Effect of tebipenem pivoxil hydrobromide on the normal gut microbiota of a healthy adult population in Sweden: a randomised controlled trial.

BACKGROUND: Antimicrobials cause perturbations in the composition and diversity of the host microbiome. We aimed to compare gut microbiome perturbations caused by oral tebipenem pivoxil hydrobromide (a novel carbapenem) and by amoxicillin-clavulanic acid (an orally administered ß-lactam-ß-lactam inhibitor combination widely used in clinical practice). METHODS: We did a phase 1, single-centre, randomised, parallel-group, active-control trial to evaluate the effect of tebipenem pivoxil hydrobromide on the human gut microbiota. Healthy participants aged 18 years or older with no documented illnesses during recruitment were enrolled at Karolinska University Hospital (Stockholm, Sweden). Study participants were stratified by sex and block-randomised in a 1:1 ratio to treatment with either tebipenem pivoxil hydrobromide (600 mg orally every 8 h) or amoxicillin-clavulanic acid (500 mg amoxicillin and 125 mg clavulanic acid orally every 8 h). The study included 10 days of treatment (days 1-10) and four follow-up visits (days 14, 21, 90, and 180). The trial was open-label for clinical investigators and patients, but masked for microbiology investigators. Faecal samples were collected at all visits. Sequencing of 16S rDNA was used to measure the diversity metrics, and quantitative culture to quantify selected taxa. The primary outcomes were changes in the α and ß diversity and log count of colony-forming units for selected taxa between samples compared with baseline (day 1), and whether any changes reverted during the follow-up period. The analyses were done in the intention-to-treat population. This study was registered with ClinicalTrials.gov (NCT04376554). FINDINGS: The study was conducted between Jan 23, 2020, and April 6, 2021. 49 volunteers were screened for eligibility, among whom 30 evaluable participants (14 men and 16 women) were assigned: 15 (50%) to the tebipenem pivoxil hydrobromide group and 15 (50%) to the amoxicillin-clavulanic acid group. Baseline characteristics were similar between groups. Complete follow-up was available for all participants, and all participants except one completed treatment as assigned. The diversity metrics showed significant changes from baseline during the treatment period. Significant decreases in richness were observed on days 4-10 (p≤0·0011) in the amoxicillin-clavulanic acid group and on days 4-14 (p≤0·0019) in the tebipenem pivoxil hydrobromide group. Similarly, evenness was significantly decreased during treatment in the amoxicillin-clavulanic acid group (day 4, p=0·030) and the tebipenem pivoxil hydrobromide group (days 4-10, p<0·0001) compared with baseline. Quantitative cultures showed significant decreases in Enterobacterales (days 4-7, p≤0·0030), Enterococcus spp (days 4-14, p=0·025 to p<0·0001), Bifidobacterium spp (days 2-4, p≤0·026), and Bacteroides spp (days 4-10, p≤0·030) in the tebipenem pivoxil hydrobromide group. Similarly, in amoxicillin-clavulanic acid recipients, significant changes were observed in Enterobacterales (days 4-10, p≤0·048), Bifidobacterium spp (days 2-4, p≤0·013), and Lactobacillus spp (days 2-4, p≤0·020). Samples from the follow-up period were not significantly different from those at baseline in ß diversity analysis (PERMANOVA, p>0·99). By the end of the study, no significant change was observed compared with baseline in either group. There were no deaths or severe adverse events. INTERPRETATION: The impact of tebipenem pivoxil hydrobromide on the gut microbiome was similar to that of amoxicillin-clavulanic acid. The safety of antibiotic use with regard to the microbiome should be given attention, as dysbiosis is associated with health and disease. FUNDING: Spero Therapeutics.

Impact of antibiotic pharmacokinetics in urine on recurrent bacteriuria following treatment of complicated urinary tract infections.

The clinical relevance of bacteriuria following antibiotic treatment of complicated urinary tract infections in clinical trials remains controversial. We evaluated the impact of urine pharmacokinetics on the timing of recurrent bacteriuria in a recently completed trial that compared oral tebipenem pivoxil hydrobromide to intravenous ertapenem. The urinary clearance and urine dwell time of ertapenem were prolonged relative to tebipenem and were associated with a temporal difference in the repopulation of bladder urine with bacteria following treatment, potentially confounding the assessment of efficacy.

