Antibiotic prescriptions in the context of suspected bacterial respiratory tract superinfections in the COVID-19 era: a retrospective quantitative analysis of antibiotic consumption and identification of antibiotic prescription drivers

This study aims to quantify antibiotic consumption for suspected respiratory tract superinfections in COVID-19 patients, while investigating the associated drivers of antibiotic prescribing in light of the current signs of antibiotic overuse. Adult patients with a positive COVID-19 diagnosis admitted to a Belgian 721-bed university hospital were analyzed retrospectively (March 11th-May 4th, 2020), excluding short-term admissions (< 24 h). Antibiotic prescriptions were analyzed and quantified, using Defined Daily Doses (DDD) per admission and per 100 bed days. Possible drivers of antibiotic prescribing were identified by means of mixed effects logistic modelling analysis with backwards selection. Of all included admissions (n = 429), 39% (n = 171) were prescribed antibiotics for (presumed) respiratory tract superinfection (3.6 DDD/admission; 31.5 DDD/100 bed days). Consumption of beta-lactamase inhibitor-penicillin combinations was the highest (2.55 DDD/admission; 23.3 DDD/100 bed days). Four drivers were identified: fever on admission (OR 2.97; 95% CI 1.42-6.22), lower SpO₂/FiO₂ ratio on admission (OR 0.96; 95% CI 0.92-0.99), underlying pulmonary disease (OR 3.04; 95% CI 1.12-8.27) and longer hospital stay (OR 1.09; 95% CI 1.03-1.16). We present detailed quantitative antibiotic data for presumed respiratory tract superinfections in hospitalized COVID-19 patients. In addition to knowledge on antibiotic consumption, we hope antimicrobial stewardship programs will be able to use the drivers identified in this study to optimize their interventions in COVID-19 wards.

Troponin T in COVID-19 hospitalized patients: kinetics matter

Background

Coronavirus disease 2019 (COVID-19) pandemic continues to overwhelm healthcare systems worldwide, due to high numbers of critical cases over a short period of time (1,2). Elevated cardiac troponin (cTn), suggestive for myocardial damage, was associated with increased mortality of COVID-19 patients (3,4). However, data addressing the role of cTn in major adverse cardiovascular events (MACE) in COVID-19 patients is scarce.

Objectives

We aimed to assess the role of baseline cTnT and cTnT kinetics in the prediction of MACE and in - hospital mortality in COVID-19 patients. Furthermore, we assessed the association between cTnT kinetics and the need of cardiac imaging evaluation.

Methods

310 patients were included prospectively (age 64.6±16.7 years, 180 (58.1%) males), between March 2020 and April 2020. Clinical data including demographics,medical history,comorbidities,clinical evaluation,laboratory exams,in-hospital treatment,complications and outcomes were collected at admission and during hospitalization by physicians in charge. Two hundred and two patients (65.1%) with at least two cTnT values assessed during hospitalization, at 24–48 hours interval were included in the final analysis. cTnT-values >0.011 micrograms/L were considered elevated, according to hospital laboratory cut-offs. Patients were divided into 3 groups according to cTnT kinetics profile: 1 – variable, 2 – descending and 3 – constant. cTnT slope was defined as the ratio of the cTnT change and the change in time. MACE were considered as the primary endpoint and were composed by all-cause mortality, acute heart failure, acute coronary syndrome, pericarditis, myocarditis, atrial fibrillation or flutter and pulmonary embolism. In-hospital mortality was considered as the secondary endpoint.

Results

Mean hospitalization was 13.9±0.9 days. MACE occurred in 60 patients (29.7%) and in-hospital mortality in 40 (19.8%) patients. Baseline cTnT independently predicted MACE, (p=0.047, HR 1.805, 95% CI 1.009–3.231) and in-hospital mortality (p=0.009, HR 2.322, 95% CI 1.234–4.369) (Figure 1A, 1B). An increased cTnT slope independently predicted in-hospital mortality (p=0.041, HR 1.006, 95% CI 1.000–1.011). Constant cTnT was associated with lower MACE and mortality rates (p=0,000, HR 3.080, 95% CI, 1.914–4.954, p=0.000, HR 2.851. 95% CI 1.828–4.447, respectively) (Figure 1C, 1D, 2). Cardiac imaging evaluation was performed in 8 (16%) patients with constant cTnT, 30 (60%) with variable cTnT, and 12 (24%) with descending cTnT.(p<0.001)

Conclusions

Increased baseline cTnT independently predicted MACE and in-hospital mortality in COVID-19 patients. The magnitude of cTnT increase over time was associated with in-hospital mortality. On the contrary, patients with constant cTnT had lower MACE and in-hospital mortality rates. These finding emphasize the additional role of cTnT testing in COVID-19 patients for risk stratification and improved diagnostic pathway and management

Funding Acknowledgement

Type of funding sources: None.

