UK Haplo: a phase 2 study looking at the safety and effectiveness of allogeneic (donor) stem cell transplants using a partially matched donor in people with lymphoma and other blood cancers

This trial is looking at treatments for people having a donor stem cell transplant.


Purpose of trial

The aim of this trial is to find out if the chemotherapy drug cyclophosphamide can improve outcomes for people having a stem cell transplant using stem cells from a part-matched donor.

Some people with lymphoma and other cancers of the blood like leukaemia have stem cell transplants as part of their treatment.

Stem cell transplants can use stem cells from yourself (an autologous stem cell transplant) or from a donor (an allogeneic stem cell transplant).

Usually, your donor’s tissues are a very close match for your own. However, it is not possible to find a close match for about 1 in 3 people. In this case, doctors might suggest using a donor who is a 50% match (haploidentical or part-matched). The donor is usually a member of your family, for example your child or parent.

If the donor cells are part-matched rather than a very close match for your own cells, it is more likely that your immune system will recognise the donor cells as being from outside you. If this happens, your immune cells multiply and attack the donor cells, which causes serious side effects.

Other studies have shown that giving cyclophosphamide to kill your immune cells when they start to multiply could reduce the risk of serious side effects.


Treatments 

As part of your stem cell transplant, you have anti-cancer treatment including chemotherapy and whole body radiotherapy (total body irradiation). This is called ‘conditioning’. This treatment kills lymphoma cells and also kills the blood stem cells in your bone marrow.

After your conditioning treatment, you are given donor stem cells. The donor stem cells can move to your bone marrow and start making new, healthy blood cells.

There are 2 different treatment pathways in this trial. You and your doctor can discuss the options and decide which one is best for you. High-dose cyclophosphamide is given in both treatment pathways but at different times. The pathways for the 2 possible regimens in this trial are:

  • Reduced intensity pathway: chemotherapy with fludarabine and low dose cyclophosphamide, whole body radiotherapy, donor stem cells, high dose cyclophosphamide, immunosuppressive drugs (to prevent your body rejecting the transplant).
  • Full intensity pathway: whole body radiotherapy, donor lymphocytes (white blood cells that fight infection), high-dose cyclophosphamide, immunosuppressive drugs, donor stem cells.

If you have a full intensity regimen, you have donor lymphocytes (white blood cells that fight infection) as part of your treatment as well as donor stem cells. In this case, your donor must agree to have cells collected on 2 separate occasions.

For both pathways, you have the treatment in hospital and stay in hospital until your body has recovered from the transplant.

You continue to take immunosuppressive drugs for several weeks after you go home.

You have regular check-ups at the hospital after you go home (follow-up).

You are also asked to complete a questionnaire before your transplant, every 3 months for the first year after your transplant and 2 years after your transplant. The questions ask about any side effects you are having, and how well you feel (quality of life).


Who can enter

Your consultant can give you advice on whether this trial might be suitable for you.

A total of 78 people are needed for this trial.

You may be able to enter if:

  • You have lymphoma or another blood or bone marrow cancer.
  • You need an allogeneic stem cell transplant and don’t have a suitable matched donor.
  • You have a family member aged 16 or over who is at least a 50% match to your tissues.
  • You’ve had chemotherapy in the last 3 months. You may still be able to take part if you haven’t had this treatment but your doctor thinks you are suitable for a transplant.
  • You are well enough to mostly take care of yourself.
  • Your blood and other health test results are satisfactory.
  • You and your partner are willing to use reliable contraception during treatment and for at least 12 months after treatment if there is any chance of you or your partner becoming pregnant.
  • You are 16–70.

You will not be able to enter if:

  • A donor with a close match is available.
  • You’ve had an autologous stem cell transplant in the last 3 months.
  • You had a previous allogeneic transplant that wasn’t successful.
  • You have an infection that is not under control. You may still be able to take part if you have an infection but your doctor thinks you are well enough for a transplant.
  • You can’t have whole body radiotherapy.
  • You have any problems that your doctor thinks makes it unsafe for you to have the treatment.
  • You react against your donor’s cells in tests.
  • You are pregnant or breastfeeding.

Further information

More information about this trial is available at clinicaltrials.gov