EMN 2021 | Myeloma & infection risk: a constant threat

I spoke about infections in patients with multiple myeloma and I was very happy that the organizers have put that topic on the program because it is very important and physicians dealing with myeloma patients will agree with me that infections are common and can be very serious in patients with myeloma. Literature has learned us that it is the second most common cause of death after the disease itself.

Infections can occur at any time during the disease course of myeloma, but they are most frequent at the time of diagnosis and at the time of refractory relapse. And the early mortality in newly diagnosed multiple myeloma patients can be as high as more than 10%, and fairly frequently, that is caused by infections.

When it comes to the type of infections, so this can be bacterial, this can be viral, and sometimes there can also be infections with fungal agents. Of course, we do know that infections are frequent, but then, question is how to treat them and how to prevent them.

So, let’s start with prevention. Prevention, of course, is related to vaccination and that is a very actual topic these days, when we are still, every day, confronted with COVID-19 highly influencing our way of life. So, it’s clear that we should try to vaccinate as many myeloma patients as possible against flu during the flu season against primococci. And ideally, we should do that at a time when the disease is not being treated, for instance, at the stage of MGUS or smoldering multiple myeloma or during a plateau phase. But that’s, of course, not always possible.

When it comes to COVID-19, several studies have proven that the death rate of myeloma patients infected by COVID-19 can be as high as up to 30%. So, it is of high interest that we try to vaccinate as many patients as possible, of course, with an inactivated vaccine.

There are some guidelines being developed: what to do with the treatment? But very briefly, with the exception of patients that have received a stem cell transplant or CAR-T, where it is recommended to postpone the vaccination for at least three months. In all other situations, we can vaccinate our patients because the risk of not being vaccinated is higher than being vaccinated and having a sub-optimal antibody response. But it is also recommended to discontinue the dexamethasone treatment just before and just after the COVID-19 vaccination.

And then other vaccines like hepatitis, well, of course, they are depending on the specific serological situation of the patient. There is also a new vaccine against shingles. Also, here it is recommended when it’s available to use it as much as possible. And other ways of preventing infections, or for viral infections with herpes, so what we see more frequently with proteasome inhibitors and also for patients receiving monoclonal antibodies. There we should put the patient on prophylactic treatment.

When it comes to prevention of bacterial infections, there the question is, which group of patients should benefit from prophylactic antibiotic treatment? And there are some risk stratification models that have been developed for newly diagnosed patients, for patients treated with daratumumab. These risk factors, or these algorithms, have learned us that elderly patients, patients with poor performance status, patients with very active disease, they are at highest risk for developing bacterial infections, and particularly in this subgroup of patients. It can be of high clinical benefit to put these patients on prophylactic antibiotic treatment, for instance, with levofloxacin.

And then, when it comes to treatment of infections, of course, this is depending on the specific situation of the patient. But we should have a low threshold for prompt initiation of highly active antibiotic treatment when the patient is highly immunocompromised. When it comes to immunoglobulins in some countries, they are available, they are being used, but the evidence comes from studies from decades ago and it’s time to update the indications for immunoglobulins in myeloma.

In conclusion, it is beyond any doubt that infections are frequent, can be serious, and are a major cause of death in multiple myeloma. A good treatment of infection starts with knowing what are the most common pathogens, when do they occur, how to prevent them, and how to treat them optimally when an infection has occurred.