Developing Outcomes Assessments as Endpoints for Registrational Clinical Trials of Antibacterial Drugs: 2015 Update From the Biomarkers Consortium of the Foundation for the National Institutes of Health

In community-acquired pneumonia, adding oral clarithromycin to standard care increased early clinical response

SOURCE CITATION

Giamarellos-Bourboulis EJ, Siampanos A, Bolanou A, et al. Clarithromycin for early anti-inflammatory responses in community-acquired pneumonia in Greece (ACCESS): a randomised, double-blind, placebo-controlled trial. Lancet Respir Med. 2024;12:294-304. 38184008.

Clarithromycin for early anti-inflammatory responses in community-acquired pneumonia in Greece (ACCESS): a randomised, double-blind, placebo-controlled trial

BACKGROUND

Addition of macrolide antibiotics to β-lactam antibiotics for the treatment of patients in hospital with community-acquired pneumonia is based on results from observational studies and meta-analyses rather than randomised clinical trials. We investigated if addition of the macrolide clarithromycin to treatment with a β-lactam antibiotic in this population could improve early clinical response-the new regulatory endpoint for community-acquired pneumonia-and explored the possible contribution of modulation of the inflammatory host response to that outcome.

METHODS

The ACCESS trial was a phase 3 prospective, double-blind, randomised controlled trial, in which adults in hospital with community-acquired pneumonia who had systemic inflammatory response syndrome, Sequential Organ Failure Assessment (SOFA) score of 2 or more, and procalcitonin 0·25 ng/mL or more were enrolled in 18 internal medicine departments of public Greek hospitals. Patients were randomly assigned (1:1) by computer-generated block randomisation to standard of care medication (including intravenous administration of a third-generation cephalosporin or intravenous administration of β-lactam plus β-lactamase inhibitor combination) plus either oral placebo or oral clarithromycin 500 mg twice daily for 7 days. Investigators, staff, and patients were masked to group allocation. The primary composite endpoint required that patients fulfilled both of the following conditions after 72 hours (ie, day 4 of treatment): (1) decrease in respiratory symptom severity score of 50% or more as an indicator of early clinical response and (2) decrease in SOFA score of at least 30% or favourable procalcitonin kinetics (defined as ≥80% decrease from baseline or procalcitonin <0·25 ng/mL), or both, as an indicator of early inflammatory response. Participants who were randomly assigned and received allocated treatment were included in the primary analysis population. This trial is complete and is registered with the EU Clinical Trials Register (2020-004452-15) and ClinicalTrials.gov (NCT04724044).

FINDINGS

Patients were enrolled between Jan 25, 2021, and April 11, 2023, and 278 individuals were randomly allocated to receive standard of care in combination with either clarithromycin (n=139) or placebo (n=139). 134 patients in the clarithromycin group (five withdrew consent) and 133 patients in the placebo group (six withdrew consent) were included in the analysis of the primary endpoint. The primary endpoint was met in 91 (68%) patients in the clarithromycin group and 51 (38%) patients in the placebo group (difference 29·6% [95% CI 17·7-40·3]; odds ratio [OR] 3·40 [95% CI 2·06-5·63]; p<0·0001). Serious treatment-emergent adverse events (TEAEs) occurred in 58 (43%) patients in the clarithromycin group and 70 (53%) patients in the placebo group (difference 9·4% [95% CI -2·6 to 20·9]; OR 0·67 [95% CI 0·42 to 1·11]; p=0·14). None of the serious TEAEs was judged to be related to treatment assignment.

INTERPRETATION

Addition of clarithromycin to standard of care enhances early clinical response and attenuates the inflammatory burden of community-acquired pneumonia. The mechanism of benefit is associated with changes in the immune response. These findings suggest the importance of adding clarithromycin to β-lactams for treatment of patients in hospital with community-acquired pneumonia to achieve early clinical response and early decrease of the inflammatory burden.

FUNDING

Hellenic Institute for the Study of Sepsis and Abbott Products Operations.

Clinical evaluation of the BioFire Respiratory Pathogen Panel for the guidance of empirical antimicrobial therapy in critically ill patients with hospital-acquired pneumonia: A multicenter, quality improvement project

BACKGROUND

We aimed to determine whether implementing antimicrobial stewardship based on multiplex bacterial PCR examination of respiratory fluid can enhance outcomes of critically ill patients with hospital-acquired pneumonia (HAP).

METHODS

We conducted a quality improvement study in two hospitals in France. Adult patients requiring invasive mechanical ventilation with a diagnosis of HAP were included. In the pre-intervention period (August 2019 to April 2020), antimicrobial therapy followed European guidelines. In the «intervention» phase (June 2020 to October 2021), treatment followed a multiplex PCR-guided protocol. The primary endpoint was a composite endpoint made of mortality on day 28, clinical cure between days 7 and 10, and duration of invasive mechanical ventilation on day 28. The primary outcome was analyzed with a DOOR strategy.