Oral Tebipenem Pivoxil Hydrobromide in Complicated Urinary Tract Infection.

BACKGROUND: There is a need for oral antibiotic agents that are effective against multidrug-resistant gram-negative uropathogens. Tebipenem pivoxil hydrobromide is an orally bioavailable carbapenem with activity against uropathogenic Enterobacterales, including extended-spectrum beta-lactamase-producing and fluoroquinolone-resistant strains. METHODS: In this phase 3, international, double-blind, double-dummy trial, we evaluated the efficacy and safety of orally administered tebipenem pivoxil hydrobromide as compared with intravenous ertapenem in patients with complicated urinary tract infection or acute pyelonephritis. Patients were randomly assigned, in a 1:1 ratio, to receive oral tebipenem pivoxil hydrobromide (at a dose of 600 mg every 8 hours) or intravenous ertapenem (at a dose of 1 g every 24 hours) for 7 to 10 days (or up to 14 days in patients with bacteremia). The primary efficacy end point was overall response (a composite of clinical cure and favorable microbiologic response) at a test-of-cure visit (on day 19, within a ±2-day window) in the microbiologic intention-to-treat population. The noninferiority margin was 12.5%. RESULTS: A total of 1372 hospitalized adult patients were enrolled; 868 patients (63.3%) were included in the microbiologic intention-to-treat population (50.8% of whom had complicated urinary tract infections and 49.2% of whom had pyelonephritis). An overall response was seen in 264 of 449 patients (58.8%) who received tebipenem pivoxil hydrobromide, as compared with 258 of 419 patients (61.6%) who received ertapenem (weighted difference, -3.3 percentage points; 95% confidence interval [CI], -9.7 to 3.2). Clinical cure at the test-of-cure visit was observed in 93.1% of the patients in the microbiologic intention-to-treat population who received tebipenem pivoxil hydrobromide and 93.6% of patients who received ertapenem (weighted difference, -0.6 percentage point; 95% CI, -4.0 to 2.8); the majority of patients with microbiologic response failures at the test-of-cure visit were asymptomatic patients with recurrent bacteriuria. Secondary and subgroup analyses were supportive of the primary analysis. Adverse events were observed in 25.7% of patients who received tebipenem pivoxil hydrobromide and in 25.6% of patients who received ertapenem; the most common adverse events were mild diarrhea and headache. CONCLUSIONS: Oral tebipenem pivoxil hydrobromide was noninferior to intravenous ertapenem in the treatment of complicated urinary tract infection and acute pyelonephritis and had a similar safety profile. (Funded by Spero Therapeutics and the Department of Health and Human Services; ADAPT-PO ClinicalTrials.gov number, NCT03788967.).

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.

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.

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.

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.

Safety, Tolerability, Pharmacokinetics, and Drug Interaction Potential of SPR741, an Intravenous Potentiator, after Single and Multiple Ascending Doses and When Combined with ß-Lactam Antibiotics in Healthy Subjects.

SPR741 is a novel polymyxin B derivative, with minimal intrinsic antibacterial activity and reduced nonclinical nephrotoxicity compared to levels with polymyxin B, that interacts with the outer membrane of Gram-negative bacteria, enhancing penetration of coadministered antibiotics. The safety, tolerability, and pharmacokinetics (PK) of SPR741 were evaluated in two studies, after single and multiple intravenous (i.v.) doses in healthy adult subjects and after coadministration with partner antibiotics. In the single and multiple ascending-dose study, SPR741 or placebo was administered as a 1-h infusion at single doses of 5 to 800 mg and in multiple doses of 50 to 600 mg every 8 h (q8h) for 14 days. In the drug-drug interaction study, a single 400-mg i.v. dose of SPR741 was administered alone and in combination with piperacillin-tazobactam, ceftazidime, and aztreonam. PK parameters for SPR741 and partner antibiotics were determined using noncompartmental analysis. After single doses, a dose-linear and proportional increase in mean maximum concentration in plasma (Cmax) and area under the concentration-time curve (AUC) was observed. At doses of 100 to 800 mg, >50% of the dose was excreted in the urine in the first 4 h postdose. After multiple doses, the mean half-life was 2.2 h on day 1 and up to 14.0 h on day 14, with no evidence of accumulation after 14 days of dosing up to 400 mg. The PK profile of SPR741 and partner antibiotics was unchanged with coadministration. SPR741 was generally well tolerated at doses up to 1,800 mg/day. These data support further clinical development of SPR741 for treating serious infections due to resistant bacteria. (These studies have been registered at ClinicalTrials.gov under identifiers NCT03022175 and NCT03376529.).

