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NCT03970733 · ClinicalTrials.gov registry record · Phase 2
Alternative Schedule Study For VLA15, a Vaccine Candidate Against Lyme Borreliosis
A Phase 2 study, sponsored by Pfizer.
- Completed
- Registry status
- Phase 2
- Development phase
- 246
- Enrollment target
NCT03970733: Completed Phase 2 study, sponsored by Pfizer.
NCT03970733 is a Phase 2 study that has completed, run by Pfizer. The registered enrollment target is 246 participants, above the 133-participant average among 30,622 other Phase 2 trials with a reported enrollment target (85% higher). According to ClinicalTrials.gov, the official US trial registry.
The verdict
NCT03970733, a Phase 2 study, has completed, sponsored by Pfizer.
- COMPLETED
- Registry status
- Phase 2
- Development phase
- 246 participants
- Enrollment target
Study Summary
In the Main Study Phase a total of 246 subjects were randomized 2:2:1 into three treatment groups to receive either VLA15 with Alum (lower or higher dose) or Placebo. Main Study Phase vaccinations were administered as intramuscular injections on Day 1, Day 57 and Day 180. In the Booster Phase subjects from the higher dose group who completed their primary immunization schedule according to protocol will be randomized 2:1 to receive an additional higher dose VLA15 vaccination or Placebo at Month 18. Study duration in the Main Study Phase per subject is a maximum of 20 months. Overall study Duration is estimated to be 22 months. Study duration per subject in the Booster Phase is a maximum of approximately 13 months. Study duration per subject in the Main Study Phase and Booster Phase together is estimated to be a maximum of approximately 33 months. Overall study duration (i.e., First-Subject-In to Last-Subject Out/ end of Booster Phase) is estimated to be approximately 37 months.
Primary Outcome
Geometric Mean Titers (GMTs) for Immunoglobulin G (IgG) against each Outer Surface Protein A (OspA) serotype ST1 to ST6, determined by Enzyme-Linked Immunosorbent Assay (ELISA) at Day 208 (Month 7)
Interventions
- BIOLOGICAL Placebo
- BIOLOGICAL VLA15
Trial Details
| Field | Value |
|---|---|
| Enrollment Target | 246 participants |
| Start Date | 2019-07-01 |
| Est. Completion | 2022-03-28 |
| Phase | Phase 2 |
What the finished NCT03970733 record still lists
NCT03970733 is an interventional study that assigns participants to a tested intervention. The registered 246 participants enrollment target is mid-sized for trials with a published cap, above the 133-participant average among 30,622 other Phase 2 trials with a reported enrollment target (85% higher).
The record links to 0 conditions, and to 2 interventions - of which Placebo is the first listed.
NCT03970733 does not publish any study locations in the registry export this page uses.
Frequently Asked Questions
What is clinical trial NCT03970733 about?
NCT03970733 is a clinical study titled "Alternative Schedule Study For VLA15, a Vaccine Candidate Against Lyme Borreliosis". In the Main Study Phase a total of 246 subjects were randomized 2:2:1 into three treatment groups to receive either VLA15 with Alum (lower or higher dose) or Placebo. Main Study Phase vaccinations were administered as intramuscular injections on Day 1, Day 57 and Day 180. In the Booster Phase subje...
What is the current status of trial NCT03970733?
This trial is currently completed. It is a Phase 2 study. The enrollment target is 246 participants. The study started on 2019-07-01. Estimated completion is 2022-03-28.
What interventions are being tested in trial NCT03970733?
The interventions under investigation include: Placebo (BIOLOGICAL), VLA15 (BIOLOGICAL).
Who is sponsoring clinical trial NCT03970733?
This trial is sponsored by Pfizer, which has 1,845 total clinical trials registered on ClinicalTrials.gov.
Learn More About Clinical Trials
How this trial's enrollment target compares
Where NCT03970733's enrollment target sits among peer trials
246 234th of 2000 higher than 1,767 of 2,000 other Phase 2 trials
participants (enrollment target), bucketed by value
Each bar is a band; taller bars hold more other Phase 2 trials. The dashed line + filled bar mark this entry. Hover or tap any bar for its full count and share, and where it sits relative to this entry.
Source ClinicalTrials.gov registry export · 2026-08-08
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