RESULTS

A total of 443 patients were included in 3 ICUs from 2 hospitals (220 pre-intervention; 223 intervention). No difference in the ranking of the primary composite outcome was found (DOOR: 50.3%; 95%CI, 49.9%-50.8%). The number of invasive mechanical ventilation-free days at day 28 was 10.0 [0.0; 19.0] in the baseline period and 9.0 [0.0; 20.0] days during the intervention period (p = 0.95). The time-to-efficient antimicrobial treatment was 0.43 ± 1.29 days before versus 0.55 ± 1.13 days after the intervention (p = 0.56).

CONCLUSION

Implementation of Rapid Multiplex PCR to guide empirical antimicrobial therapy for critically ill patients with HAP was not associated with better outcomes. However, adherence to stewardship was low, and the study may have had limited power to detect a clinically important difference.

Moving Beyond Mortality: Development and Application of a Desirability of Outcome Ranking (DOOR) Endpoint for Hospital-Acquired Bacterial Pneumonia and Ventilator-Associated Bacterial Pneumonia

BACKGROUND

Hospital-acquired and ventilator-associated bacterial pneumonia (HABP/VABP) are frequently caused by multidrug-resistant organisms. Patient-centered endpoints in clinical trials are needed to develop new antibiotics for HABP/VABP. Desirability of outcome ranking (DOOR) is a paradigm for the design, analysis, and interpretation of clinical trials based on a patient-centered, benefit-risk evaluation.

METHODS

A multidisciplinary committee created an infectious diseases DOOR endpoint customized for HABP/VABP, incorporating infectious complications, serious adverse events, and mortality. We applied this to 2 previously completed, large randomized controlled trials for HABP/VABP. ZEPHyR compared vancomycin to linezolid and VITAL compared linezolid to tedizolid. For each trial, we evaluated the DOOR distribution and probability, including DOOR component and partial credit analyses. We also applied DOOR in subgroup analyses.

RESULTS

In both trials, the HABP/VABP DOOR demonstrated similar overall clinical outcomes between treatment groups. In ZEPHyR, the probability that a participant treated with linezolid would have a more desirable outcome than a participant treated with vancomycin was 50.2% (95% confidence interval [CI], 45.1%--55.3%). In VITAL, the probability that a participant treated with tedizolid would have a more desirable outcome than a participant treated with linezolid was 48.7% (95% CI, 44.8%-52.6%). The DOOR component analysis revealed that participants treated with tedizolid had a less desirable outcome than those treated with linezolid when considering clinical response alone. However, participants with decreased renal function had improved overall outcomes with tedizolid.

CONCLUSIONS

The HABP/VABP DOOR provided more granular information about clinical outcomes than is typically presented in clinical trials. HABP/VABP trials would benefit from prospectively using DOOR.

Changes in the prevalence of pathogens causing hospital-acquired bacterial pneumonia and the impact of their antimicrobial resistance patterns on clinical outcomes: A propensity-score-matched study

BACKGROUND

This study aimed to evaluate changes in the prevalence of pathogens causing hospital-acquired bacterial pneumonia (HABP) and their antimicrobial resistance patterns in recent years, and to identify risk factors for 28-day all-cause mortality (ACM) in patients with HABP.

METHODS

A propensity-score-matched study was performed by randomly allocating patients with ventilator-associated and non-ventilator-associated bacterial pneumonia admitted to two university hospitals between 2011 and 2021.

RESULTS

In total, 17,250 patients with HABP were enrolled. The annual incidence of Staphylococcus aureus HABP decreased during the study period, while that of Klebsiella pneumoniae HABP increased significantly each year. Over the same period, the resistance rate of S. aureus to methicillin decreased from 88.4% to 64.4%, while the non-susceptibility rate of K. pneumoniae to carbapenems increased from 0% to 38%. HABP caused by A. baumannii [adjusted odds ratio (aOR) 1.50, 95% confidence interval (CI) 1.25-1.79], K. pneumoniae (aOR 1.28, 95% CI 1.16-1.40) and Stenotrophomonas maltophilia (aOR 1.32, 95% CI 1.05-1.66) was a risk factor for 28-day ACM. Patients with HABP caused by methicillin-resistant S. aureus and carbapenem-non-susceptible A. baumannii or K. pneumoniae had a significantly lower probability of survival. HABP with preceding coronavirus disease 2019 (COVID-19) was associated with high 28-day ACM (aOR 5.40, 955 CI 3.03-9.64) and high incidence of bacteraemic pneumonia (aOR 40.55, 95% CI 5.26-312.79).