Safety, Pharmacokinetics, and Food Effect of Tebipenem Pivoxil Hydrobromide after Single and Multiple Ascending Oral Doses in Healthy Adult Subjects.

Tebipenem pivoxil hydrobromide (TBPM-PI-HBr, formerly SPR994) is an orally available prodrug of tebipenem, a carbapenem with activity versus multidrug-resistant (MDR) Gram-negative pathogens, including quinolone-resistant and extended-spectrum-ß-lactamase-producing Enterobacteriaceae The safety and pharmacokinetics (PK) of tebipenem were studied after administration of single and multiple ascending oral doses of TBPM-PI-HBr in fed and fasted states. Healthy adults received single oral doses of TBPM-PI-HBr at 100 mg to 900 mg or placebo (n = 108) or multiple doses of 300 mg or 600 mg every 8 h or placebo (n = 16) for 14 days. In the single-ascending-dose (SAD) phase, mean tebipenem plasma concentrations increased in a linear and dose proportional manner for doses of 100 to 900 mg and were comparable in the fasted and fed states for the 300- and 600-mg doses. In the MAD phase, tebipenem maximum concentration (Cmax) was reached within 1.5 h and was dose proportional on day 1 and higher than dose proportional (2.7-fold) on day 14. AUC was more than 2-fold greater on day 1 (2.7-fold) and day 14 (2.5-fold) for 600 mg q8h than for 300 mg q8h. Approximately 55% to 60% of tebipenem was recovered in the urine. TBPM-PI-HBr was well tolerated; mild, transient diarrhea was the most commonly reported adverse event. TBPM-PI-HBr provides an orally bioavailable carbapenem option to treat serious infections caused by MDR Enterobacteriaceae and has the potential to decrease the need for intravenous antibiotic therapy in the hospital or outpatient setting. (This study has been registered at ClinicalTrials.gov under identifier NCT03395249.).

Fosfomycin for Injection (ZTI-01) Versus Piperacillin-tazobactam for the Treatment of Complicated Urinary Tract Infection Including Acute Pyelonephritis: ZEUS, A Phase 2/3 Randomized Trial.

BACKGROUND: ZTI-01 (fosfomycin for injection) is an epoxide antibiotic with a differentiated mechanism of action (MOA) inhibiting an early step in bacterial cell wall synthesis. ZTI-01 has broad in vitro spectrum of activity, including multidrug-resistant Gram-negative pathogens, and is being developed for treatment of complicated urinary tract infection (cUTI) and acute pyelonephritis (AP) in the United States. METHODS: Hospitalized adults with suspected or microbiologically confirmed cUTI/AP were randomized 1:1 to 6 g ZTI-01 q8h or 4.5 g intravenous (IV) piperacillin-tazobactam (PIP-TAZ) q8h for a fixed 7-day course (no oral switch); patients with concomitant bacteremia could receive up to 14 days. RESULTS: Of 465 randomized patients, 233 and 231 were treated with ZTI-01 and PIP-TAZ, respectively. In the microbiologic modified intent-to-treat (m-MITT) population, ZTI-01 met the primary objective of noninferiority compared with PIP-TAZ with overall success rates of 64.7% (119/184 patients) vs 54.5% (97/178 patients), respectively; treatment difference was 10.2% (95% confidence interval [CI]: -0.4, 20.8). Clinical cure rates at test of cure (TOC, day 19-21) were high and similar between treatments (90.8% [167/184] vs 91.6% [163/178], respectively). In post hoc analysis using unique pathogens typed by pulsed-field gel electrophoresis, overall success rates at TOC in m-MITT were 69.0% (127/184) for ZTI-01 versus 57.3% (102/178) for PIP-TAZ (difference 11.7% 95% CI: 1.3, 22.1). ZTI-01 was well tolerated. Most treatment-emergent adverse events, including hypokalemia and elevated serum aminotransferases, were mild and transient. CONCLUSIONS: ZTI-01 was effective for treatment of cUTI including AP and offers a new IV therapeutic option with a differentiated MOA for patients with serious Gram-negative infections. CLINICAL TRIAL REGISTRATION: NCT02753946.

