A 3-week pause versus continued Bruton tyrosine kinase inhibitor use during COVID-19 vaccination in individuals with chronic lymphocytic leukaemia (IMPROVE trial): a randomised, open-label, superiority trial

Background

Chronic lymphocytic leukaemia (CLL) is the most common type of leukaemia and weakens the immune system. New treatments, called Bruton tyrosine kinase inhibitors (BTKi), have greatly improved how we manage CLL. However, these treatments can reduce the body’s response to vaccines, including those for COVID-19.

Study Purpose

This study aimed to find out if taking a 3-week break from BTKi treatment before getting a COVID-19 booster vaccine would help improve the immune response to the vaccine while still keeping CLL under control.

Study Design

We conducted a trial with participants from 11 hospitals in the UK. Adults with CLL who had been on BTKi treatment for at least a year were included. Participants were randomly divided into two groups: one group paused their BTKi treatment for 3 weeks before vaccination, while the other group continued their treatment as usual. We measured the effectiveness of the vaccine by checking antibody levels in the blood three weeks after vaccination.

Findings

A total of 99 participants were included in the study. Those who continued their BTKi treatment had a higher average antibody level after vaccination compared to those who paused their treatment. However, the difference was not significant, meaning that pausing the treatment did not improve vaccine response.

Conclusion

The study suggests that taking a break from BTKi treatment around the time of vaccination does not help improve immunity to COVID-19 and should not be recommended in clinical practice.