CONCLUSIONS

This study showed shifting trends in HABP-causing pathogens in terms of annual incidence and resistance rates to major therapeutic antimicrobial agents. HABP-causing bacterial pathogens, their antimicrobial resistance phenotypes, and preceding COVID-19 were significantly associated with progression of HABP to bloodstream infection and 28-day ACM in infected patients.

Improving Traditional Registrational Trial End Points: Development and Application of a Desirability of Outcome Ranking End Point for Complicated Urinary Tract Infection Clinical Trials

BACKGROUND

Traditional end points used in registrational randomized, controlled trials (RCTs) often do not allow for complete interpretation of the full range of potential clinical outcomes. Desirability of outcome ranking (DOOR) is an approach to the design and analysis of clinical trials that incorporates benefits and risks of novel treatment strategies and provides a global assessment of patient experience.

METHODS

Through a multidisciplinary committee of experts in infectious diseases, clinical trial design, drug regulation, and patient experience, we developed a DOOR end point for infectious disease syndromes and demonstrated how this could be applied to 3 registrational drug trials (ZEUS, APEKS-cUTI, and DORI-05) for complicated urinary tract infections (cUTIs). ZEUS compared fosfomycin to piperacillin/tazobactam, APEKS-cUTI compared cefiderocol to imipenem, and DORI-05 compared doripenem to levofloxacin. Using DOOR, we estimated the probability of a more desirable outcome with each investigational antibacterial drug.

RESULTS

In each RCT, the DOOR distribution was similar and the probability that a patient in the investigational arm would have a more desirable outcome than a patient in the control arm had a 95% confidence interval containing 50%, indicating no significant difference between treatment arms. DOOR facilitated improved understanding of potential trade-offs between clinical efficacy and safety. Partial credit and subgroup analyses also highlight unique attributes of DOOR.

CONCLUSIONS

DOOR can effectively be used in registrational cUTI trials. The DOOR end point presented here can be adapted for other infectious disease syndromes and prospectively incorporated into future clinical trials.

Trends in Hospital-Acquired and Ventilator-Associated Bacterial Pneumonia Trials

BACKGROUND

New drug development for hospital-acquired bacterial pneumonia (HABP) and ventilator-associated bacterial pneumonia (VABP) is critical. Challenges remain in the conduct of HABP/VABP trials, especially in the contexts of enrollment, endpoints, nonstudy antibacterial drug therapy, and antimicrobial resistance.

METHODS

Four Phase 3 noninferiority trials (n = 2433 participants) submitted to the Food and Drug Administration after 2015 were analyzed for enrollment statistics, participant characteristics associated with 28-day all-cause mortality (ACM), microbiology, and receipt of nonstudy antibacterial drugs. All trials primarily enrolled patients with gram-negative bacterial infections.

RESULTS

The mean trial length was 2.7 years and the mean recruitment rate was 0.17 participants/site/month. ACM at 28 days was 17.1% and was higher among participants diagnosed with ventilated HABP (31.9%) or VABP (19.0%) than nonventilated HABP (9.9%). VABP participants tended to be younger, less likely to have chronic obstructive pulmonary disease, and more likely to have previously sustained an injury. Age, South American residence, diagnosis of ventilated HABP or VABP, and Acinetobacter baumannii infection were all associated with 28-day ACM in a multivariate logistic regression model. Infection by A. baumannii was most common in Eastern European and Asia/Pacific participants, and Eastern European isolates exhibited the highest levels of meropenem resistance. Concomitant nonstudy antibacterial drug therapy most commonly included beta-lactams and was initiated earliest in Western Europe.

CONCLUSION

This analysis of recent trials may assist in trial considerations for HABP/VABP development programs and promote needed antibacterial drug development for patients with serious infections.

A Phase 3, Randomized, Investigator-blinded Trial Comparing Ceftobiprole With a Standard-of-care Cephalosporin, With or Without Vancomycin, for the Treatment of Pneumonia in Pediatric Patients

BACKGROUND

The advanced-generation, broad-spectrum, intravenous (IV) cephalosporin, ceftobiprole, is an effective and well-tolerated treatment for adults with hospital-acquired pneumonia (HAP) or community-acquired pneumonia (CAP), but its effects in pediatric patients have not been established.

METHODS

In this multicenter, investigator-blinded, active-controlled, phase 3 study, patients 3 months to <18 years old with HAP or CAP requiring hospitalization were randomized (2:1) to ceftobiprole versus standard-of-care (SoC) IV cephalosporin treatments (ceftazidime or ceftriaxone), with or without vancomycin. After at least 3 days' IV treatment, patients demonstrating clinical improvement could be switched to an oral antibiotic, to complete a minimum of 7 days' treatment.