Omadacycline for Acute Bacterial Skin and Skin-Structure Infections.

BACKGROUND: Acute bacterial skin and skin-structure infections are associated with substantial morbidity and health care costs. Omadacycline, an aminomethylcycline antibiotic that can be administered once daily either orally or intravenously, is active against pathogens that commonly cause such infections, including antibiotic-resistant strains. METHODS: In this double-blind trial, we randomly assigned adults with acute bacterial skin and skin-structure infections (in a 1:1 ratio) to receive omadacycline (100 mg given intravenously every 12 hours for two doses, then 100 mg given intravenously every 24 hours) or linezolid (600 mg given intravenously every 12 hours). A transition to oral omadacycline (300 mg every 24 hours) or oral linezolid (600 mg every 12 hours) was allowed after 3 days; the total treatment duration was 7 to 14 days. The primary end point was an early clinical response at 48 to 72 hours, defined as survival with a reduction in lesion size of at least 20% without rescue antibacterial therapy. A secondary end point was an investigator-assessed clinical response at the post-treatment evaluation 7 to 14 days after the last dose, with clinical response defined as survival with resolution or improvement in signs or symptoms of infection to the extent that further antibacterial therapy was unnecessary. For both end points, the noninferiority margin was 10 percentage points. RESULTS: In the modified intention-to-treat population, omadacycline (316 patients) was noninferior to linezolid (311 patients) with respect to early clinical response (rate of response, 84.8% and 85.5%, respectively; difference, -0.7 percentage points; 95% confidence interval [CI], -6.3 to 4.9). Omadacycline also was noninferior to linezolid with respect to investigator-assessed clinical response at the post-treatment evaluation in the modified intention-to-treat population (rate of response, 86.1% and 83.6%, respectively; difference, 2.5 percentage points; 95% CI, -3.2 to 8.2) and in the clinical per-protocol population (96.3% and 93.5%, respectively; difference, 2.8 percentage points; 95% CI, -1.0 to 6.9). In both groups, the efficacy of the trial drug was similar for methicillin-susceptible and methicillin-resistant Staphylococcus aureus infections. Adverse events were reported in 48.3% of the patients in the omadacycline group and in 45.7% of those in the linezolid group; the most frequent adverse events in both groups were gastrointestinal (in 18.0% and 15.8% of the patients in the respective groups). CONCLUSIONS: Omadacycline was noninferior to linezolid for the treatment of acute bacterial skin and skin-structure infections and had a similar safety profile. (Funded by Paratek Pharmaceuticals; OASIS-1 ClinicalTrials.gov number, NCT02378480 .).

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 .).

Macrolide therapy for community-acquired pneumonia due to atypical pathogens: outcome assessment at an early time point.

