Patient outcomes by baseline pathogen resistance phenotype and genotype in CERTAIN-1, a Phase 3 study of cefepime-taniborbactam versus meropenem in adults with complicated urinary tract infection.

CERTAIN-1 was a Phase 3, double-blind, randomized, parallel group study of the efficacy and safety of cefepime-taniborbactam versus meropenem in the treatment of adults with complicated urinary tract infection (cUTI), including acute pyelonephritis. We determined susceptibility of Enterobacterales and Pseudomonas aeruginosa baseline pathogens to cefepime-taniborbactam and comparators and characterized ß-lactam resistance mechanisms. Microbiologic response and clinical response were assessed in patient subsets defined by baseline pathogens that were of cefepime-, multidrug-, or carbapenem-resistant phenotype or that carried ß-lactamase genes. Among Enterobacterales baseline pathogens, 26.8%, 4.1%, and 3.0% carried genes for extended-spectrum ß-lactamases (ESBLs), AmpC, and carbapenemases, respectively. Within each treatment group, while composite success rates at Test of Cure in resistant subsets by pathogen species were similar to those by pathogen overall, composite success rates in meropenem patients were numerically lower for cefepime-resistant Escherichia coli (9/19; 47.4%) and ESBL E. coli (13/25; 52.0%) compared with E. coli overall (62/100; 62.0%). Cefepime-taniborbactam achieved composite success in 7/8 (87.5%) patients with carbapenem-resistant Enterobacterales and 8/9 (88.9%) patients with Enterobacterales with a carbapenemase gene (5 OXA-48-group; 2 KPC-3; 2 NDM-1). Cefepime-taniborbactam also achieved composite success in 8/16 (50.0%) patients and clinical success in 13/16 (81.3%) patients with P. aeruginosa; corresponding rates were 4/7 (57.1%) and 6/7 (85.7%) for meropenem. Cefepime-taniborbactam demonstrated efficacy in adult cUTI patients with cefepime-, multidrug-, and carbapenem-resistant pathogens including pathogens with ESBL, AmpC, and carbapenemase genes. CLINICAL TRIALS: This study is registered with ClinicalTrials.gov as NCT03840148.

Cefepime-Taniborbactam in Complicated Urinary Tract Infection.

BACKGROUND: Carbapenem-resistant Enterobacterales species and multidrug-resistant Pseudomonas aeruginosa are global health threats. Cefepime-taniborbactam is an investigational ß-lactam and ß-lactamase inhibitor combination with activity against Enterobacterales species and P. aeruginosa expressing serine and metallo-ß-lactamases. METHODS: In this phase 3, double-blind, randomized trial, we assigned hospitalized adults with complicated urinary tract infection (UTI), including acute pyelonephritis, in a 2:1 ratio to receive intravenous cefepime-taniborbactam (2.5 g) or meropenem (1 g) every 8 hours for 7 days; this duration could be extended up to 14 days in case of bacteremia. The primary outcome was both microbiologic and clinical success (composite success) on trial days 19 to 23 in the microbiologic intention-to-treat (microITT) population (patients who had a qualifying gram-negative pathogen against which both study drugs were active). A prespecified superiority analysis of the primary outcome was performed after confirmation of noninferiority. RESULTS: Of the 661 patients who underwent randomization, 436 (66.0%) were included in the microITT population. The mean age of the patients was 56.2 years, and 38.1% were 65 years of age or older. In the microITT population, 57.8% of the patients had complicated UTI, 42.2% had acute pyelonephritis, and 13.1% had bacteremia. Composite success occurred in 207 of 293 patients (70.6%) in the cefepime-taniborbactam group and in 83 of 143 patients (58.0%) in the meropenem group. Cefepime-taniborbactam was superior to meropenem regarding the primary outcome (treatment difference, 12.6 percentage points; 95% confidence interval, 3.1 to 22.2; P = 0.009). Differences in treatment response were sustained at late follow-up (trial days 28 to 35), when cefepime-taniborbactam had higher composite success and clinical success. Adverse events occurred in 35.5% and 29.0% of patients in the cefepime-taniborbactam group and the meropenem group, respectively, with headache, diarrhea, constipation, hypertension, and nausea the most frequently reported; the frequency of serious adverse events was similar in the two groups. CONCLUSIONS: Cefepime-taniborbactam was superior to meropenem for the treatment of complicated UTI that included acute pyelonephritis, with a safety profile similar to that of meropenem. (Funded by Venatorx Pharmaceuticals and others; CERTAIN-1 ClinicalTrials.gov number, NCT03840148.).