RESULTS

Overall, 138 patients were randomized to ceftobiprole (n = 94) or a SoC cephalosporin (n = 44). Median time to oral switch was 6.0 days in the ceftobiprole group and 8.0 days in the SoC cephalosporin group. While on IV therapy, adverse events and treatment-related adverse events were reported by 20.2% and 8.5% of ceftobiprole-treated patients and 18.2% and 0% of SoC cephalosporin-treated patients. Early clinical response rates at day 4 in the intention-to-treat population were 95.7% and 93.2% (between-group difference, 2.6%; 95% confidence interval, -5.5% to 14.7%) in the ceftobiprole and comparator groups, and clinical cure rates at the test-of-cure visit were 90.4% and 97.7% (between-group difference, -7.3%; 95% confidence interval, -15.7% to 3.6%), respectively.

CONCLUSIONS

Ceftobiprole was well tolerated and, in this small phase 3 study, demonstrated similar efficacy to SoC cephalosporins in pediatric patients with HAP or CAP requiring hospitalization.

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.

Health-Related Quality of Life as Measured by the 12-Item Short-Form Survey Among Adults With Community-Acquired Bacterial Pneumonia who Received Either Lefamulin or Moxifloxacin in 2 Phase III Randomized, Double-Blind, Double-Dummy Clinical Trials

Background

Interest in patient-reported outcomes (PROs) as part of benefit–risk assessment for new drug approvals is increasing. Lefamulin is the first intravenous (IV) and oral pleuromutilin antibiotic for treatment of adults with community-acquired bacterial pneumonia (CABP). Assessment of health-related quality of life (HRQoL) was prospectively incorporated in its CABP trials (Lefamulin Evaluation Against Pneumonia [LEAP] 1 and 2) via the 12-Item Short-Form Survey (SF-12), a widely used PRO that measures general health status in 8 domains.

Methods

HRQoL was evaluated by SF-12 at baseline and test of cure (TOC; 5–10 days after the last study drug dose) in patients who received lefamulin or moxifloxacin in LEAP 1 (IV/oral treatment) and LEAP 2 (oral-only treatment). SF-12 outcomes included the 8 domains, physical component and mental component summary scores, and the Short-Form Six-Dimension health utility score.

Results

Analysis included 1215 patients (lefamulin: n = 607; moxifloxacin: n = 608). At baseline, all mean SF-12 scores in both treatment groups were well below the United States reference mean. Clinically meaningful and significant improvements from baseline to TOC were observed in all SF-12 scores. No significant differences in mean score improvements from baseline to TOC between treatment groups were observed. SF-12 score improvements at TOC across predefined subgroups were comparable between treatment groups.

Conclusions

Results indicate that adults with CABP experienced comparable HRQoL improvements with lefamulin relative to moxifloxacin, and treatment with either agent resulted in returns to population norm HRQoL levels. These data suggest that lefamulin is a potential alternative to moxifloxacin for treatment of adults with CABP.

Achieving Regulatory Alignment for Anti-Infective Clinical Trials

The growing concern of antimicrobial resistance coupled with the dearth of new antibacterial agents in development is a major public health threat. Multiple stakeholder efforts are underway to address the various challenges facing this field; while some progress has been made, antibacterial drug development continues to be a challenging area. The economic issues encountered in this space are probably today the most cogent; however, there are many other aspects that continue to pose challenges to enterprises engaging in this area, from the difficulties in discovering and advancing new classes of products to scientific issues with clinical trial design and feasibility in conducting these trials.

The Foundation for the National Institutes of Health Biomarkers Consortium: Past Accomplishments and New Strategic Direction

The Foundation for the National Institutes of Health (FNIH) Biomarkers Consortium (BC) is a public–private partnership that aims to facilitate drug development with biomarkers across a range of therapeutic areas. The BC is organized to address specific precompetitive biomarker projects, giving participating stakeholders a role in the design and conduct of projects and making the results freely public. Ultimately, the goals of the BC are to accelerate the development of new medicines, inform regulatory decision making, and improve patient care. Here, we describe how the BC works and briefly highlight its accomplishments. The BC has had many notable successful biomarker projects in the past 12 years, including I‐SPY2, which has improved clinical trials and biomarker use for breast cancer, and an evidentiary framework for biomarker qualification. Recently, the BC has undergone a strategic expansion of its scope to include related drug development tools along the lines of the Biomarkers, Endpoints, and other Tools (BEST) resource.

