A trial looking at obinutuzumab and rituximab for chronic lymphocytic leukaemia (CLL)

Cancer type:

Blood cancers

Chronic leukaemia

Chronic lymphocytic leukaemia (CLL)

Leukaemia

Status:

Results

Phase:

Phase 3

This trial looked at which treatment is better to help people with CLL who tested positive to the protein CD20 and who have other health problems.

People who took part were having treatment for CLL for the first time.

More about this trial

CLL is often treated with a combination of chemotherapy and biological therapy.

A chemotherapy drug often used is chlorambucil (or Leukeran). It works by sticking to the cancer cells DNA Open a glossary item so it can’t divide into 2 new cells.

Rituximab (or Mabthera) is a type of biological therapy. It sticks to a protein called CD20 on the surface of the leukaemia cells. The immune system Open a glossary item then picks out the marked cells and kills them.

Doctors also looked at a new biological therapy called obinutuzumab. It works in a similar way to rituximab. The researchers think that obinutuzumab might be better than rituximab.

In this trial people had 1 of the following:

chlorambucil
chlorambucil and rituximab
chlorambucil and obinutuzumab

The main aim of this trial was to find out which combination of treatment is better to help people with CLL who have other health problems.

Summary of results

The study team concluded that chlorambucil and obinutuzumab was the best combination of treatment to help people with CLL who have other health problems.

This was an international phase 3 trial. 781 people took part. As well as CLL people also had other health problems such as:

heart problems
high blood pressure
kidney problems
problems with muscles, joints and nerves (musculoskeletal)
problems with glands that produce hormones such as diabetes

This was a randomised trial. Everyone was put into 1 of the following treatment groups by computer:

chlorambucil
chlorambucil and rituximab
chlorambucil and obinutuzumab

Neither they nor their doctor could choose which group they were in. People were 2 times more likely to have chlorambucil and rituximab or chlorambucil and obinutuzumab than chlorambucil alone.

Results Diagram

Everyone had treatment in 28 day cycles. People had up to 6 cycles of treatment (around 6 months).

Chlorambucil
118 people took part in this group. Everyone had chlorambucil as tablets.

People had chlorambucil on the 1^st day (day 1) and day 15 of each treatment cycle. Then they had a break of 2 weeks.

This continued for as long as the cancer stayed the same and for up to 6 cycles of treatment. If the cancer got worse, people changed groups and had chlorambucil and obinutuzumab. This is called a cross over.

Chlorambucil and rituximab
Everyone had chlorambucil tablets and rituximab as a drip into a vein. 330 people took part in this group.

People had chlorambucil and rituximab on day 1 of each treatment cycle and chlorambucil again on day 15. This continued for as long as the cancer stayed the same and for up to 6 cycles of treatment.

Chlorambucil and obinutuzumab
333 people took part in this group. Everyone had chlorambucil tablets and obinutuzumab as a drip into a vein.

People had chlorambucil on day 1 and 15 of each treatment cycle. They also had obinutuzumab on days 1, 8 and 15 of cycle 1. After that, they had obinutuzumab on the 1^st day of each treatment cycle.

All treatment groups
The trial team looked at the side effects each group had. They found that people who had chlorambucil and obinutuzumab had more side effects than the other 2 groups. The most common side effects were:

a drop in the number of white cells (neutropenia)
infections such as chest infection
an allergic reaction
a drop in the number of red cells (anaemia)

The team also looked at how well treatment worked. To do this, they looked at the average length of time people lived without any signs of their cancer getting worse. This is called progression free survival. They found it was:

almost 27 months for people who had chlorambucil and obinutuzumab
around 16 months for people who had chlorambucil and rituximab
around 11 months for people who had chlorambucil

They also looked at the people’s quality of life Open a glossary item . They found this was the same in all groups.

So the trial team concluded that chlorambucil and obinutuzumab was the best treatment for people with CLL who have the CD20 protein and other health problems. But there were more side effects.

The team think that people having obinutuzumab for the 1^st time should be monitored closely because of the risk of an allergic reaction. This should be managed better in the future as nurses and doctors become more familiar with this treatment.

We have based this summary on information from the research team. The information they sent us has been reviewed by independent specialists (peer reviewed Open a glossary item ) 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.