Predicting Early Severe Infection in Patients With Newly Diagnosed MM

Nearly half of patients with multiple myeloma (MM) are at an intermediate or high risk of developing a severe infection within the first 4 months of diagnosis, and a simple risk score can identify those who might be candidates for prophylactic antibiotic therapies, according to a study published in Blood Cancer Journal.

The researchers conducted a post hoc analysis of infections in 1347 patients across 4 clinical trials from the Spanish Myeloma Group (Grupo Español de Mieloma or GEM) and identified the variables associated with increased risk of severe infection during the first 4 months to use with a simple risk score.

In addition to MM leaving patients vulnerable to viral and bacterial infections, new treatments might impact the immune system and increase the risk of infection.

“The incidence of severe infection in patients with MM seems to be higher during the first months after the diagnosis,” the authors noted. They added that “risk scores to predict the probability of infection could help in identifying patients at higher risk of infection who may benefit from individualized prophylactic antibiotic treatments.”

The patients included in the analysis were treated in 4 GEM clinical trials: GEM2005>65, GEM2010>65, GEM 2005<65, and GEM2012<65. Antibiotic prophylaxis was mandatory during the first 3 months of the GEM2010>65 trial, so it was not included in the final analysis, but the researchers were able to compare with GEM2005>65, which did not have mandatory prophylaxis.

The median age of the patients was 62 years, and the median follow-up with 81.7 months. The patients in GEM2005>65 and GEM2010>65 were 65 years or older and ineligible for autologous transplant, while the patients in the other 2 studies were younger than 65 years and transplant candidates.

In the first 6 months, 24.3% of patients experienced at least 1 infection. Of these patients, 74 had 2 infectious events, 19 had 3, and 7 had more than 3 events. Of the patients with an infection, 49.2% had at least 1 severe infection, which was 12.5% of the overall patient population.

The researchers found:

• 59.1% of infectious events were respiratory infections
• 8.7% were fever episodes
• 8.2% were urinary tract infections
• 2.8% were catheter infections
• 2.4% were bacteremia episodes
• The majority of infections—77.3% of all infections and 78.3% of severe infectious—happened within the first 4 months of treatments

Comparing patients in GEM2005>65 with GEM2010>65, which mandated antibiotic prophylaxis, the researchers found the incidence of early severe infection was higher among patients who did not receive prophylaxis (HR 2.57; P < .001).

Analyses of the patients who experienced severe infection within 4 months of initial treatment found variables all associated with higher risk of early severe infection in the first 4 months of treatment. In multivariate analysis, albumin of 30 g/L or less, Eastern Cooperative Oncology Group performance Status above 1, male sex, and non–immunoglobulin A MM type were all selected.

The researchers then generated a score to predict risk of infection and identified 3 risk groups: 8.2% were in the low-risk group (0-2 points), 19.2% in the intermediate-risk group (3 points), and 28.3% in the high-risk group (4 points). The study with the mandatory antibiotic prophylaxis was not used to generate the score. The probability of the low-risk group getting early severe infection was 8.2% compared with 20.6 for the intermediate-/high-risk groups.

“When the intermediate- and high-risk were grouped, the differences persist, so patients at intermediate/high risk are the ideal candidates to be treated with prophylactic antibiotics, although this should be validated in independent cohort studies,” they wrote.

The authors noted several limitations to the study, such as the heterogenous treatment regimens and characteristics of the patients. In addition, while antibiotic prophylaxis was not mandatory in the 3 trials used to generate the score, it was at the discretion of the participating center and the information on it was not collected.

Reference

Encinas C, Hernandez-Rivas J-Á, Oriol A, et al. A simple score to predict early severe infections in patients with newly diagnosed multiple myeloma. Blood Cancer J. Published online April 19, 2022. doi:10.1038/s41408-022-00652-2