Evidence-Based Study Design for Hospital-Acquired Bacterial Pneumonia and Ventilator-Associated Bacterial Pneumonia

BACKGROUND

The US Food and Drug Administration solicited evidence-based recommendations to improve guidance for studies of hospital-acquired bacterial pneumonia (HABP) and ventilator-associated bacterial pneumonia (VABP).

METHODS

We analyzed 7 HABP/VABP datasets to explore novel noninferiority study endpoints and designs, focusing on alternatives to all-cause mortality (ACM).

RESULTS

ACM at day 28 differed for ventilated HABP (27.8%), VABP (18.0%), and nonventilated HABP (14.5%). A "mortality-plus" (ACM+) composite endpoint was constructed by combining ACM with patient-relevant, infection-related adverse events from the Medical Dictionary for Regulatory Activities toxic/septic shock standardized query. The ACM+ rate was 3-10 percentage points above that of ACM across the studies and treatment groups. Predictors of higher ACM/ACM+ rates included older age and elevated acute physiology and chronic health evaluation (APACHE) II score. Only patients in the nonventilated HABP group were able to report pneumonia symptom changes.

CONCLUSIONS

If disease groups and patient characteristics in future studies produce an ACM rate so low (<10%-15%) that a fixed noninferiority margin of 10% cannot be justified (requiring an odds ratio analysis), an ACM+ endpoint could lower sample size. Enrichment of studies with patients with a higher severity of illness would increase ACM. Data on symptom resolution in nonventilated HABP support development of a patient-reported outcome instrument.

The early change of SOFA score as a prognostic marker of 28-day sepsis mortality: analysis through a derivation and a validation cohort

Background

Since the Sepsis-3 criteria, change in Sequential Organ Failure Assessment (SOFA) score has become a key component of sepsis identification. Thus, it could be argued that reversal of this change (Δ_SOFA) may reflect sepsis response and could be used as measure of efficacy in interventional trials. We aimed to assess the predictive performance of Δ_SOFA for 28-day mortality.

Methods

Data from two previously published randomized controlled trials were studied: the first reporting on patients with severe Gram-negative infections as a derivation cohort and the second reporting on patients with ventilator-associated pneumonia as a validation cohort. Only patients with sepsis according to the Sepsis-3 definition were included in this analysis. SOFA scores were calculated on days 1, 2, 3, 5, 7, 14, and 28.

Results

We included 448 patients within the derivation cohort and 199 within the validation cohort. Mean SOFA scores on day 1 were 6.06 ± 4.07 and 7.84 ± 3.39, and 28 day mortality 22.8% and 29.6%, respectively. In the derivation cohort, the earliest time point where Δ_SOFA score predicted mortality was day 7 (AUROC (95% CI) 0.84 (0.80–0.89); p < 0.001). The best tradeoff for prediction was found with 25% changes (78% sensitivity, 80% specificity); less than 25% decrease of admission SOFA was associated with increased mortality (odds ratio for death 14.87). This finding was confirmed in the validation cohort.

Conclusions

Δ_SOFA on day 7 is a useful early prognostic marker of 28-day mortality and could serve as an endpoint in future sepsis trials alongside mortality.

Trial registration

ClinicalTrials.gov numbers NCT01223690 and NCT00297674

Patient-reported outcome measurement in community-acquired pneumonia: feasibility of routine application in an elderly hospitalized population

Background

Community-acquired pneumonia (CAP) is a leading cause of morbidity and mortality worldwide, but few studies have evaluated the feasibility of routine patient-reported outcome measures (PROMs) in this illness. This study investigates the feasibility and limitations of three credible PROM instruments in a representative hospitalized cohort to identify potential barriers to routine application.

Methods

A sample of multimorbid hospitalized subjects meeting a standardized CAP definition was recruited. Demographic and clinical data of those able and unable to participate in PROM assessment were compared. The EQ-5D-5L, CAP-Sym 18 Questionnaire, and Late-Life Function and Disability Instrument (LLFDI) were administered (via face-to-face interview) at admission and discharge and (via phone interview or mail) at 30 and 90 days post-discharge. Feasibility measures included the proportion of individuals able to participate in assessment, attrition rates, data completeness, and instrument completion times. Scores at admission and 30 days post-discharge were examined for association with age.

Results

Of 82 subjects screened, 44 (54%) participated. Cognitive impairment (n = 12, 15%) commonly precluded participation. Seventeen (39%) participants were lost to follow-up by 90 days. Missing data at item level was negligible for all instruments, regardless of the mode of completion. Completion of the three instruments collectively in a face-to-face interview took a median of 17 min (IQ range 13-21) per participant. The burden of reported symptoms at admission was higher for younger participants aged 18-74 years (mean (standard deviation)) CAP-Sym 18 score at admission 34.2 (18.6) vs. 19.0 (11.3) for those aged ≥ 75 years.

