Theratyping

Theratyping is a way to test in the lab which medicines might work best for people with certain cystic fibrosis transmembrane conductance regulator (CFTR) gene mutations. The main goal is to help people with rare CFTR mutations gain access to existing CFTR modulator treatments quickly and safely.

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Researcher using specialized instruments in CFFT Lab.

Summary

Theratyping can help care teams decide the best treatment for people with rare mutations, especially if their current modulator isn't working well or if they have a second mutation that has unclear effects.
If lab tests show that certain rare mutations respond to a CFTR modulator treatment, that information is shared with the drug's manufacturer.
The pharmaceutical company might use this information to help inform its own research into whether to apply to the U.S. Food and Drug Administration (FDA) to expand the label for a drug to new mutations.

Why Is Theratyping Important?

Usually, researchers test whether a medicine works for people with a certain CFTR gene mutation by running clinical trials. Clinical trials are feasible when there are enough people with that mutation to test, but this process becomes problematic for individuals whose mutations are so rare that only a handful of other people have them in the world. (About 1,000 CFTR mutations occur in fewer than five people.)

To help these people, researchers supported by the Foundation tested CFTR modulators — medicines that target the CFTR protein — on lab-grown cells with rare CFTR mutations. If those tests showed that a particular mutation responded to a modulator, the researchers shared that information with the drugs’ manufacturer to inform its own research into whether to apply to the U.S. Food and Drug Administration (FDA) to expand eligibility to a modulator to new mutations.

Theratyping Expands Access to Treatment

Since 2020, the FDA has used theratyping data from Vertex Pharmaceuticals to gradually approve CFTR modulators for more people with rare CF mutations. In April 2026, the FDA approved Trikafta (ages 2 and older) and Alyftrek (ages 6 years and older) for people with CF who have any CFTR mutation that produces a CFTR protein.

People with CF who want to know whether they are eligible for modulators should talk to their care teams first or consult Vertex’s Treatments Finder. To be eligible, you need to have at least one CFTR mutation that produces a CFTR protein.

The Foundation pays for theratyping tests at Cincinnati Children’s Hospital Medical Center for people with CF in the U.S. who have rare mutations. The center uses their nasal cells to see whether the cells respond to modulators. This testing can help care teams decide the best treatment for people with rare mutations, especially if their current modulator isn't working well or if they have a second mutation that has unclear effects. If you think you could benefit from this testing, consult your care team.

For more details about testing or referrals, contact John Brewington, MD, at john.brewington@cchmc.org.

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Topics

CFTR Modulators | Genetics | Research