Combination of gemcitabine and cetuximab in patients with advanced cholangiocarcinoma: A phase II study of the Belgian Group of Digestive Oncology

245

Background: Cholangiocarcinomas (CCK) are uncommon tumors with an increasing incidence and a poor prognosis. Epidermal growth factor receptor (EGFR) expression and activation in CCK have been demonstrated.

Methods: We conducted a multicenter phase II trial combining cetuximab (Ctx), an anti-EGFR chimerized IgG1 monoclonal antibody, to gemcitabine (Gem). Patients with either locally advanced (LA) or metastatic (M) CCK (excluding gallbladder) were included; no prior systemic therapy was allowed. Ctx was administrated at the initial dose of 400 mg/m2 and further injections at 250 mg/m2 every 7 days, and Gem was administrated at 1000 mg/m2 on days 1, 8, and 15 every 4 weeks. The primary endpoint was the progression-free survival (PFS) rate at 6 months. A Simon 2-stage design was used. We hypothesized that Gem/Ctx would improve 6 month-PFS rate from 20% to 40%. We needed 3 patients with PFS ≥ 6 months from the first 13 to further include a total of 43 patients.

Results: Forty-four patients with advanced CCK (41% LA/59%M) were enrolled from 09/2008 to 01/2010. Median age was 61.5 years (range 40-86) and baseline ECOG PS was 0 for 68% and 1 for 32% of the patients. Forty-three percent of the patients had prior surgery. Forty-six percent of the patients were free from progression at 6 months. Median PFS was 5.8 months (95% CI, 4.4-7.4 m) and median overall survival was 11.6 months (95% CI, 8.7-14.6 m). Nine patients (20.9%) had partial response with a median duration of 5 months (range 2-10 m). Disease control rate (PR + SD > 8 weeks) was 81.4%. The most common grades 3/4 related-toxicities were haematological abnormalities (47.7%), skin rash (13.6%) and fatigue (11.3%). Due to toxicity, 6 patients discontinued study treatment; 14 and 3 patients had a Gem and Ctx dose reduction respectively. Among the nine responders, 8 experienced a skin rash of at least grade 2, suggesting a relationship between skin toxicity and efficacy.

Conclusions: Our study met its endpoint, i.e., a PFS rate of 46% at 6 months, suggesting that Gem-Ctx combination had promising activity with a manageable toxicity profile in advanced CCK. Adding Ctx to the new standard of care Gem-cisplatin deserves further investigations in CCK.

[Table: see text]

Prospective randomized study comparing hepatic intra-arterial injection of Yttrium-90 resin-microspheres (HAI-Y90) with protracted IV 5FU (5FU CI) versus 5FU CI alone for patients with liver-limited metastatic colorectal cancer (LMCRC) refractory to standard chemotherapy (CT)

4096

Background: Chemorefractory LMCRC has a poor prognosis. We hypothesized a significant improvement of the patient's outcome after internal radiotherapy of the hepatic metastases with HAI-Y90 given along with 5FU CI over 5FU CI alone. Methods: This prospective, multicentric, randomized trial compared arm A: 5FU CI (300 mg/m2 D1–14 q3weeks) with arm B: HAI-Y90 and 5FU CI (225 mg/m2 D1–14 followed by 300 mg/m2 D1–14 q3weeks) until disease progression. Eligibility criteria were: chemo-refractory (5FU, oxaliplatin, irinotecan) LMCRC, PS max 2, normal direct bilirubin, and no lung shunting. Primary endpoint was time to liver progression (TTLP). Secondary endpoints were time to progression (TTP), overall survival (OS) and safety. Cross-over (HAI-Y90 monotherapy) was permitted in arm A after disease progression. Analysis was by intention to treat. To detect an increase in median TTLP from 6 to 18 weeks, 35 local progressions were needed (alpha 5%, power 90%). Distribution of time to events variables was modelled through Cox regression (likelihood ratio tests). Results: Trial randomized 46 patients (pts) of whom 44 were eligible for analysis (23 in arm A and 21 in arm B). Pts’ characteristics in the 2 arms were well balanced. Local progression was documented in 41 pts. Median length of follow-up was 108 weeks. Results are summarized in the table . Treatment was well tolerated with few side effects reported, essentially grade 3 asthenia (5 pts; 22%) in arm A. Most pts (25/44) received further treatment after local progression, including 10 pts with cross-over to HAI-Y90 in arm A, which may explain to some degree the lack of difference in OS. Conclusions: HAI-Y90 with 5FU CI significantly improves TTLP and TTP over 5FU CI alone and is a valid salvage therapeutic option for chemo-refractory LMCRC.

