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Synthetic and external control arms

Leverage the power of real-world data.

Are you designing a single arm trial in oncology or rare diseases? A synthetic control arm could give you the additional evidence you need to support regulatory submission.

The increase in single arm trials in oncology and rare diseases has created challenges when it comes to comparing treatments. In response, the use of synthetic and external control arms has grown dramatically, enabled by improved access to data including statistical toolkits from many research fields. But are they the answer and what benefits do they bring?

Synthetic controls

Synthetic and external control arms allow you to augment single arm clinical trial data without battling the ethical and numerical enrolment challenges of a placebo- controlled randomized control trial. They could help deliver the results you need with as few as 25 patients, with clear benefits for your trial design and budget:

Key Benefits

  • Reduce/eliminate the need to enrol control participants
  • Increase efficiency and lower trial costs
  • Reduce delays and speed life-saving therapies to market
  • Improve the chance of regulatory approval

We can give you the insights for regulatory success

Though synthetic controls in general are supported by regulators, the majority still fail to meet the criteria for clinical benefit. At Cytel we have 30 years’ experience of taking therapies from conception to commercialisation. We are experts at data sourcing, matching and processing to optimise synthetic control trial design and provide the valuable insights you need for success. Today we are one of the few companies with regulatory success in getting such applications approved in the market.

Advanced data analytics

We select optimal historical clinical data for your
synthetic control arm using real world advanced analytics (RWA) solutions and core principles from epidemiology.

Rigorous trial design

Our highly-skilled statisticians and data scientists employ advanced methods including Bayesian dynamic borrowing, propensity scoring, and quantitative bias assessment, to ensure historical data rigorously augments your trial.

Optimal patient allocation

Our forecasting engines identify what proportion of
your comparator arm should utilize historical data, helping you to optimize allocation of patients and avoid experiments on patients for marginal increases in scientific rigour.



Join Kristian Thorlund, SVP, Real World Analytics at Cytel introduces synthetic control arms and discusses the validity..
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eBook - Demystifying synthetic control arms

We take a closer look at the statistical techniques used in synthetic control arms.
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A Primer for Researchers

A guide to assessing synthetic controls with common challenges, real-life examples and a critical appraisal framework.
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Audio book

We demystify the techniques behind synthetic control arms.
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Is your trial a candidate for a synthetic control arm? Download our infographic to findout.
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Myth-busting webinar

Join four leading experts in the field as they help separate the myths about synthetic control from the reality.

Watch the webinar