Conclusions

Routine application of PROMs can provide valuable information relating to multiple aspects of clinical recovery for individuals hospitalized with CAP. However, heterogeneous demographic characteristics and complex underlying health status introduce challenges to feasibility and interpretability of these instruments in this population.

Trial registration

ClinicalTrials.gov, NCT02835040.

Omadacycline: A Modernized Tetracycline

When tetracyclines were introduced in the 1940s, these antibiotics offered a broad spectrum of activity against multiple types of pathogens. However, their utility waned after the selection of tetracycline resistance in the pathogens against which they were effective. Omadacycline is a semisynthetic aminomethylcycline antibacterial derived from the tetracycline class of antibiotics that is unaffected by these resistance mechanisms. It has an appropriate spectrum of activity for community-acquired infections, including those caused by many resistant organisms. Omadacycline offers a well-tolerated treatment for acute bacterial skin and skin structure infections and community-acquired bacterial pneumonia. Omadacycline has minimal known drug-drug interactions, and should be administered in a fasting state, avoiding dairy and cation-containing products for at least 4 hours after dosing. It does not require dose adjustments for sex, age, or hepatic or renal impairment, and has a safety profile similar to that of other oral tetracyclines. Because omadacycline can be administered effectively orally, it can help reduce hospitalization costs associated with intravenous antibiotic administration. This special supplement to Clinical Infectious Diseases offers an in-depth examination of omadacycline development, including discussions of pharmacokinetic and pharmacodynamic trials, spectrum of activity and preclinical data, early clinical trials, phase III clinical trials, and an integrated safety summary.

Patient-reported outcome measures in community-acquired pneumonia: a systematic review of application and content validity

Introduction

Patient-reported outcome measures (PROMs) are a vital component of patient-centred care. Community-acquired pneumonia (CAP) is a significant contributor to morbidity, mortality and health service costs globally, but there is a lack of consensus regarding PROMs for this condition.

Methods

We searched MEDLINE, EMBASE and Cochrane Collaboration for studies, both interventional and observational, of adult recovery from CAP that applied at least one validated PROM instrument and were published before 31 December 2017. The full text of included studies was examined and data collected on study design, PROM instruments applied, constructs examined and the demographic characteristics of the populations measured. For all CAP-specific PROM instruments identified, content validity was assessed using the COnsensus based Standards for selection of health Measurement INstruments guidelines (COSMIN).

Results

Forty-two articles met the inclusion criteria and applied a total of 17 different PROM instruments including five (30%) classified as CAP specific, six (35%) as generic and six (35%) that measured functional performance or were specific to another disease. The 36-Item Short Form Survey (SF-36) was the most commonly used instrument (15 articles). Only one of 11 (9%) patient cohorts assessed using a CAP-specific instrument had a mean age ≥70 years. The CAP-Sym and CAP-BIQ questionnaires had sufficient content validity, though the quality of evidence for all CAP-specific instruments was rated as very low to low.

Discussion

PROM instruments used to measure recovery from CAP are inconsistent in constructs measured and have frequently been developed and validated in highly selective patient samples that are not fully representative of the hospitalised CAP population. The overall content validity of all available CAP-specific instruments is unclear, particularly in the context of elderly hospitalised populations. Based on current evidence, generic health instruments are likely to be of greater value for measuring recovery from CAP in this group.

Early improvement in severely ill patients with pneumonia treated with ceftobiprole: a retrospective analysis of two major trials

BACKGROUND

Patients with pneumonia who are elderly or severely ill are at a particularly high risk of mortality. This post hoc retrospective analysis of data from two Phase III studies evaluated early improvement outcomes in subgroups of high-risk patients with community-acquired pneumonia (CAP) and hospital-acquired pneumonia (HAP, excluding ventilator-associated pneumonia [VAP]).

METHODS

One study included hospitalised CAP patients randomised to ceftobiprole or ceftriaxone ± linezolid treatment. The other study included HAP patients, who were randomised to ceftobiprole or ceftazidime plus linezolid treatment. The primary outcome was rate of early clinical response (Day 3 in CAP and Day 4 in HAP patients). Additional outcome measures included clinical cure at a test-of-cure visit, 30-day all-cause mortality and safety.

RESULTS

The overall high-risk group comprised 398 CAP patients and 307 HAP patients with risk factors present at baseline. The rate of early response was numerically higher in ceftobiprole-treated patients vs comparator-treated patients in the following high-risk groups: CAP patients aged ≥75 years (16.3% difference, 95% confidence interval [CI]: 1.8, 30.8); CAP patients with COPD (20.1% difference, 95% CI: 8.8, 31.1); all high-risk HAP patients (12.5% difference, 95% CI: 3.5, 21.4); HAP patients with >10 baseline comorbidities (15.3% difference, 95% CI: 0.3, 30.4).

