It recruited 12 people who had already had treatment for their CLL. Everyone taking part had lenalidomide and dexamethasone.
Of the 12 people who took part:
- 4 people (33%) stopped treatment early because they had serious side effects
- 4 people (33%) stopped treatment early because their CLL got worse
When the research team looked at how well the treatment worked, they found that the leukaemia had:
- got a bit better in 3 people (25%)
- stayed the same in 2 people (17%)
- got worse in 7 people (58%)
They also looked at the side effects people had, and found that 11 out of 12 people had at least one severe side effect. The most common side effects were a drop in blood clotting cells (platelets) and a drop in white blood cells.
No one taking part had
tumour lysis syndrome (TLS) or
tumour flare reaction (TFR) 
, two possible serious side effects of higher dose lenalidomide.
The research team had hoped to be able to increase the dose of lenalidomide people had. They increased the dose a bit for 5 of the people taking part. But they had to reduce it back down or delay treatment for most of them, because of side effects.
The researchers concluded that low dose lenalidomide and dexamethasone could be useful for people who have already had treatment for CLL that is not working anymore. But that it can cause serious side effects, even at a low dose, in this group of patients. Adding dexamethasone did mean that people had fewer side effects than expected. But not so few that they could change to a higher dose of lenalidomide.
They recommend that more research is done to find out which patients are likely to benefit most and have the least side effects.
We have based this summary on information from the research team. The information they sent us has been reviewed by independent specialists (
peer reviewed 
) and published in a medical journal. The figures we quote above were provided by the trial team who did the research. We have not analysed the data ourselves.