Pfizer announced last week that its novel investigational combination antibiotic for multidrug-resistant bacterial infections has moved a step closer to regulatory approval in Europe.

In a press release, the company said the European Medicines Agency's Committee for Medicinal Products for Human Use (CHMP) recommended the granting of marketing authorization for Emblaveo (aztreonam-avibactam) for treating adults with complicated intra-abdominal infections, hospital-acquired pneumonia (including ventilator-associated pneumonia), complicated urinary tract infections (including pyelonephritis), and infections caused by aerobic gram-negative organisms with limited treatment options.

An option for nearly untreatable infections

Jointly developed by Pfizer and Abbvie, Emblaveo combines an old beta-lactam antibiotic (aztreonam) with a newer beta-lactamase inhibitor (avibactam). The combination aims to restore aztreonam's activity against gram-negative bacteria that carry two defense mechanisms—metallo-beta-lactamase (MBL) enzymes and other beta-lactamase enzymes—that confer resistance to nearly all currently available antibiotics.

While aztreonam can evade degradation by MBLs on its own, the addition of avibactam helps restore its activity against other beta-lactamases.

"Gram-negative bacteria are often resistant to multiple drugs, leaving infected patients very ill and at high risk of severe complications, including mortality," said James Rusnak, MD, PhD, Pfizer's senior vice president and chief development officer for internal medicine, anti-infectives and hospital. "If approved, Emblaveo could offer hope to adult patients with life-threatening Gram-negative bacterial infections that currently have limited treatment options."

The European Commission will review the CHMP recommendation and is expected to decide whether to grant central marketing authorizations in the European Union in the coming months.

If approved, Emblaveo could offer hope to adult patients with life-threatening Gram-negative bacterial infections that currently have limited treatment options.

An observational study of patients in Finland and the Netherlands suggests gut microbiota composition may be linked to risk of hospitalization for infection.

In the study, which was released last week in advance of the upcoming European Congress of Clinical Microbiology and Infectious Diseases, a team led by researchers at Amsterdam University Medical Center sequenced the DNA of fecal samples from 10,699 participants (4,248 from the Netherlands and 6,451 from Finland). Their aim was to measure the microbiota composition, diversity, and relative abundance of butyrate-producing bacteria—which are commonly depleted in patients hospitalized for severe infections—and examine associations with infection risk using computer modeling. Pre-clinical models have indicated butyrate-producing bacteria may have a protective effect against systemic infections.

Over 5 to 7 years of follow-up, 602 study participants were hospitalized with or died from infections, mainly community-acquired pneumonia, and the researchers found that their gut microbiota composition differed from those who were not hospitalized. Specifically, each 10% increase in abundance of butyrate-producing bacteria was associated with a 25% reduced risk of hospitalization in the Dutch participants and 14% lower risk in the Finnish cohort. These associations remained unchanged after adjustment for demographics, lifestyle, antibiotic exposure, and comorbidities.

"Gut microbiome composition, specifically colonisation with butyrate-producing bacteria, is associated with protection against hospitalisation for infectious diseases in the general population across two independent European cohorts," the study authors wrote. "Further studies should investigate whether modulation of the microbiome can reduce the risk of severe infections."

A Mayo Clinic–led study shows that colorectal cancer surgeries dropped 17.3% in the first 9 months of the COVID-19 pandemic and that more patients were diagnosed as having later-stage disease.

The study, published yesterday in the Journal of the American College of Surgeons, used the National Cancer Database to compare rates of surgeries for colorectal cancer, tumor stages, socioeconomic factors, and other variables among 105,317 patients before and during the pandemic (2019 and 2020).

Colorectal cancer, the third most common cancer in the United States, is being increasingly diagnosed in younger adults, the researchers noted.

10,000 fewer patients had surgery

Surgeries for rectal and colon cancer declined 21% and 16%, respectively, in 2020, corresponding to an overall 17.3% drop. Patients also had a significantly lower rate of early-stage cancer (35.5% vs 38.2%) and a significantly higher rate of advanced tumors (19.2% vs 15.7%), but treatment delays weren't noted after diagnosis. The advanced-cancer burden was greater in Black, uninsured or Medicaid-insured, and lower-income patients.

"We found that approximately 10,000 fewer patients did not have surgery for colorectal cancer in 2020 compared to 2019," senior author David Larson, MD, MBA, of Mayo Clinic, said in an American College of Surgeons news release. "That's a profound decrease."

There may be multiple reasons for the decline, such as screening delays, fear of COVID-19 exposure that deterred some patients from seeking care, and disparities in cancer care that likely worsened during the pandemic, the authors said.