SOLITAIRE-IV: A Randomized, Double-Blind, Multicenter Study Comparing the Efficacy and Safety of Intravenous-to-Oral Solithromycin to Intravenous-to-Oral Moxifloxacin for Treatment of Community-Acquired Bacterial Pneumonia

Clin Infect Dis. 2016 Oct 15;63(8):1007-1016. doi: 10.1093/cid/ciw490. Epub 2016 Jul 22.


Background: Solithromycin, a novel macrolide antibiotic with both intravenous and oral formulations dosed once daily, has completed 2 global phase 3 trials for treatment of community-acquired bacterial pneumonia.

Methods: A total of 863 adults with community-acquired bacterial pneumonia (Pneumonia Outcomes Research Team [PORT] class II-IV) were randomized 1:1 to receive either intravenous-to-oral solithromycin or moxifloxacin for 7 once-daily doses. All patients received 400 mg intravenously on day 1 and were permitted to switch to oral dosing when clinically indicated. The primary objective was to demonstrate noninferiority (10% margin) of solithromycin to moxifloxacin in achievement of early clinical response (ECR) assessed 3 days after first dose in the intent-to-treat (ITT) population. Secondary endpoints included demonstrating noninferiority in ECR in the microbiological ITT population (micro-ITT) and determination of investigator-assessed success rates at the short-term follow-up (SFU) visit 5-10 days posttherapy.

Results: In the ITT population, 79.3% of solithromycin patients and 79.7% of moxifloxacin patients achieved ECR (treatment difference, -0.46; 95% confidence interval [CI], -6.1 to 5.2). In the micro-ITT population, 80.3% of solithromycin patients and 79.1% of moxifloxacin patients achieved ECR (treatment difference, 1.26; 95% CI, -8.1 to 10.6). In the ITT population, 84.6% of solithromycin patients and 88.6% of moxifloxacin patients achieved clinical success at SFU based on investigator assessment. Mostly mild/moderate infusion events led to higher incidence of adverse events overall in the solithromycin group. Other adverse events were comparable between treatment groups.

Conclusions: Intravenous-to-oral solithromycin was noninferior to intravenous-to-oral moxifloxacin. Solithromycin has potential to provide an intravenous and oral option for monotherapy for community-acquired bacterial pneumonia.

Clinical trials registration: NCT01968733.

Keywords: Streptococcus pneumoniae; clinical trial; community-acquired; pneumonia; solithromycin.

Publication types

  • Clinical Trial, Phase III
  • Multicenter Study
  • Randomized Controlled Trial

MeSH terms

  • Administration, Intravenous
  • Administration, Oral
  • Adult
  • Aged
  • Aged, 80 and over
  • Anti-Bacterial Agents / administration & dosage*
  • Anti-Bacterial Agents / adverse effects
  • Community-Acquired Infections / diagnosis
  • Community-Acquired Infections / drug therapy*
  • Community-Acquired Infections / microbiology*
  • Comorbidity
  • Drug Resistance, Bacterial
  • Female
  • Fluoroquinolones / administration & dosage*
  • Fluoroquinolones / adverse effects
  • Humans
  • Macrolides / administration & dosage*
  • Macrolides / adverse effects
  • Male
  • Microbial Sensitivity Tests
  • Middle Aged
  • Moxifloxacin
  • Pneumonia, Bacterial / diagnosis
  • Pneumonia, Bacterial / drug therapy*
  • Pneumonia, Bacterial / microbiology*
  • Treatment Outcome
  • Triazoles / administration & dosage*
  • Triazoles / adverse effects


  • Anti-Bacterial Agents
  • Fluoroquinolones
  • Macrolides
  • Triazoles
  • solithromycin
  • Moxifloxacin

Associated data