Efficacy and Safety of Omadacycline Versus Linezolid in Acute Bacterial Skin and Skin Structure Infections in Persons Who Inject Drugs.

INTRODUCTION: Acute bacterial skin and skin structure infections (ABSSSI) represent one of the most common reasons for emergency department visits, and are frequent complications of intravenous drug use in persons who inject drugs (PWID). This study examined the efficacy and safety of omadacycline, versus linezolid, in PWID and persons who do not inject drugs, in the Phase 3 Omadacycline in Acute Skin and Skin Structure Infection (OASIS-1, OASIS-2) studies. METHODS: Eligible participants were aged ≥ 18 years with qualifying skin infections: wound infection, cellulitis, erysipelas, or major abscess. The primary efficacy endpoint was early clinical response (ECR) in the modified intent-to-treat (mITT) population, defined as survival with ≥ 20% reduction in lesion size at 48-72 h after the first dose of omadacycline or linezolid. Key secondary endpoints included investigator-assessed clinical response at the post-treatment evaluation (PTE) in the mITT and clinical per-protocol populations, and clinical response at PTE in the micro-mITT population. Safety was assessed based on adverse events (AEs) and standard clinical laboratory tests. Efficacy endpoints of clinical response at ECR and PTE were analyzed for the mITT and clinically evaluable (CE) PTE populations. RESULTS: In total, 1380 patients (822 PWID, 558 non-PWID) were included in this secondary analysis. Wound infections were reported more frequently in the PWID subgroup (72.8%) at baseline; cellulitis or erysipelas (43.9%) and major abscess (37.4%) were the most frequently reported baseline infections in the non-PWID subgroup. Clinical success rates at ECR and PTE in the mITT population, and at PTE in the CE population, were high for patients receiving omadacycline or linezolid. Severe or serious treatment-emergent AEs (TEAEs), and TEAEs leading to discontinuation, were infrequent. CONCLUSION: This subgroup analysis showed that omadacycline was effective and well tolerated, regardless of PWID status.

Clinical Efficacy of Patients With Secondary Bacteremia Treated With Omadacycline: Results From Phase 3 Acute Bacterial Skin and Skin Structure Infections and Community-Acquired Bacterial Pneumonia Studies.

In this post hoc analysis of the 63 patients with secondary bacteremia enrolled in the 3 omadacycline phase 3 studies of acute bacterial skin/skin structure infections (ABSSSI) and community-acquired bacterial pneumonia (CABP), we determined that omadacycline is a viable therapeutic option for appropriate patients with secondary bacteremia.

Efficacy of Omadacycline Versus Moxifloxacin in the Treatment of Community-Acquired Bacterial Pneumonia by Disease Severity: Results From the OPTIC Study.

