Extensive Finnish Study Offers New Insights into Infection Risk and Mortality in Multiple Myeloma

Multiple myeloma significantly increases the risk of infections. A recent real-world evidence (RWE) study revealed that multiple myeloma (MM) patients experience more infections compared to healthy controls, even prior to diagnosis. Infections, both before and after diagnosis, were associated with an increased mortality.

Patients with multiple myeloma are particularly prone to infections, which are a clinically significant cause of mortality in this patient group. Both the disease itself and its treatments weaken patients’ immune systems. The recent study highlights the infection burden in multiple myeloma patients and its connection to mortality. It emphasizes the importance of preventing infections in this population.

The RWE study, conducted by Medaffcon and Takeda, included all multiple myeloma patients diagnosed in Finland between 2000 and 2021. The cohort consisted of over 7,000 patients and over 21,000 controls. The data were collected from several national healthcare registers. The median age of the patients at the time of diagnosis was 71 years.

The study revealed that multiple myeloma patients experienced higher infection rates compared to controls even prior to diagnosis. 

“We analyzed patient data over the three years prior to diagnosis. The difference in the number of infections between all patients and the control group was significant during the year before diagnosis. Among patients under 70 years old, significantly more infections were observed compared to the control group already three years before the myeloma diagnosis,” explains Essi Havula, Scientific Advisor at Medaffcon.

Even a Single Pre-Diagnosis Infection Shortened Survival Time

Anna Anttalainen, a data scientist at Medaffcon, utilized Cox proportional hazards modeling to show that even a single infection prior to diagnosis reduced survival times. 

“An infection diagnosis before and after the myeloma diagnosis was associated with a higher risk of mortality,” says Havula.

The study also categorized different types of infections. The risk of sepsis and pneumonia caused by Streptococcus pneumoniae increased during the three years leading to diagnosis.

“Post diagnosis, there was a notable increase in unspecified bacterial infections,” Havula adds.

The highest infection rates were observed following the diagnosis of multiple myeloma, likely due to the initiation of intensive treatments. In patients who received stem cell transplantation, the number of infections during the first two years post diagnosis was significantly higher than those treated without cell transplantation.

Surprising findings

The corresponding author of the study, hematologist Mervi Putkonen from Turku University Hospital (Tyks) says she was surprised by the research findings, even though it is known that multiple myeloma carries a significant risk of infection.

“The advancement of treatments and the increased use of immunological therapies have significantly improved treatment outcomes but have also increased patients’ susceptibility to infections”.

According to Putkonen, pneumococcal, influenza, and COVID vaccines are recommended for myeloma patients in Finland. After a stem cell transplantation, patients follow the vaccination program recommended by the Finnish Institute for Health and Welfare (THL). Additionally, patients undergoing myeloma treatment routinely use herpes and shingles prophylaxis, while a small proportion receive immunoglobulin replacement therapy.

Recent real-world evidence (RWE) findings further highlight the importance of effective infection management. 

“While treatment practices remain unchanged, it is crucial to emphasize the importance of including infection symptom monitoring in patient education. Patients should be reminded to promptly contact healthcare services if they develop a fever. In primary care, it is essential to manage infections in myeloma patients effectively and consult specialized care without delay,” Putkonen notes.

Read more:

A real-world study on the impact of infection load on mortality in multiple myeloma patients in Finland. Anttalainen A, Havula E, Kysenius K, Toppila I, Miettinen T, Lassenius MI, Silvennoinen R, Partanen A, Putkonen M. Annals of Hematology (2024).

Find more RWE study summaries here.