Ibrutinib/Imbruvia and low antibody

[prichman]

The NYTimes article cited Imbruvica and low antibody reading, but it's information was sparse. Does Imbruvica reduce response or do people who need Imbruvica have lower responses? Does anyone know?

[annmcgowan]

Hi I don’t think ibrutinib impacts antibody reaction. It is more likely the CLL. I find the whole antibody testing issue baffling. People are going for testing but my haematologist advised me not to. He says they do not know how to analyse the tests well enough yet so we can’t rely on a positive or negative result. Neither do the tests indicate T cell responses.

So far I have followed his advice but am intersected in other peoples opinion.

Ann

[AussieNeil Administrator]

All CLL treatments reduce B-lymphocyte counts, both CLL cells and healthy B-lymphocytes. You need new, healthy B-lymphocytes to respond to vaccinations and mature into plasma cells which make antibodies. Imbruvica/Ibrutinib doesn't have as strong an impact on your immunity as some treatments. The anti-CD20 monoclonal antibody treatments (Rituximab, Obinutuzumab, Ofatumumab, etc), keep on killing off B- lymphocytes for up to a year after your last infusion. Ibrutinib seems to improve T-lymphocyte function, which is also important in vaccination response.

Neil

[cajunjeff]

I think the answer is that being on ibrutinib, or any other btk inhibitor, suppresses B cells necessary for creating an immune response. Therefore, on average, people on btk therapy do not show as robust an antibody response to covid vaccines as others do.

Doctors nevertheless recommend people on btk inhibitors get vaccinated for covid because the mechanism of how the vaccines help is not fully known. Just because one has a low antibody response to the vaccine does not mean the vaccine is not providing protection against severe disease from covid.

I do not think, as a matter of course, doctors are advising people to pause btk treatment just to get the vaccine though.

Some people conclude lack of antibody response to a Covid antibody test means no protection has been provided by the vaccine, but that might not be the case. We will not know for sure until we see how many people who have Cll and have been vaccinated end up getting covid and among those, how many have severe cases.

[prichman in reply to cajunjeff]

Helpful. My Dr said the Vaccine clinical trials did not have a CLL cohort, but did have high blood pressure and heart patients. So data is still lacking, as you say. Somehow, in my imagination I've thought that Imbruvica suppressed bad B-cells, but left good B-cells to do their job. Apparently, not a good as my (normal) wife's.

[lankisterguy Volunteer]

We had a similar discussion yesterday- some of the replies might be useful: healthunlocked.com/cllsuppo...

Len