BACKGROUND: Therapy directed against atypical pathogens in patients with community-acquired pneumonia (CAP) is often recommended. This post-hoc analysis evaluated the effect of addition of a macrolide to ceftaroline fosamil or ceftriaxone treatment in atypical CAP. METHODS: Two phase 3, double-blind, comparative safety and efficacy studies of ceftaroline fosamil vs. ceftriaxone, FOCUS 1 and FOCUS 2, enrolled adults with CAP. Only FOCUS 1 included 24-h adjunctive clarithromycin therapy for all patients on day 1. Day 4 and test-of-cure (TOC) outcomes were compared for adjunctive vs. no adjunctive therapy. RESULTS: Of 1240 enrolled patients, 130 patients with CAP due to atypical pathogens alone were included (FOCUS 1, n = 64; FOCUS 2, n = 66). Among patients infected with Mycoplasma pneumoniae and/or Chlamydophila pneumoniae alone, a higher clinical response rate was observed with clarithromycin plus ceftaroline fosamil or ceftriaxone compared with treatment without additional clarithromycin at day 4 [38/49 (77.6%; FOCUS 1) vs. 24/43 (55.8%; FOCUS 2)], but not at the TOC assessment [42/49 (85.7%; FOCUS 1) vs. 41/43 (95.3%; FOCUS 2)]. In patients infected with Legionella pneumophila alone, a higher clinical response rate with adjunctive clarithromycin therapy was observed at the TOC assessment alone [12/12 (100%; FOCUS 1) vs. 14/19 (73.7%; FOCUS 2)]. The unadjusted odds ratio of a favourable clinical response at day 4 with adjunctive clarithromycin vs. no adjunctive clarithromycin was 2.4 (95% confidence interval 1.1-5.1; P = 0.0299) for all pathogens combined. CONCLUSIONS: These results suggest that empirical antibiotic therapy against atypical pathogens may improve early clinical response rate. This hypothesis is best evaluated in a prospective trial.

Single- and Multiple-Dose Study To Determine the Safety, Tolerability, Pharmacokinetics, and Food Effect of Oral MRX-I versus Linezolid in Healthy Adult Subjects.

A multipart phase 1 study was conducted to determine the safety, tolerability, pharmacokinetics, and food effect of the novel oral oxazolidinone, MRX-I, in healthy adults, as well as the tolerability of longer-term exposure of both oral MRX-I and linezolid. Thirty subjects in part 1 received single ascending doses of MRX-I or placebo under fasting or fed condition in a double-blind crossover design. Twelve subjects in part 2 received MRX-I at 800 mg every 12 h (q12h) for 14 days in a double-blind, placebo-controlled design. In part 3, 24 subjects were randomized to receive 28 days of MRX-I at 800 mg q12h or oral linezolid at 600 mg q12h for 28 days in a double-blind, double-dummy design. Oral MRX-I was associated with a greater bioavailability and exposure when administered with food, and minimal accumulation of MRX-I occurred after multiple-dose administration. Oral MRX-I was well tolerated at single doses of up to 1,200 and 800 mg q12h for up to 28 days; all adverse events were mild to moderate in severity, and there was no drug discontinuation due to adverse events. These data support further clinical development of oral MRX-I in the treatment of resistant Gram-positive bacterial infections.

Efficacy of ceftaroline fosamil for bacteremia associated with community-acquired bacterial pneumonia.

OBJECTIVES: Few publications of prospective studies have described patient outcomes in community-acquired bacterial pneumonia (CABP)-associated bacteremia. Our objective, in performing this subgroup analysis, was to assess outcomes in subjects with CABP-associated bacteremia in 2 randomized, double-blind clinical studies comparing treatment with ceftaroline fosamil versus ceftriaxone. METHODS: Our analysis summarizes baseline subject demographics, distribution of baseline pathogens isolated from blood cultures, clinical response rates at Day 4, and clinical cure rates at end of therapy and test of cure (8 to 15 days after end of therapy) in subjects with bacteremic CABP in the ceFtarOline Community-acquired pneUmonia trial vS ceftriaxone in hospitalized patients (FOCUS) studies. RESULTS: In the FOCUS studies, 23 of 614 patients in the ceftaroline fosamil-treated group and 22 of 614 patients in the ceftriaxone-treated group had CABP-associated bacteremia. Baseline demographics were similar between groups. Streptococcus pneumoniae was the most common baseline bloodstream isolate. For subjects with CABP-associated bacteremia, clinical response/cure rates were similar at Day 4 (60.9% vs 59.1%), end of therapy (69.6% vs 72.7%), and test of cure (69.6% vs 68.2%) for ceftaroline fosamil and ceftriaxone, respectively. CONCLUSIONS: In subjects with CABP-associated bacteremia, ceftaroline fosamil demonstrated similar clinical outcomes at Day 4, end of therapy, and test of cure compared with ceftriaxone.