BACKGROUND: Severity/mortality risk scores and disease characteristics may assist in deciding whether patients with community-acquired bacterial pneumonia (CABP) require outpatient treatment or hospitalization. The phase 3 OPTIC (Omadacycline for Pneumonia Treatment In the Community) study enrolled patients with Pneumonia Outcomes Research Team (PORT) risk class II-IV. Omadacycline demonstrated noninferiority to moxifloxacin in adults with CABP, at early clinical response (ECR) and posttreatment evaluation (PTE). We assessed efficacy of omadacycline versus moxifloxacin in these patients based on disease severity. METHODS: Patients were randomized 1:1 to receive intravenous (IV) omadacycline (100 mg every 12 hours for 2 doses followed by 100 mg daily [q24h], with optional transition to omadacycline 300 mg orally q24h after 3 days of IV treatment) or moxifloxacin IV 400 mg q24h (with optional transition to 400 mg orally q24h after 3 days of IV treatment). Total treatment duration was 7-14 days. We compared rates of early clinical success (72-120 hours after first dose) and investigator-assessed clinical success at PTE (5-10 days after last dose) in subgroups based (1) on severity/mortality risk scores (PORT, CURB-65, systemic inflammatory response syndrome, quick Sequential [Sepsis-related] Organ Failure Assessment, modified ATS, SMART-COP) and (2) on presence of baseline radiographic characteristics, chronic obstructive pulmonary disease (COPD)/asthma, or bacteremia. RESULTS: Altogether, 774 patients (omadacycline, n = 386; moxifloxacin, n = 388) were randomized. Clinical success rates (ECR/PTE) were similar between treatment groups (across all subgroups). Efficacy across treatment groups was similar in patients with baseline radiographic characteristics or COPD/asthma, but moxifloxacin had higher clinical success rates in patients with bacteremia. CONCLUSIONS: Efficacy of omadacycline was similar to that of moxifloxacin, regardless of disease severity/mortality risk and disease characteristics.

Safety and efficacy of omadacycline by body mass index in patients with community-acquired bacterial pneumonia: Subanalysis from a randomized controlled trial.

OBJECTIVES: To examine the safety and efficacy of omadacycline by body mass index (BMI) in adults with community-acquired bacterial pneumonia (CABP) from a Phase III trial. METHODS: Patients hospitalized for suspected CABP were randomized 1:1 to receive intravenous omadacycline or moxifloxacin, with an optional transition to oral, for a total of 7-14 days. Early clinical response (ECR) was assessed 72-120 h after receipt of the first dose, and clinical success was assessed 5-10 days after the last dose (post-treatment evaluation [PTE]). ECR was defined as improvement in at least two CABP symptoms with no worsening of other symptoms or use of rescue antibacterial treatment; success at PTE was defined as resolution of signs and symptoms to the extent that further antibacterial therapy was unnecessary. Safety evaluations included treatment-emergent adverse events and laboratory measures. Between-treatment comparisons were made by World Health Organization BMI categories and by diabetes history. RESULTS: Distribution of patients in the normal weight, overweight, and obese subgroups was fairly even. Clinical success for omadacycline-treated patients at ECR were similar across ascending BMI groups (OMC: 82.9%, 80.5%, 76.9%; MOX: 88.6%, 80.7%, 76.9%). Outcomes by diabetes status were generally similar in omadacycline- and moxifloxacin-treated patients. Patients who had clinical success or clinical stability at ECR generally showed continued clinical success at PTE. Safety profiles for omadacycline and moxifloxacin were largely similar across BMI subgroups and by diabetes history. CONCLUSION: The omadacycline fixed-dosing strategy showed consistent safety and efficacy in patients with CABP of different body sizes.

Omadacycline vs moxifloxacin in adults with community-acquired bacterial pneumonia.

OBJECTIVE: Community-acquired bacterial pneumonia (CABP) is a major clinical burden worldwide. In the phase III OPTIC study (NCT02531438) in CABP, omadacycline was found to be non-inferior to moxifloxacin for investigator-assessed clinical response (IACR) at post-treatment evaluation (PTE, 5-10 days after last dose). This article reports the efficacy findings, as specified in the European Medicines Agency (EMA) guidance. METHODS: Patients were randomized 1:1 to omadacycline 100 mg intravenously (every 12 h for two doses, then every 24 h) with optional transition to 300 mg orally after 3 days, or moxifloxacin 400 mg intravenously (every 24 h) with optional transition to 400 mg orally after 3 days. The total treatment duration was 7-14 days. The primary endpoint for EMA efficacy analysis was IACR at PTE in patients with Pneumonia Patient Outcomes Research Team (PORT) risk class III and IV. RESULTS: In total, 660 patients were randomized as PORT risk class III and IV. Omadacycline was non-inferior to moxifloxacin at PTE. The clinical success rates were 88.4% and 85.2%, respectively [intent-to-treat population; difference 3.3; 97.5% confidence interval (CI) -2.7 to 9.3], and 92.5% and 90.5%, respectively (clinically evaluable population; difference 2.0; 97.5% CI 3.2-7.4). Clinical success rates with omadacycline and moxifloxacin were similar against identified pathogens and across key subgroups. CONCLUSIONS: Omadacycline was non-inferior to moxifloxacin for IACR at PTE, with high clinical success across pathogen types and patient subgroups.

