Reviewing the Efficacy and Safety of Omadacycline in Immunocompromised Patients
In a new study presented at MAD-ID, omadacycline was found to have an 86% clinical success rate across a wide-range of infections and pathogens in an immunocompromised population.
In a new study presented at MAD-ID, omadacycline was found to have an 86% clinical success rate across a wide-range of infections and pathogens in an immunocompromised population.
“This is an effective antibiotic, particularly in this patient population,” study investigator Sean Van Helden, PharmD, Postdoctoral Infectious Diseases Pharmacotherapy fellow, Wayne State University, said.
The most common immunocompromising conditions included solid organ transplant (27%),cytotoxic chemotherapy (23%), and receipt of medications that suppress the immune system (23%). And the most prevalent infections included respiratory tract (27%), intra-abdominal (23%), skin and soft tissue (23%), and bone/joint (18%). The most common pathogens were Enterococcus faecium (32%), Escherichia coli (18%), Enterococcus faecalis (14%), Streptococcus anginosus (14%), Klebsiella pneumoniae (9%), and methicillin-resistant Staphylococcus aureus (9%).
Study Specifics
This was a multicenter, real-world, observational trial conducted from October 2018 to October 2023. Patients included were at least 18 years of age and had received the antibiotic for ≥72 hours. Both inpatient and ambulatory patients were considered eligible for the study.
The primary outcome was clinical success, defined as the absence of infectious symptom recurrence during treatment or within 14 days after completion of therapy. Secondary outcomes included 30-day all-cause and infection-related mortality, 30-day hospital readmission, and microbiological recurrence.
A total of 22 patients were included in the analysis. The median age was 62.0 years (interquartile range [IQR], 51.8–67.8 years). Most patients were male (59%) and White (82%).
Hospital readmission occurred in 27% of patients, with 14% of readmissions being infection-related. No patients died within 30 days of initiating omadacycline. Regarding adverse drug reactions, 18% of patients experienced gastrointestinal symptoms—none led to discontinuation of omadacycline. No other adverse effects were reported.
“It's encouraging to see that just 3 of those patients were readmitted for infection related reasons,” Van Helden said. “If this is something you're going to be taking long term, you want to minimize those adverse events. And the adverse event rate was low; Four patients experienced GI adverse events, and none of those led to drug discontinuation."
Van Helden points the wide-spread utility of the antibiotic in an oral format. “When these patients have these multidrug resistant infections, there's not a lot of oral options for them. In the case of VRE and MRSA, you have something like linezolid, which comes with a lot of drug interactions and toxicities, especially with prolonged duration,” he said. “And so it's great to have another oral option that patients can tolerate pretty well and has high clinical success rate. It's definitely encouraging and another option to add to our antibiotic armamentarium.”
He notes that omadacycline can be a valuable alternative for this patient population, which is vulnerable to frequent infections, multidrug resistance, and the toxicities of other antimicrobials.
“I think this is definitely a patient population in which there's interest in using the oral formulation of omadacycline,” Van Helden said. “This is something we consider when we need to provide long-term suppression, particularly in vulnerable patient populations,” Van Helden said. “I think it's something that people might not always think about as an option because it is newer—but I think it's something that we can begin thinking about. Hopefully we can minimize any toxicities that occur with antibiotics like linezolid, as well as prevent infections in these patients,” he said.
Although the results were promising, the investigators point out the limitations of a very small study sample size. “A larger sample size is necessary to corroborate these findings and potentially identify predictors of clinical efficacy with omadacycline in this patient population,” they wrote.
