Statistical Design Software
Stop paying $1,000+ for clunky desktop software. Run Group Sequential designs, Sample Size Re-estimation, CUPED, and Bayesian simulations for continuous, binary, and survival endpoints — directly in your browser.
499
Validation tests against gold standards
5
Real trial replications (NEJM, Lancet)
$99
Per month vs $4,995/yr for nQuery
Figure 1
O'Brien-Fleming Stopping Boundaries
Parameters
Output matches gsDesign R package v3.6.0
Figure 2
Conditional Power Zone Classification
Parameters
Zone classification per Mehta & Pocock (2011)
Figure 3
Blinded Sample Size Re-estimation
Parameters
Variance-based re-estimation per Zucker & Denne (2002)
Why Zetyra
Statistical engines built for the highest levels of scrutiny. Transparent, reproducible, and benchmarked against industry standards to support FDA- and EMA-ready trial design.
Eliminate “black box” calculations. Zetyra utilizes standardized R-backends for statistical legitimacy, providing full methodology transparency for your SAP.
Built for computational velocity. Run complex Monte Carlo simulations and adaptive design iterations at scale without legacy desktop latency.
Algorithms rigorously cross-validated against established standards, achieving numerical parity with industry-leading software.
Table 1
Validation Against Industry Standards
| Industry Standard | Parity Level | Guideline Alignment |
|---|---|---|
| Two-sample t-test (Satterthwaite) | Full Parity | Consistent with ICH E9 principles |
| GSD (O'Brien-Fleming) | Full Parity | Designed for FDA/EMA Stopping Rules |
| CUPED Variance Reduction | Full Parity | FDA Covariate Adjustment Guidance (2023) |
| Sample Size Re-estimation (Blinded & Unblinded) | Full Parity | FDA Adaptive Designs Guidance (2019) |
| Bayesian Toolkit (6 calculators) | Full Parity | FDA Draft Bayesian Guidance (2026) |
Optimize trial efficiency with Group Sequential boundaries and Sample Size Re-estimation. Use O'Brien-Fleming or Pocock stopping rules, blinded variance re-estimation, or promising zone methods — all for continuous, binary, and survival endpoints. Zetyra ensures that the preservation of the family-wise error rate is mathematically sound and fully reproducible.
Calculators
From basic power analysis to advanced adaptive designs.
View All CalculatorsVariance reduction using pre-experiment data
Save ~30% on sample size — that's 3,000 fewer subjects on a 10K trial
Interim analyses with stopping boundaries for continuous, binary, and survival endpoints
Stop failing trials early — save months of recruitment time
Blinded sample size re-estimation for continuous, binary, and survival endpoints
Adjust sample size mid-trial without unblinding — preserve Type I error
Promising zone re-estimation with inverse-normal combination test
Rescue underpowered trials with principled sample size increases
6 integrated calculators for continuous, binary, and survival endpoints
End-to-end Bayesian clinical trial design in one workflow
Power analysis for continuous, binary, and time-to-event endpoints
Get answers in seconds — no PASS license needed
Resources
Technical validation for biostatisticians. Business case for decision makers.
Step-by-step guides for each calculator
Updated March 2026
BrowseCUPED, GSD, SSR & Bayesian methodology
PDF · 42,000 words · 60 citations
Read6 modules, prior elicitation & sequential
PDF · 47 pages · 248 tests
ReadROI analysis for CUPED, GSD, SSR & Bayesian
PDF · 4 pages
ViewPricing
Start free. Upgrade when you need advanced features. Cancel anytime.
Competitor pricing
nQuery Pro: $4,995/yr
Zetyra Pro: $99/mo
Free
Pro
Recommended$29/mo for .edu
+ Bayesian Toolkit add-on from $49/mo
Team
5 seats included
Testimonials
Trusted by biostatisticians and clinical researchers to support rigorous trial design.
Zetyra was a great tool for our team to reassure us about our planned interim analysis for our clinical trial. The calculator helped inform our decision-making for our safety monitoring process to support trial integrity.
Kylie M.|Principal Investigator
We maintain an open-source validation suite with 499 automated tests across 25 scripts against industry gold standards. Our GSD module matches the gsDesign R package within 0.04 z-score units across 5 tested OBF/Pocock configurations (k=3–5). We validate survival/TTE endpoints against the Schoenfeld (1983) variance formula, Bayesian sequential boundaries against Zhou & Ji (2024), SSR against rpact (Kieser-Friede, Mehta-Pocock), and replicate published clinical trials (HPTN 083, HeartMate II, PACIFIC, MONALEESA-7). View our full validation suite at github.com/evidenceinthewild/zetyra-validation.
All 13 calculators use custom Python implementations built on NumPy and SciPy. GSD boundaries are validated against gsDesign (R) and rpact within 0.04 z-score units; SSR against Kieser-Friede and Mehta-Pocock; Bayesian methods against conjugate priors and Zhou & Ji (2024). All calculators support continuous, binary, and survival (time-to-event) endpoints.
Yes. Zetyra's calculations are validated against industry-standard references (gsDesign, rpact, published formulas) with 499 automated tests. Our Bayesian Toolkit aligns with the FDA's January 2026 draft guidance on Bayesian methods. For regulatory submissions, we recommend including the exported PDF report (which lists all parameters and version numbers) alongside your Statistical Analysis Plan.
Yes. Pro users can export professional PDF reports that include all input parameters, methodology citations, and results. Reports are designed to be included directly in your Statistical Analysis Plan for regulatory submissions.
Yes. Evidence Pro and above includes REST API access for programmatic use of all calculators. See our API documentation at zetyra.com/docs/api. For custom integrations or bulk workflows, contact sales@zetyra.com.
No. All plans are month-to-month. Cancel anytime with no questions asked.
Zetyra provides equivalent statistical accuracy—validated against gsDesign, rpact, and published formulas with 499 automated tests—at a fraction of the cost. PASS/nQuery offer broader legacy test coverage but require expensive desktop licenses ($6,000-$15,000/year). Zetyra offers 13 calculators covering modern clinical trial designs (GSD, SSR, CUPED, Bayesian Toolkit) across continuous, binary, and survival endpoints, runs in your browser with no installation, and enables easy sharing—starting at $99/mo.
We treat your designs as confidential. All data is encrypted in transit (TLS 1.3) and at rest. Input parameters are processed in real-time and not stored unless you explicitly save a project. We never use your data to train models or share it with third parties.
Evidence Collective ($349/month) includes 5 team seats, everything in Pro, a shared project library, team commenting and review features, and priority email support. It's designed for biostatistics departments that need to collaborate on trial designs. Additional seats can be added for $49/month each.
Yes! Academic users with a .edu email get Evidence Pro for just $29/month—70% off the standard price. This applies to graduate students, postdocs, and faculty. Sign up with your .edu email to automatically receive the discount.
If you cancel your Pro subscription, you retain access until the end of your billing period. Afterwards, your account reverts to the free tier. Your saved projects remain in your account as read-only (you can view and export them, but not edit).