A trial of pembrolizumab and rituximab for Waldenstrom's macroglobulinaemia (PembroWM)

Cancer type:

Blood cancers

Lymphoma

Non-Hodgkin lymphoma

Status:

Results

Phase:

Phase 2

This trial looked at pembrolizumab and rituximab for Waldenstrom’s macroglobulinaemia (WM). It was for people whose WM had come back after treatment or treatment had stopped working.

The trial was open for people to join between 2019 and 2022. The team published the results in 2024.

More about this trial

Waldenstrom’s macroglobulinaemia (WM) is a slow growing type of non-Hodgkin lymphoma Open a glossary item (NHL).

Doctors treat WM with a targeted cancer drug Open a glossary item called rituximab. They use it either on its own or in combination with chemotherapy drugs or other targeted cancer drugs.

Sometimes WM can come back during treatment. This is known as refractory WM. It can also come back after treatment has finished. This is known as relapsed WM. Researchers are looking for new treatments to help people in these situations.

Pembrolizumab is an immunotherapy drug Open a glossary item . It works by helping the immune system find and kill cancer cells. We know from previous clinical trials that pembrolizumab could help people with WM.

Researchers thought that the combination of pembrolizumab and rituximab might help people with WM that had come back or their treatment had stopped working.

The main aims in this trial were to find out:

how well pembrolizumab and rituximab works
how safe this combination is
what the side effects are
how it affects quality of life

Summary of results

This was a phase 2 trial Open a glossary item . All of the 17 people who took part had pembrolizumab and rituximab.

After 24 weeks of treatment the team looked at the number of people who had no sign of lymphoma (complete response) or the lymphoma had shrunk (partial response). They found that about half (47.1%) of them did.

At just over 13 and a half (13.6) months from when people agreed to go into the trial, half of the people were still alive and without their lymphoma having started to grow again. At 1 year after treatment, 16 people were still alive. At 2 years after treatment, 13 people were still alive.

During the trial 5 people died. Only 1 of these was directly due to lymphoma. The others were to do with infection, one because of another type of cancer and one from treatment they had after the trial treatment.

Side effects
Of the 17 people, 16 (94%) reported at least one side effect. The majority of them were mild. The most common were:

a drop in the red blood cells (anaemia )
a high temperature (fever)
tiredness (fatigue)
a raised level of creatinine in the blood
reactions while having the treatment
dizziness
a cough
low blood pressure
a drop in the while blood cells called neutrophils

13 people (77%) had more severe side effects. Infection was the most common.

Three people also stopped treatment due to side effects. Two due to infection and the other due to sweating more than normal.

We have information about the side effects of:

Quality of life
The team looked at the difference in quality of life Open a glossary item from when people started their treatment and at 24 weeks of treatment. Of the 17 people, they had this information from 9 at both time points.

When the team looked at the scores they use to measure quality of life, including symptoms, there was no difference or improvement in the majority of people. However, they did find an improvement in:

experience and expression of more positive feelings
thinking, remembering, decision making and attention

Conclusion
The team concluded that pembrolizumab can be given with rituximab to treat people with Waldenstrom’s macroglobulinaemia. They also say that adding pembrolizumab didn’t increase the number of side effects by much.

More detailed information
There is more information about this research in the reference below.

Please note, the information we link to here is not in plain English. It has been written for healthcare professionals and researchers.

PembroWM: A phase II trial to investigate the safety and efficacy of rituximab and pembrolizumab in relapsed/refractory Waldenström's Macroglobulinaemia
J Kothari and others
British Journal of Haematology, 2024, pages 0 to 9.

Where this information comes from
We have based this summary on the information in the article above. This has been reviewed by independent specialists (peer reviewed Open a glossary item ) and published in a medical journal. We have not analysed the data ourselves. As far as we are aware, the link we list above is active and the article is free and available to view.