Safety and efficacy of omadacycline by BMI categories and diabetes history in two Phase III randomized studies of patients with acute bacterial skin and skin structure infections.

OBJECTIVES: The objectives of this post-hoc analysis were to examine the safety and efficacy of omadacycline by BMI categories and diabetes history in adults with acute bacterial skin and skin structure infections (ABSSSI) from two pivotal Phase III studies. PATIENTS AND METHODS: OASIS-1 (ClinicalTrials.gov identifier NCT02378480): patients were randomized 1:1 to IV omadacycline or linezolid for 7-14 days, with optional transition to oral medication. OASIS-2 (ClinicalTrials.gov identifier NCT02877927): patients received once-daily oral omadacycline or twice-daily oral linezolid for 7-14 days. Early clinical response (ECR) was defined as ≥20% reduction in lesion size 48-72 h after the first dose. Clinical success at post-treatment evaluation (PTE; 7-14 days after the last dose) was defined as symptom resolution such that antibacterial therapy was unnecessary. Safety was assessed by treatment-emergent adverse events and laboratory measures. Between-treatment comparisons were made with regard to WHO BMI categories and diabetes history. RESULTS: Patients were evenly distributed among healthy weight, overweight and obese groups. Clinical success for omadacycline-treated patients at ECR and PTE was similar across BMI categories. Outcomes by diabetes status were similar in omadacycline- and linezolid-treated patients: at ECR, clinical success rates were lower for those with diabetes; at PTE, clinical success was similar between treatment groups regardless of diabetes history. The safety of omadacycline and linezolid was largely similar across BMI groups and by diabetes history. CONCLUSIONS: Omadacycline efficacy in patients with higher BMI and in patients with diabetes was consistent with results from two pivotal Phase III ABSSSI trials. Fixed-dose omadacycline is an appropriate treatment for ABSSSI in adults regardless of BMI.

Safety and efficacy of omadacycline for treatment of community-acquired bacterial pneumonia and acute bacterial skin and skin structure infections in patients with mild-to-moderate renal impairment.

BACKGROUND: Many antibiotics require dosage adjustments in patients with renal impairment. In Phase III studies, omadacycline was non-inferior to moxifloxacin and linezolid in adults with community-acquired bacterial pneumonia (CABP) and acute bacterial skin and skin structure infections (ABSSSI), respectively. This analysis evaluated efficacy and safety measures from three omadacycline studies by patient renal function. METHODS: Patients were stratified as having normal renal function (creatinine clearance >89 mL/min), mild renal impairment (creatinine clearance 60-89 mL/min) or moderate renal impairment (creatinine clearance <60 mL/min); creatine clearance ≤30 mL/min (severe renal impairment) was an exclusion criterion. Efficacy endpoints were clinical success at the early clinical response (ECR) and post-treatment evaluation (PTE) time-points. Safety was evaluated as treatment-emergent adverse events (TEAEs) and laboratory measures. RESULTS: This subgroup analysis included 773 patients with CABP and 1339 patients with ABSSSI in intent-to-treat (ITT) and modified ITT populations, respectively. Clinical success rates were high at ECR and PTE across the studies (CABP 75-90%; ABSSSI 74-95%), and broadly similar between treatments, irrespective of renal function. Rates of TEAEs in patients with ABSSSI ranged from 33% to 52%, and were similar across renal function groups. In patients with CABP, higher rates were observed in patients with moderate renal impairment (56-61%) compared with patients with normal renal function or mild renal impairment (35-49%). The most common TEAEs were nausea and vomiting. CONCLUSIONS: Clinical success was similar across renal function groups, indicating no notable difference in the efficacy of omadacycline in patients with mild or moderate renal impairment. Omadacycline and comparators displayed similar safety profiles. CLINICALTRIALS. GOV REGISTRY: OPTIC (NCT02531438); OASIS-1 (NCT02378480); OASIS-2 (NCT02877927).

