A study of ofatumumab with CHOP chemotherapy for Richter's syndrome (CHOP-OR)

Cancer type:

Blood cancers
Chronic leukaemia
Chronic lymphocytic leukaemia (CLL)
High grade lymphoma
Non-Hodgkin lymphoma




Phase 2

Chronic lymphocytic leukaemia (CLL) can sometimes develop into a condition called Richter’s syndrome. Richter’s syndrome is a type of high grade Open a glossary item lymphoma.

Cancer Research UK supported this study.

More about this trial

A combination of chemotherapy drugs called CHOP is the usual treatment for Richter’s syndrome. You might also have a drug called rituximab. This treatment can help to improve symptoms, but the lymphoma often comes back.

In this trial, researchers looked at a drug called ofatumumab. It is a type of targeted cancer drug (a biological therapy) called a monoclonal antibody similar to rituximab. 

People who took part in this study had ofatumumab with CHOP chemotherapy to get rid of the lymphoma. This is called induction treatment. They then had more ofatumumab on its own to try and stop the lymphoma coming back. This is called maintenance treatment.

The aims of the trial were to:

  • see if CHOP chemotherapy and ofatumumab helped people with Richter’s syndrome
  • learn more about the side effects

Summary of results

The study team found that adding ofatumumab to CHOP didn’t improve the treatment outcomes for people with Richter’s syndrome. 

This was a phase 2 study. Of the 43 people who took part, the team were able to look at the results of 37.

The researchers looked at how well CHOP with ofatumumab had worked for Richter’s syndrome. They found that for:

  • 10 of the 37 people (27%) there was no sign of Richter’s syndrome (complete response Open a glossary item)
  • 7 out of 37 people (19%) their Richter’s syndrome had reduced (partial response Open a glossary item)

When they looked at the average length of people were free of Richter’s syndrome after treatment it was just over 6 months.

The average length of time people lived after treatment was just under 11 ½ months. 

The most severe side effects reported were:

  • a drop in blood cells
  • feeling or being sick
  • high temperature (fever)
  • infections 
  • skin reactions

The study team concluded that adding ofatumumab to CHOP and giving it as maintenance treatment didn’t work better than rituximab to control Richter’s syndrome.

But the team found that they could use CHOP with rituximab as the best treatment (control group Open a glossary item) that they can test new treatments against in a clinical trial for people with this cancer. 

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.

Recruitment start:

Recruitment end:

How to join a clinical trial

Please note: In order to join a trial you will need to discuss it with your doctor, unless otherwise specified.

Please note - unless we state otherwise in the summary, you need to talk to your doctor about joining a trial.

Chief Investigator

Dr Anna Schuh

Supported by

Cancer Research UK
Experimental Cancer Medicine Centre (ECMC)
GlaxoSmithKline (GSK)
NIHR Clinical Research Network: Cancer
University of Oxford

Other information

This is Cancer Research UK trial number CRUKE/09/038.

If you have questions about the trial please contact our cancer information nurses

Freephone 0808 800 4040

Last review date

CRUK internal database number:


Please note - unless we state otherwise in the summary, you need to talk to your doctor about joining a trial.

Last reviewed:

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