround times between each stage of the recruitment funnel
• Close alignment with clinical sites to enable rapid progression to screening and dosing

Recruitment, genetic testing, and participant management were coordinated as a single system rather than separate steps. This approach ensured that each stage of the pipeline generated actionable insight into whether patients were likely to meet protocol criteria.

Program A: GBA1+ Parkinson’s Disease

A top-10 global pharmaceutical company partnered with Sano Genetics to recruit for a Phase 2 trial targeting individuals with confirmed GBA1 mutations.

Key outcomes

• 19 GBA1+ participants identified within 4 months
• 85% of genetically confirmed participants referred to trial sites
• First genetically confirmed patient identified within 6 weeks
• 5 participants dosed to date

Operational performance

• Median 13 days from prescreener completion to kit shipment
• 76% of kits returned within 14 days
• Median 13 days from kit return to genetic result
• Referral to site within 7 days of result delivery

Impact on scale

Strong early signal quality provided confidence to increase testing volume. Kit allocation expanded by 94% during the program, reflecting consistent conversion from testing to eligibility.

Program B: Genetically stratified Parkinson’s disease

A neurodegeneration biotech company implemented a site-centered recruitment model for a Phase 2 trial targeting a narrow genetic subset of Parkinson’s patients.

Key outcomes

• Kit volume doubled from 600 to 1,200 during the program
• 44% of randomized patients originated from activated trial sites
• 16 participants dosed following genetic confirmation

Operational strategy

• Embedded patient identification into routine clinical workflows
• Enabled on-site genetic testing to reduce friction
• Established clear referral pathways and onboarding processes
• Delivered a coordinated virtual patient experience

Impact on scale

As sites generated higher-quality referrals, the sponsor increased testing capacity. Expansion was directly linked to demonstrated conversion into eligible and randomized participants.

What drives scale in genetically stratified trials

In both programs, early signal quality didn’t just improve recruitment; it informed confidence in eligibility criteria and testing strategy before full-scale rollout. Recruitment scaled when eligibility signal quality was proven early. 

High match rates and strong downstream conversion provided the evidence needed to:

• Increase testing volume
• Accelerate site activation and engagement
• Move patients more quickly from screening to dosing

Most recruitment programs optimize for volume; the programs that scale optimize for signal.

Key takeaways for clinical trial sponsors

Sponsors designing genetically stratified trials should prioritize:

1. Measuring hit rate early

Track the proportion of genetically confirmed patients who meet protocol criteria and are referred to sites.

2. Reducing time between stages

Shortening the interval between prescreening, testing, results, and referral improves overall throughput and patient retention.

3. Aligning recruitment with site workflows

Embedding identification and testing within clinical environments increases referral quality and conversion.

4. Scaling based on evidence

Expand recruitment only when data shows that additional testing will produce eligible participants.

Conclusion

In genetically stratified trials, success depends on how effectively recruitment systems identify eligible patients early in the process.

Programs that generate strong eligibility signals can scale with confidence, reduce time to dosing, and improve overall trial efficiency.

For sponsors, the critical question is not how many patients can be screened, but how quickly recruitment efforts can demonstrate that they are finding the right patients.

Download the full case study here.