The Effect of Verapamil, a P-gp Inhibitor, on the Pharmacokinetics, Safety, and Tolerability of Omadacycline in Healthy Adults: A Phase I, Open-Label, Single-Sequence Study.

BACKGROUND: Omadacycline is a semisynthetic aminomethylcycline antibacterial derived from the tetracycline class. It is approved in the USA to treat adults with acute bacterial skin and skin-structure infections and community-acquired bacterial pneumonia. OBJECTIVES: This phase I, open-label study evaluated the effect of a potential drug-drug interaction of verapamil-a known P-glycoprotein (P-gp) inhibitor-with omadacycline on the pharmacokinetic profile of omadacycline in healthy adults. The safety and tolerability of omadacycline taken alone and in combination with verapamil were also evaluated. METHODS: A single oral dose of 240 mg verapamil extended release (ER) was given 2 h prior to a single oral dose of 300 mg omadacycline. RESULTS: Ten (83.3%) of the 12 participants enrolled in the study completed the study, and all enrolled participants were included in the safety and pharmacokinetic populations. An increase of 14-25% in systemic exposure to omadacycline was seen when administered following a single oral dose of 240 mg verapamil ER compared with omadacycline alone, as measured by the area under the concentration-time curve (AUC) from time 0 to 24 h after dosing (AUC0-24), from time 0 to the last quantifiable concentration (AUC0-t), from time 0 extrapolated to infinity (AUC0-inf), and by maximum (peak) observed plasma concentration (Cmax). Treatment-emergent adverse events were reported by one participant (nausea and headache). CONCLUSIONS: These findings suggest that, if given with a known P-gp inhibitor, dose adjustment of oral omadacycline is not warranted based on small increases in absorption and systemic exposure. No safety signals were identified.

Once-daily oral omadacycline versus twice-daily oral linezolid for acute bacterial skin and skin structure infections (OASIS-2): a phase 3, double-blind, multicentre, randomised, controlled, non-inferiority trial.

BACKGROUND: Pathogen resistance and safety concerns limit oral antibiotic options for the treatment of acute bacterial skin and skin structure infections (ABSSSI). We aimed to compare the efficacy and safety of once-daily oral omadacycline, an aminomethylcycline antibiotic, versus twice-daily oral linezolid for treatment of ABSSSI. METHODS: In this phase 3, double-blind, randomised, non-inferiority study, eligible adults with ABSSSI at 33 sites in the USA were randomly assigned (1:1) to receive omadacycline (450 mg orally every 24 h over the first 48 h then 300 mg orally every 24 h) or linezolid (600 mg orally every 12 h) for 7-14 days. Randomisation was done via an interactive response system using a computer-generated schedule, and stratified by type of infection (wound infection, cellulitis or erysipelas, or major abscess) and receipt (yes or no) of allowed previous antibacterial treatment. Investigators, funders, and patients were masked to treatment assignments. Primary endpoints were early clinical response, 48-72 h after first dose, in the modified intention-to-treat (mITT) population (randomised patients without solely Gram-negative ABSSSI pathogens at baseline), and investigator-assessed clinical response at post-treatment evaluation, 7-14 days after the last dose, in the mITT population and clinically evaluable population (ie, mITT patients who had a qualifying infection as per study-entry criteria, received study drug, did not receive a confounding antibiotic, and had an assessment of outcome during the protocol-defined window). The safety population included randomised patients who received any amount of study drug. We set a non-inferiority margin of 10%. This study is registered with ClinicalTrials.gov, NCT02877927, and is complete. FINDINGS: Between Aug 11, 2016, and June 6, 2017, 861 participants were assessed for eligibility. 735 participants were randomly assigned, of whom 368 received omadacycline and 367 received linezolid. Omadacycline (315 [88%] of 360) was non-inferior to linezolid (297 [83%] of 360) for early clinical response (percentage-point difference 5·0, 95% CI -0·2 to 10·3) in the mITT population. For investigator-assessed clinical response at post-treatment evaluation, omadacycline was non-inferior to linezolid in the mITT (303 [84%] of 360 vs 291 [81%] of 360; percentage-point difference 3·3, 95% CI -2·2 to 9·0) and clinically evaluable (278 [98%] of 284 vs 279 [96%] of 292; 2·3, -0·5 to 5·8) populations. Mild to moderate nausea and vomiting were the most frequent treatment-emergent adverse events in omadacycline (111 [30%] of 368 and 62 [17%] of 368, respectively) and linezolid (28 [8%] of 367 and 11 [3%] of 367, respectively) groups. INTERPRETATION: Once-daily oral omadacycline was non-inferior to twice-daily oral linezolid in adults with ABSSSI, and was safe and well tolerated. Oral-only omadacycline represents a new treatment option for ABSSSI, with potential for reduction in hospital admissions and cost savings. FUNDING: Paratek Pharmaceuticals.