Assessment of ceftaroline fosamil in the treatment of community-acquired bacterial pneumonia due to Streptococcus pneumoniae: insights from two randomized trials.

Ceftaroline fosamil resulted in higher cure rates than ceftriaxone in patients with community-acquired bacterial pneumonia in 2 randomized trials (FOCUS 1 and FOCUS 2). The present analysis examines the subgroup of patients with Streptococcus pneumoniae infection to determine whether the apparent difference in cure rates persists after adjusting for potential covariates. We retrospectively pooled subjects with S. pneumoniae isolated at baseline in the original studies and employed logistic regression to evaluate the independent relationship between clinical cure and treatment with ceftaroline. Covariates evaluated included demographics, severity of illness, bacteremia, and pathogen characteristics. The final cohort included 139 subjects (69 ceftaroline, 70 ceftriaxone). Unadjusted cure rates were 85.5% and 68.6% (P = 0.009) in the ceftaroline and ceftriaxone groups, respectively. After logistic regression, ceftaroline remained associated with higher cure rates. Our findings indicate that ceftaroline may result in improved outcomes of S. pneumoniae pneumonia. Formal clinical trials are warranted to confirm this hypothesis.

CANVAS 1 and 2: analysis of clinical response at day 3 in two phase 3 trials of ceftaroline fosamil versus vancomycin plus aztreonam in treatment of acute bacterial skin and skin structure infections.

Scientific and regulatory interest in assessing clinical endpoints after 48 to 72 h of treatment for acute bacterial skin and skin structure infections (ABSSSI) has increased. Historical, pre-antibiotic-era data suggest that a treatment effect relative to untreated controls can be discerned in this time interval. Ceftaroline fosamil, a broad-spectrum bactericidal cephalosporin with activity against Gram-positive organisms, including methicillin-resistant Staphylococcus aureus (MRSA), and Gram-negative organisms was efficacious in two phase 3 trials of complicated skin infections (CANVAS 1 and 2) using clinical cure rates at the test-of-cure visit. To assess an early clinical response in the CANVAS trials, a retrospective analysis using a day 3 clinical endpoint was conducted. Adults with ABSSSI received intravenous ceftaroline fosamil at 600 mg every 12 h (q12h) or vancomycin at 1 g plus aztreonam at 1 g (V/A) q12h for 5 to 14 days. Clinical response at day 3, defined as cessation of infection spread and absence of fever, was analyzed in patients with a lesion size of ≥ 75 cm(2) and either deep and/or extensive cellulitis, major abscess, or an infected wound. Day 3 integrated CANVAS clinical response rates were 74.0% (296/400) for ceftaroline and 66.2% (263/397) for V/A (difference, 7.8%; 95% confidence interval [CI], 1.3% to 14.0%). In the individual studies, absolute treatment differences of 9.4% (CANVAS 1) and 5.9% (CANVAS 2) favoring ceftaroline were observed. For ABSSSI due to MRSA, response rates were 81.7% and 77.4% in the ceftaroline and V/A groups, respectively. In this retrospective analysis, ceftaroline fosamil monotherapy had a numerically higher clinical response than V/A at day 3 in the treatment of ABSSSI.

FOCUS 2: a randomized, double-blinded, multicentre, Phase III trial of the efficacy and safety of ceftaroline fosamil versus ceftriaxone in community-acquired pneumonia.

