Fungal & bacterial infections

In this daily highlights video, Dr Doris Ponce from the Memorial Sloan Kettering Cancer Center in New York shares the results of 3 key abstracts presented in the oral abstract session on bacterial and fungal infections during the 2025 annual EBMT meeting in Florence.

Bloodstream infections (BSI) are common following an allogenic stem cell transplantation (alloSCT) and often arise following pathogen domination of the intestinal microbiome in the setting of a gastro-intestinal (GI)-barrier dysfunction. SER-155 is an investigational, oral live biotherapeutic comprised of 16 bacterial strains that is designed to prevent BSI and infection-associated events. During EBMT 2025, results were presented for cohort 2 of a phase 1b study evaluating SER-155 in adults undergoing an alloSCT. In this cohort, 34 patients were randomized between 10 days of SER-155 (preceded by 4 days of vancomycin) administered in 2 courses (pre-SCT and post-neutrophil engraftment) or placebo. The study revealed that most SER-155 strains successfully engrafted in the GI tract and demonstrated that this treatment was generally well-tolerated, without any serious adverse events. Compared to placebo, the SER-155 treatment resulted in a clinically meaningful and significantly lower incidence of BSI (10% vs. 43%; p= 0.0423), fewer days in the hospital and less antibiotic use.¹

The second study evaluated the impact of pre-transplant pharyngeal colonization on alloSCT outcomes.² This prospective clinical study involved 128 patients who underwent an alloSCT at a single center in China. Before conditioning, all patients underwent pharyngeal and rectal swab tests to identify colonizing pathogens. Interestingly, patients with Enterobacter colonization were found to have a higher incidence of post-transplant BSI (39.1% vs. 19.0%, p= 0.034) and veno-occlusive disease (VOD) or thrombotic microangiopathy (TMA) (17.4% vs. 8.5%, P = 0.04). In addition, these patients were shown to have a reduced overall survival (OS), an increased non-relapse mortality (NRM), and a worse progression-free survival (PFS) (p= 0.009, 0.0037, and 0.0046, respectively) compared to patients without Enterobacter colonization.²

Pentaglobin®, an IgM-enriched immunoglobulin, is known to enhance antimicrobial activity when used in association to antibacterial therapy. In the PENTALLO study, investigators assessed the impact of combined Pentaglobin® and antibacterial therapy on infection-related mortality in patients undergoing an alloSCT. This prospective study enrolled 121 adult patients affected by acute leukemia who received either intensive chemotherapy (N=11) or underwent an alloSCT (N=108). Patients were either colonized with or suffered a previous BSI by carbapenem resistant Enterobacteriaceae (CRE) or any Pseudomonas aeruginosa (PA) during the three months preceding hematological treatment. At the onset of neutropenic fever, patients received Pentaglobin® (5 ml/kg qd on three consecutive days) in combination with antimicrobial treatment active against the multidrug resistant (MDR) colonizing strain. Early results of this trial showed that the Pentaglobin® treatment is well-tolerated in this hematological setting. Furthermore, the combination of Pentaglobin® and targeted antimicrobial therapy reduced both the early (30-days) and late (4 months) mortality rate, resulting in an increased OS for patients colonized with MDR, gram-negative pathogens.³