Rare disease · oncology · gene therapy · pediatrics

External control arms, built for approval.

When you can’t randomize, the control arm is the submission. We design, build, and defend external control arms, hybrid designs, and small-sample trials for programs that cannot randomize — rare disease, oncology, gene therapy, pediatrics — with synthetic controls taken through NDA, Bayesian methods in rare disease, and natural-history comparators built to agency standard. Statisticians with a minimum of 15 years of regulated-industry experience.

NDA
Synthetic control arm, submitted & approved
15+
Years per statistician, regulated industry
48h
Feasibility review turnaround
Natural-history population 4,812
Matched external control 118
Your trial · treated 24
Every point is a patient. The comparator is selected, matched, and locked to your protocol.
External control armsNatural-history comparatorsBayesian borrowingPropensity & doubly robust adjustmentTipping-point sensitivityNDA / BLA statisticsEstimands · ICH E9(R1)Target-trial emulation
Programs we serve

Built for the trials that cannot randomize.

Too few patients, no ethical placebo, an accelerated pathway, a therapy that changes the disease course. The agency still needs a comparator it believes — in rare disease, in oncology, in gene therapy, in pediatrics. That comparator is what we build.

Rare disease · neuromuscular

DMD and rare neurology

Natural-history comparators for exon-skipping, gene therapy, and small-molecule programs where placebo is unethical and every patient counts.

Cell & gene therapy

Single-arm by nature

CAR-T, AAV, and ex-vivo programs where the external control decides the label — from first-in-human dose escalation to BLA.

Oncology

Accelerated to confirmatory

Prior-trial and real-world comparators for single-arm oncology programs, built to the precedent the agency has already accepted.

Pediatrics · platform · hybrid

Every patient informative

Pediatric extrapolation, platform trials, and hybrid designs that augment a small randomized control with external data — Bayesian borrowing that learns fast from few patients.

Method

From “we can’t randomize” to an approvable comparator.

The sequence the FDA’s externally controlled trials guidance and EMA reviewers expect to see — run end to end, reproducible end to end.

01
Source the comparator

Natural history, registries, EHR, prior trials — selected for fit to your eligibility, era, and endpoints.

02
Frame the estimand

Treatment effect, population, index date, and intercurrent-event strategy under ICH E9(R1), pre-specified.

03
Match & adjust

Eligibility alignment, propensity and doubly robust adjustment, Bayesian borrowing where the prior is defensible.

04
Stress-test

Tipping point, E-values, alternative comparators — every question the reviewer will ask, answered before it is asked.

05
Defend at the agency

Briefing document, meeting package, and the statistician in the room.

Practices

Four practices. One outcome: an approvable submission.

Fixed-fee engagements with defined scope. Each begins with a signed analysis plan and ends with documentation an agency reviewer can follow line by line.

External Control Arm Design & Analysis
Lead practice

Comparator source selection, eligibility alignment, propensity and doubly robust adjustment, Bayesian borrowing, and the full sensitivity suite — tipping point, unmeasured confounding, index-date alignment.

Delivered as a submission-ready package: protocol section, SAP, analysis, and the briefing-document argument.

Fixed fee per program
Scoped in 48 hours
Small-Sample & Bayesian Trial Design

Rare-disease, first-in-human, and platform designs: hierarchical and borrowing models, adaptive and group-sequential plans, estimand framing, and power by simulation — not by table.

Fixed fee
Scoped on request
Regulatory Statistics for NDA / BLA

Statistical sections of the submission, ISS/ISE, Type B and C meeting packages, responses to information requests, and the room-ready statistician at the agency meeting.

Fixed fee or retainer
Scoped on request
Real-World Evidence Studies

Comparative-effectiveness and natural-history studies from EHR, claims, and registry data — target-trial emulation, causal methods, and uncertainty quantification. Try the Conformal Engine →

Fixed fee
Scoped on request
Evidence

Randomized control vs. external control.

What changes when the comparator is external — and what the agency asks instead.

Randomized control armExternal control arm, built by InterClin AI
ComparatorEnrolled, randomized, concurrentNatural history, registry, EHR, or prior trials — matched to your protocol
Bias controlBy designBy method: eligibility alignment, propensity/doubly robust adjustment, index-date rules
Regulatory basisStandardFDA externally controlled trials guidance; precedent in rare disease, gene therapy, oncology
Sample sizeFull control arm enrolledControl patients largely external; every enrolled patient can be treated
What the agency asksWas randomization intact?Is the comparator credible? — answered in the sensitivity suite we pre-specify
Who has done itEveryoneStatisticians who have taken synthetic controls through an NDA
Track record

Done, not theorized.

The precedent record — every FDA approval built on an external control — and where our statisticians have been in it: Our experience →

Rare disease
Synthetic control arm taken through NDA
Rare disease
Bayesian methods in a rare-disease submission
Neuromuscular
DMD natural-history comparators
Cell therapy
CAR-T program from first patient
Real-world evidence
Oncology EHR comparator studies
Selected engagementsArtera AIIDEAYA BiosciencesBayer HealthCare
Free tools

See how we think before you hire us.

Justify

Sample size, adaptive design, and the write-up

Describe your study in plain English; validated formulas do the math; get an IRB- and protocol-ready justification, group-sequential plan, and DSMB outline.

Open Justify →

Conformal Engine

Guaranteed intervals on any model’s predictions

Upload calibration data, get statistically proven coverage intervals with empirical validation — the uncertainty quantification we use in RWE models. Runs in your browser.

Open the Engine →

About

Rare disease is where our statisticians have spent their careers.

InterClin AI is an independent statistical practice built for programs that cannot randomize. Every statistician on our engagements brings a minimum of 15 years in regulated industries — rare disease, neuromuscular and DMD, cell and gene therapy, oncology, and CNS — with synthetic control arms taken through NDA, Bayesian methods in rare-disease submissions, natural-history comparators, and FDA/EMA interactions from first-in-human to approval.

  • External control arms & synthetic controls — through NDA
  • Bayesian & small-sample rare-disease trial design
  • Natural-history comparators — DMD / neuromuscular
  • Statistical analysis plans, ISS/ISE, submission statistics (FDA/EMA)
  • Real-world evidence — target-trial emulation, causal methods
  • Uncertainty quantification & conformal prediction
Careers

Join the practice.

Senior statisticians with a minimum of 15 years in regulated industries, and the people who help sponsors find us. Remote, engagement-based.

Senior Biostatistician — External Controls
Lead comparator design and analysis for rare-disease and gene-therapy programs. Propensity, doubly robust, Bayesian borrowing; submission experience required. Apply
Bayesian Statistician — Small-Sample Design
Hierarchical and borrowing models, simulation-based operating characteristics, platform and FIH designs. Apply
RWE Epidemiologist
Target-trial emulation and natural-history studies from EHR, claims, and registry data for regulatory use. Apply
Statistical Programmer — R / SAS
CDISC-conformant derivations, TLFs, and reproducible analysis pipelines for submissions. Apply
Business Development — Rare Disease
Bring external-control and small-sample engagements to rare-disease and gene-therapy sponsors. Commission-based. Apply
Start

Send the protocol synopsis. Get the comparator plan in 48 hours.

A written read on comparator sources, matching strategy, regulatory precedent, and a fixed-fee scope for the full build — free of jargon, ready for your CMO.