CONCLUSIONS

Previous studies show that ceftobiprole is an efficacious therapy for patients with pneumonia who are at high risk of poor outcomes. This post hoc analysis provides preliminary evidence that ceftobiprole treatment may have advantages over other antibiotics in terms of achieving early improvement in high-risk patients with HAP (excluding VAP) and in some subgroups of high-risk CAP patients.

TRIAL REGISTRATION

NCT00210964 : registered September 21, 2005; NCT00229008 : registered September 29, 2005; NCT00326287 : registered May 16, 2006.

Which outcomes are reported in cellulitis trials? Results of a review of outcomes included in cellulitis trials and a patient priority setting survey

BACKGROUND

There is an emerging need to develop consistent outcomes in clinical trials to allow effective comparison of treatment effects. No systematic review has previously looked at the reporting of outcome measures used in randomized controlled trials (RCTs) on the treatment and prevention of cellulitis (erysipelas).

OBJECTIVES

The primary aim of this review was to describe the breadth of outcomes reported from RCTs on cellulitis treatment and prevention. The secondary aim was to identify outcome themes from patients' and healthcare professionals' feedback from a cellulitis Priority Setting Partnership (PSP).

METHODS

We conducted a review of all outcome measures used in RCTs from two recent Cochrane reviews. Free-text responses from a cellulitis priority setting survey were used to understand the perspectives of patients and healthcare professionals.

RESULTS

Outcomes from 42 RCTs on treatment of cellulitis and six RCTs on prevention of cellulitis were reviewed. Only 28 trials stated their primary outcome. For trials assessing treatment of cellulitis, clinical response to treatment was categorized in 25 different ways. Five of these trials used an outcome that was in accordance with FDA guidance and only four trials incorporated either quality of life or patient satisfaction. For trials assessing prevention of cellulitis, recurrence was the key outcome measure. From the cellulitis PSP, prevention of recurrence, clinical features and long-term disease impact were the most important outcome themes for patients.

CONCLUSIONS

We have shown that in cellulitis treatment and prevention research, there is significant heterogeneity in clinical outcomes, inadequate focus on patient-reported outcomes, and a disparity between what is currently measured and what patients and healthcare professionals feel is important. We recommend that future cellulitis treatment trials consider the use of longer-term outcomes to capture recurrence and long-term morbidity, as well as short-term resolution of acute infection.

Efficient Delivery of Investigational Antibacterial Agents via Sustainable Clinical Trial Networks

The economics of antibiotics can be improved by infectious diseases–specific clinical trial networks. While developers would still need to implement an independent phase 1 program as well as studies focused on highly resistant pathogens, standardized procedures in a network focused on usual drug resistance phenotype isolates would permit sharing of controls and would predictably generate high-quality pivotal data for product registration while creating cost and time savings in the range of 30%–40%. This would reduce economic barriers to antibiotic development and contribute to public health.

Patient-Reported Outcome Assessments as Endpoints in Studies in Infectious Diseases

The goal of administering medical interventions is to help patients live longer or live better. In keeping with this goal, there has been increasing interest in taking the "voice" of the patient into account during the development process, specifically in the evaluation of treatment benefits of medical interventions, and use of patient-centered outcome data to justify reimbursement. Patient-reported outcomes (PROs) are outcome assessments (OAs) used to define endpoints that can provide direct evidence of treatment benefit on how patients feel or function. When PROs are appropriately developed, they can increase the efficiency and clinical relevance of clinical trials. Several PROs have been developed for OA in specific infectious diseases indications, and more are under development. PROs also hold promise for use in evaluating adherence, adverse effects, satisfaction with care, and routine clinical practice.

Advancing New Antibacterial Drug Development for Treatment of Hospital-Acquired and Ventilator-Associated Bacterial Pneumonia

The Clinical Trials Transformation Initiative (CTTI), a public-private partnership comprised of representatives from academia, the pharmaceutical industry, and the federal government including the US Food and Drug Administration, formed a group working toward a common goal of intensified research to facilitate the development of new antibacterial drug therapies for treatment of hospital-acquired and ventilator-associated bacterial pneumonia (HABP/VABP). The summary of the CTTI HABP/VABP project in this supplement of Clinical Infectious Diseases is a first step in this direction.

