VX19-445-116 A study of three CFTR modulator medicines for how well they work together and their safety in people with cystic fibrosis aged 6 to 11 with one F508del mutation and one minimal function mutation

A Phase 3b randomised, placebo-controlled study of the efficacy and safety of a triple combination therapy of elexacaftor (VX-445), tezacaftor and ivacaftor in people with cystic fibrosis aged 6 to 11 with one F508del mutation and one minimal function mutation

In order to take part in this study you will have one F508del mutation and one minimal function mutation, and be aged 6 to 11.

Elexacaftor (VX-445) is a medicine being studied for how well it works and how safe it is in people with cystic fibrosis. Your participation in this study will help us learn more about the safety of taking elexacaftor in combination with tezacaftor and ivacaftor.

All three of the medicines are CFTR modulators which means that they help the faulty CFTR protein to function properly. Tezacaftor is already approved for use and is what is known as a corrector. Ivacaftor is also already approved for use and is what is known as a potentiator. Elexacaftor is a corrector.

If you meet the rules for being in the study, you will take either:

• a combination of elexacaftor, tezacaftor and ivacaftor in the morning (in 2 tablets), and ivacaftor in the evening (1 tablet);

• or the same number of placebo tablets in the morning and evening.

You will not know whether you are taking the study medications or a placebo.

You will be asked to come into clinic around 9 times over up to 32 weeks. During visits, we will look for any changes in your health with bloods and other samples, vital signs and other investigations.

You will also receive 3 telephone consultations, each around half an hour, during this period. You do not have to come to clinics for these.