An Integrated Safety Summary of Omadacycline, a Novel Aminomethylcycline Antibiotic.

Omadacycline is a semisynthetic tetracycline antibiotic. Phase III clinical trial results have shown that omadacycline has an acceptable safety profile in the treatment of acute bacterial skin and skin structure infections and community-acquired bacterial pneumonia. Similar to most tetracyclines, transient nausea and vomiting and low-magnitude increases in liver aminotransferases were the most frequent treatment-emergent adverse events in phase III studies but were not treatment limiting. Package insert warnings and precautions for omadacycline include tooth discoloration; enamel hypoplasia; inhibition of bone growth following use in late pregnancy, infancy, or childhood up to 8 years of age; an imbalance in mortality (2%, compared with 1% in moxifloxacin-treated patients) was observed in the phase III study in patients with community-acquired bacterial pneumonia. Omadacycline has no effect on the QT interval, and its affinity for muscarinic M2 receptors resulted in transient heart rate increases following dosing.

Early Clinical Response in Community-acquired Bacterial Pneumonia: From Clinical Endpoint to Clinical Practice.

BACKGROUND: Early clinical response (ECR) is a new endpoint to determine whether a drug should be approved for community-acquired bacterial pneumonia in the United States. The Omadacycline for Pneumonia Treatment In the Community (OPTIC) phase III study demonstrated noninferiority of omadacycline to moxifloxacin using this endpoint. This study describes the performance of the ECR endpoint and clinical stability relative to a posttreatment evaluation (PTE) of clinical success. METHODS: ECR was defined as symptom improvement 72-120 hours after the first dose of study drug (ECR window), no use of rescue antibiotics, and patient survival. Clinical success at PTE was an investigator assessment of success. Clinical stability was defined based on vital sign stabilization, described in the American Thoracic Society and Infectious Diseases Society of America community-acquired pneumonia treatment guidelines. RESULTS: During the ECR window, ECR was achieved in 81.1% and 82.7% of omadacycline and moxifloxacin patients, respectively. Similar numbers of patients achieved clinical stability in each treatment group (omadacycline 74.6%, moxifloxacin 77.6%). The proportion of patients with improved symptoms who were considered clinically stable increased across the ECR window (69.2-77.6% for omadacycline; 68.0-79.7% for moxifloxacin). There was high concordance (>70%) and high positive predictive value (>90%) of ECR and clinical stability with overall clinical success at PTE. CONCLUSIONS: Omadacycline was noninferior to moxifloxacin, based on a new ECR endpoint. Clinical stability was similarly high when measured in the same time frame as ECR. Both ECR and clinical stability showed high concordance and high positive predictive value with clinical success at PTE. CLINICAL TRIALS REGISTRATION: NCT02531438.

Omadacycline for Acute Bacterial Skin and Skin Structure Infections.