OBJECTIVES: Ceftaroline (active form of the prodrug ceftaroline fosamil) is a novel cephalosporin with activity against pathogens commonly associated with community-acquired pneumonia (CAP), including Streptococcus pneumoniae and Gram-negative pathogens. This randomized, double-blind, Phase III study evaluated the efficacy and safety of ceftaroline fosamil in treating patients with CAP. The primary objective was to determine non-inferiority [lower limit of 95% confidence interval (CI) ≥ -10%] of clinical cure rates achieved with ceftaroline fosamil compared with those achieved with ceftriaxone in the clinically evaluable (CE) and modified intent-to-treat efficacy (MITTE) populations. METHODS: Patients hospitalized in a non-intensive care unit setting with CAP of Pneumonia Outcomes Research Team (PORT) risk class III or IV requiring intravenous (iv) therapy were randomized (1:1) to receive 600 mg of ceftaroline fosamil iv every 12 h or 1 g of ceftriaxone iv every 24 h. Clinical cure, microbiological response, adverse events (AEs) and laboratory tests were assessed. FOCUS 2 registration number NCT00509106 (http://clinicaltrials.gov/ct2/show/NCT00509106). RESULTS: The study enrolled 627 patients, 315 of whom received ceftaroline fosamil and 307 of whom received ceftriaxone. Patients in both treatment groups had comparable baseline characteristics. Clinical cure rates were as follows: CE population, 82.1% (193/235) for ceftaroline fosamil and 77.2% (166/215) for ceftriaxone [difference (95% CI), 4.9% (-2.5, 12.5)]; and MITTE population, 81.3% (235/289) for ceftaroline fosamil and 75.5% (206/273) for ceftriaxone [difference (95% CI), 5.9% (-1.0, 12.7)]. Clinical cure rates for CAP caused by S. pneumoniae in the microbiological MITTE (mMITTE) population were 83.3% (35/42) and 70.0% (28/40) for ceftaroline fosamil and ceftriaxone, respectively. Ceftaroline fosamil and ceftriaxone were well tolerated, with similar rates of AEs, serious AEs, deaths and discontinuations due to an AE. The most common AEs for ceftaroline fosamil-treated patients were diarrhoea, headache, hypokalaemia, insomnia and phlebitis, and the most common AEs for ceftriaxone-treated patients were diarrhoea, insomnia, phlebitis and hypertension. CONCLUSIONS: Ceftaroline fosamil achieved high clinical cure and microbiological response rates in patients hospitalized with CAP of PORT risk class III or IV. Ceftaroline fosamil was well tolerated, with a safety profile that is similar to that of ceftriaxone and other cephalosporins. Ceftaroline fosamil is a promising agent for the treatment of CAP.

Review of ceftaroline fosamil microbiology: integrated FOCUS studies.

Ceftaroline fosamil, the prodrug form of ceftaroline, is a novel broad-spectrum parenteral cephalosporin that exhibits antibacterial activity against typical respiratory pathogens such as Streptococcus pneumoniae, Haemophilus influenzae, Staphylococcus aureus and common Gram-negative pathogens. In particular, ceftaroline has activity against resistant Gram-positive cocci, including penicillin- and multidrug-resistant S. pneumoniae, as well as methicillin-resistant S. aureus. The activity of ceftaroline against these phenotypes is attributed to its ability to bind to modified penicillin-binding proteins with high affinity when compared with other ß-lactams. The activity of ceftaroline is not compromised by the ability of H. influenzae to produce ß-lactamase. Ceftaroline fosamil was compared with ceftriaxone for safety and efficacy in two randomized, double-blinded, controlled Phase III clinical trials for the treatment of community-acquired pneumonia (CAP). Microbiological assessments at baseline included respiratory specimen cultures, blood cultures, urinary antigen testing and atypical pathogen serology testing. By-subject and by-pathogen microbiological outcomes were assessed in the microbiologically evaluable population at the test-of-cure visit. The favourable microbiological response rates by subject for ceftaroline were 87.0% compared with 81.0% for ceftriaxone. The by-pathogen microbiological response rates of ceftaroline and ceftriaxone were 87.3% and 72.9% for S. pneumoniae, 83.3% and 85.0% for H. influenzae and 76.0% and 70.4% for S. aureus, respectively. Key baseline pathogens such as S. pneumoniae, H. influenzae and methicillin-susceptible S. aureus were susceptible to ceftaroline, with MIC(90)s of 0.03, 0.03 and 0.25 mg/L, respectively, supporting its utility as a promising new agent for treatment of CAP.