Progress in the Fight Against Multidrug-Resistant Bacteria 2005-2016: Modern Noninferiority Trial Designs Enable Antibiotic Development in Advance of Epidemic Bacterial Resistance

From a public health perspective, new antibacterial agents should be evaluated and approved for use before widespread resistance to existing agents emerges. However, for multidrug-resistant pathogens, demonstration of superior efficacy of a new agent over a current standard-of-care agent is routinely feasible only when epidemic spread of these dangerous organisms has already occurred. One solution to enable proactive drug development is to evaluate new antibiotics with improved in vitro activity against MDR pathogens using recently updated guidelines for active control, noninferiority trials of selected severe infections caused by more susceptible pathogens. Such trials are feasible because they enroll patients with infections due to pathogens with a "usual drug resistance" phenotype that will be responsive to widely registered standard-of-care comparator antibiotics. Such anticipatory drug development has constructively reshaped the antibiotic pipeline and offers the best chance of making safe and efficacious antibiotics available to the public ahead of epidemic resistance.

The time-dependent "cure-death" model investigating two equally important endpoints simultaneously in trials treating high-risk patients with resistant pathogens

A variety of primary endpoints are used in clinical trials treating patients with severe infectious diseases, and existing guidelines do not provide a consistent recommendation. We propose to study simultaneously two primary endpoints, cure and death, in a comprehensive multistate cure-death model as starting point for a treatment comparison. This technique enables us to study the temporal dynamic of the patient-relevant probability to be cured and alive. We describe and compare traditional and innovative methods suitable for a treatment comparison based on this model. Traditional analyses using risk differences focus on one prespecified timepoint only. A restricted logrank-based test of treatment effect is sensitive to ordered categories of responses and integrates information on duration of response. The pseudo-value regression provides a direct regression model for examination of treatment effect via difference in transition probabilities. Applied to a topical real data example and simulation scenarios, we demonstrate advantages and limitations and provide an insight into how these methods can handle different kinds of treatment imbalances. The cure-death model provides a suitable framework to gain a better understanding of how a new treatment influences the time-dynamic cure and death process. This might help the future planning of randomised clinical trials, sample size calculations, and data analyses.

Clinician-Reported Outcome Assessments of Treatment Benefit: Report of the ISPOR Clinical Outcome Assessment Emerging Good Practices Task Force

A clinician-reported outcome (ClinRO) assessment is a type of clinical outcome assessment (COA). ClinRO assessments, like all COAs (patient-reported, observer-reported, or performance outcome assessments), are used to 1) measure patients' health status and 2) define end points that can be interpreted as treatment benefits of medical interventions on how patients feel, function, or survive in clinical trials. Like other COAs, ClinRO assessments can be influenced by human choices, judgment, or motivation. A ClinRO assessment is conducted and reported by a trained health care professional and requires specialized professional training to evaluate the patient's health status. This is the second of two reports by the ISPOR Clinical Outcomes Assessment-Emerging Good Practices for Outcomes Research Task Force. The first report provided an overview of COAs including definitions important for an understanding of COA measurement practices. This report focuses specifically on issues related to ClinRO assessments. In this report, we define three types of ClinRO assessments (readings, ratings, and clinician global assessments) and describe emerging good measurement practices in their development and evaluation. The good measurement practices include 1) defining the context of use; 2) identifying the concept of interest measured; 3) defining the intended treatment benefit on how patients feel, function, or survive reflected by the ClinRO assessment and evaluating the relationship between that intended treatment benefit and the concept of interest; 4) documenting content validity; 5) evaluating other measurement properties once content validity is established (including intra- and inter-rater reliability); 6) defining study objectives and end point(s) objectives, and defining study end points and placing study end points within the hierarchy of end points; 7) establishing interpretability in trial results; and 8) evaluating operational considerations for the implementation of ClinRO assessments used as end points in clinical trials. Applying good measurement practices to ClinRO assessment development and evaluation will lead to more efficient and accurate measurement of treatment effects. This is important beyond regulatory approval in that it provides evidence for the uptake of new interventions into clinical practice and provides justification to payers for reimbursement on the basis of the clearly demonstrated added value of the new intervention.

Regulatory Incentives for Antibiotic Drug Development: A Review of Recent Proposals

Two primary regulatory mechanisms have been proposed to incentivize new antibiotic development: (1) changing Food and Drug Administration (FDA) approval processes to expedite antibiotic approval; and (2) offering enhanced possibilities for market exclusivity. Changes to the FDA regulatory approval process include greater reliance on surrogate endpoints such as biomarkers, use of noninferiority hypothesis designs for key preapproval clinical trials, and development of an expedited development track specific for antibiotics called the Limited Population pathway. The second strategy intended to encourage new antibiotic development has been to provide additional market exclusivity incentives based on regulatory approval. While these pathways have some positive attributes, they also present enhanced risks to patients associated with lower regulatory barriers and the market exclusivity incentives may not efficiently direct resources to the true origins of antibiotic innovation.