BACKGROUND: Within the last decade, methicillin-resistant Staphylococcus aureus (MRSA) has emerged as a frequent cause of purulent skin and soft tissue infections. New therapeutic options are being investigated for these infections. METHODS: We report an integrated analysis of 2 randomized, controlled studies involving omadacycline, a novel aminomethylcycline, and linezolid for the treatment of acute bacterial skin and skin structure infections (ABSSSI). Omadacycline in Acute Skin and Skin Structure Infections Study 1 (OASIS-1) initiated patients on intravenous omadacycline or linezolid, with the option to transition to an oral formulation after day 3. OASIS-2 was an oral-only study of omadacycline versus linezolid. RESULTS: In total, 691 patients received omadacycline and 689 patients received linezolid. Infection types included wound infection in 46.8% of patients, cellulitis/erysipelas in 30.5%, and major abscess in 22.7%. Pathogens were identified in 73.2% of patients. S. aureus was detected in 74.7% and MRSA in 32.4% of patients in whom a pathogen was identified. Omadacycline was noninferior to linezolid using the Food and Drug Administration primary endpoint of early clinical response (86.2% vs 83.9%; difference 2.3, 95% confidence interval -1.5 to 6.2) and using the European Medicines Agency primary endpoint of investigator-assessed clinical response at the posttreatment evaluation. Clinical responses were similar across different infection types and infections caused by different pathogens. Treatment-emergent adverse events, mostly described as mild or moderate, were reported by 51.1% of patients receiving omadacycline and 41.2% of those receiving linezolid. CONCLUSIONS: Omadacycline was effective and safe in ABSSSI. CLINICAL TRIALS REGISTRATION: NCT02378480 and NCT02877927.

Omadacycline for Community-Acquired Bacterial Pneumonia.

BACKGROUND: Omadacycline, a new once-daily aminomethylcycline antibiotic agent that can be administered intravenously or orally, reaches high concentrations in pulmonary tissues and is active against common pathogens that cause community-acquired bacterial pneumonia. METHODS: In a double-blind trial, we randomly assigned (in a 1:1 ratio) adults with community-acquired bacterial pneumonia (Pneumonia Severity Index risk class II, III, or IV) to receive omadacycline (100 mg intravenously every 12 hours for two doses, then 100 mg intravenously every 24 hours), or moxifloxacin (400 mg intravenously every 24 hours). A transition to oral omadacycline (300 mg every 24 hours) or moxifloxacin (400 mg every 24 hours), respectively, was allowed after 3 days; the total treatment duration was 7 to 14 days. The primary end point was early clinical response, defined as survival with improvement in at least two of four symptoms (cough, sputum production, pleuritic chest pain, and dyspnea) and no worsening of symptoms at 72 to 120 hours, without receipt of rescue antibacterial therapy. A secondary end point was investigator-assessed clinical response at a post-treatment evaluation 5 to 10 days after the last dose, with clinical response defined as resolution or improvement in signs or symptoms to the extent that further antibacterial therapy was unnecessary. A noninferiority margin of 10 percentage points was used. RESULTS: The intention-to-treat population included 386 patients in the omadacycline group and 388 patients in the moxifloxacin group. Omadacycline was noninferior to moxifloxacin for early clinical response (81.1% and 82.7%, respectively; difference, -1.6 percentage points; 95% confidence interval [CI], -7.1 to 3.8), and the rates of investigator-assessed clinical response at the post-treatment evaluation were 87.6% and 85.1%, respectively (difference, 2.5 percentage points; 95% CI, -2.4 to 7.4). Adverse events that emerged after treatment initiation were reported in 41.1% of the patients in the omadacycline group and 48.5% of the patients in the moxifloxacin group; the most frequent events were gastrointestinal (10.2% and 18.0%, respectively), and the largest difference was for diarrhea (1.0% and 8.0%). Twelve deaths (8 in the omadacycline group and 4 in the moxifloxacin group) occurred during the trial. CONCLUSIONS: Omadacycline was noninferior to moxifloxacin for the treatment of community-acquired bacterial pneumonia in adults. (Funded by Paratek Pharmaceuticals; OPTIC ClinicalTrials.gov number, NCT02531438 .).