COVID-19 and MPN patients (including CML): results of a study from Oxford

A study from Oxford University Hospital looking at the response to COVID-19 vaccines of patients with chronic myeloid neoplasms was published on 16th June 2021. The study was published as a letter in the British Journal of Haematology. In this blog, our Patient Advocacy Manager outlines the first reaction to the news and what the takeaway messages are for patients and their loved ones.

Key points:

  • If you look at people with chronic myeloid neoplasms (CML, MF, ET, PV and MDS patients), they are less likely to make antibodies to the COVID vaccines than people without blood cancers (58% of people with myeloid blood cancers vs. 100% of people without blood cancers).
  • This group of patients is also less likely to make as many antibodies as people without blood cancers (about 8.5 times fewer antibodies).
  • However, if you look at the different types of blood cancers individually, some patients are more likely to respond to the vaccine than others. The response also seems to depend on your treatment. Those on TKIs who have CML and MPN patients on interferon treatment are likely to respond well. Patients taking ruxolitinib were least likely to respond to the vaccine
  • We should be cautious in making too many conclusions from this study, as although a fairly big sample overall (62), there were small numbers of patients with each individual blood cancer type (e.g., only 12 had CML).
  • The study does suggest that there are differences in response based on your type of blood cancer and what treatment you receive, showing the need for research projects in a wide variety of patients.

A study from Oxford University Hospital looking at the response to COVID-19 vaccines in patients with chronic myeloid neoplasms was published yesterday (16th June 2021). The study was published as a letter in the British Journal of Haematology. This study compared people with myeloid blood cancers to healthcare workers who did not have a blood cancer diagnosis (this is known as a control group).

Cells of the blood can be divided into two main types: lymphoid and myeloid cells. Different blood cancers affect different blood cells. In this study, the researchers only tested the response of blood cancer patients with blood cancers affecting myeloid blood cells. This included 12 people with chronic myeloid leukaemia (CML), 17 people with essential thrombocythemia (ET), 7 people with myelofibrosis (MF), 11 people with polycythaemia vera (PV) and 13 people with a diagnosis of myelodysplastic syndrome (MDS). If you are looking for information about COVID-19 vaccine responses in other groups of blood cancer patients, please see our previous article on CLL here, an initial study across many blood cancers here or find the latest on lymphoma and myeloma the Blood Cancer UK website here.

The authors noted that this study was necessary as previous studies had failed to include many people with myeloid cancers. It is thought that patients with chronic myeloid blood cancers may be more likely to react to the vaccine than those with blood cancers affecting lymphoid cells. Many people with chronic myeloid blood cancers require less treatment and most have normal or near normal levels of other blood cells. This study aimed to see if these predictions were true.

The study involved testing blood samples of patients to see whether they had COVID-19 antibodies and if so, how many antibodies they had. They specifically only included people who had never had COVID-19 naturally, so they could be sure that the antibodies they were studying came from the vaccine. The study included both the Pfizer BioNTech vaccine and the Oxford AstraZeneca vaccine and found little difference between the two vaccines. Importantly, everyone in the study had only had one dose, meaning further study is needed to see what the reaction is in people with the full two doses.

As a whole group, the results show that whilst nearly 100% of the healthy control group had antibodies after the vaccine, only 58% of those with chronic myeloid blood cancers had antibodies. The study also compared the amount of antibody each group make; the healthy control group made nearly 8.5 times more antibodies than the group of patients with chronic myeloid cancers.

However, the authors noted that the story is not so simple. When each blood cancer type was looked at individually, certain groups were more likely to respond to the vaccine than others. These groups were CML patients on TKIs and MPN patients (ET, PV and MF patients) having interferon treatment.

30% of the people studied were on no treatment at the time of the study; everyone else was spread across a wide range of treatment options, including tyrosine kinase inhibitors (TKIs) for CML, chemotherapy like azacytidine for MDS, interferon treatment for ET or PV, and ruxolitinib, which is used for ET, PV and MF. CML patients were most likely to respond (75% of all CML responded, 5/6 people on imatinib), whilst nobody having ruxolitinib responded (0/4 people). Due to the small number of people with each blood cancer type, it is hard to say whether type of treatment was definitely affecting ability to respond to the vaccine. However, this does show that treatment might play a role and demonstrates why we need more research into a wide variety of blood cancer patients, so we can understand the whole picture.

It is important to remember that antibodies are not the only way your immune system can respond. T-cells are also important, and another study, published in May in the scientific journal Leukemia, showed that MPN patients having 1 dose of a Pfizer BioNTech vaccine also had a good T cell response. This too was only a small study.

Another reason to be careful in interpreting these results is that all these participants had only had one dose of the vaccine. It is known that two doses of COVID vaccines are needed for full protection; this applies to both people with and those without blood cancers. Therefore, whilst certain groups may have struggled to have a response, this does not mean that they didn’t achieve a good response after their second dose. We await further studies on two doses for these patients.

You can read the full study here.

Need advice or support about anything discussed in this article?

After a blood cancer diagnosis, it’s understandable that you or your loved ones will have questions. Our Nurse Advisors are available across a range of services to give you the expert advice you need, from diagnosis, to treatment and beyond. However, our nurses cannot diagnose or treat you over the phone. In case of an emergency, please contact your medical team or call 999.

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