[Table: see text]

No significant financial relationships to disclose.

Phase I trial of zalutumumab and irinotecan in metastatic colorectal cancer patients who have failed irinotecan- and cetuximab-based therapy

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Background: Zalutumumab is a novel human IgG1 anti-EGFR mAb. We investigated the safety of zalutumumab and irinotecan in heavily pretreated mCRC patients. Methods: Metastatic CRC patients with documented progression (PD) during or within 6 months of stopping cetuximab and irinotecan based therapy were eligible. No prior treatment with anti-EGFR antibodies other than cetuximab was allowed. Patients received weekly doses of zalutumumab 8mg/kg and 16 mg/kg respectively in combination with irinotecan (180 mg/m2) every second week until PD or unacceptable toxicity. Results: The maximum tolerated dose was not reached and no patients experienced any dose limiting toxicity. At data cut-off (18-Dec-08) 4 patients had died (no cases of death were considered related to zalutumumab), 4 were off study due to PD and 1 was still ongoing ( Table 1 ). In total, 6 patients experienced one or more grade 3/4 toxicities (diarrhea 2; neutropenia 2; leucopenia 1; abdominal pain 1; pulmonary embolism 1; alopecia 1). Conclusions: Zalutumumab can be safely administrated in doses up to 16mg/kg in combination with irinotecan in mCRC patients failing cetuximab and irinotecan based therapy. Zalutumumab and irinotecan resulted in durable stable disease warranting further investigation of this regimen.

[Table: see text]

[Table: see text]

A phase Ib/II trial of AMG 655 and panitumumab (pmab) for the treatment (tx) of metastatic colorectal cancer (mCRC): Safety results

4130^

Introduction: Pmab is a fully human antibody targeting the epidermal growth factor receptor that is approved as monotherapy for mCRC in the US, EU, and Canada. AMG 655 is an investigational, fully human agonistic antibody against death receptor 5. This is the first study to evaluate the safety, tolerability, and efficacy of AMG 655 and pmab for the tx of mCRC. Methods: Eligible patients (pts) were ≥ 18 years old, had ECOG status 0–1, radiographic disease progression (PD) during or after tx with fluoropyrimidine, irinotecan, and/or oxaliplatin chemotherapy for mCRC. This is a 2-part study: in part 1 (n∼6–27 pts), the primary endpoint is the incidence of dose-limiting toxicities (DLTs); in part 2 (n∼38–41 pts), the primary endpoint is objective response rate per modified RECIST. Secondary endpoints for both parts include efficacy, pharmacokinetics (PK), and antibody formation. In part 1, pts received pmab 6 mg/kg Q2W plus AMG 655 at a starting dose of 10 mg/kg (evaluation of subsequent doses of 3 mg/kg or 1 mg/kg if needed; 6–9 pts at each dose) by sequential intravenous infusion at week 1 and Q2W thereafter until PD or intolerability. The tolerable dose in part 1 was selected for part 2. Results: We describe here the safety of the first 15 pts (n=5 part 1; n=10 part 2) after ≥ 8 weeks on study. Eight (53%) pts were women, 14 (93%) pts were white, and 9 (60%) pts had ECOG 1. Median (range) age was 61 (38–77) years. All pts received pmab 6 mg/kg and AMG 655 10 mg/kg Q2W. Median (range) follow-up time was 15.4 (9–31) weeks. There were no DLTs in part 1, thus AMG 655 10 mg/kg Q2W was selected for part 2. One (7%) pt had a tx-related adverse event (AE) ≥ grade (gr) 3: gr 3 hypomagnesemia. Tx-emergent Aes ≥ 25% are shown ( Table ). Laboratory values ≥ gr 3: one gr 3 AST and ALT; one gr 3 lipase. From intensive PK samples from the first 6 pts, pmab had no apparent impact on the PK of AMG 655. Conclusions: AMG 655 and pmab can be safely combined in later lines of tx for mCRC. The study is ongoing. Safety results for additional pts will be presented.

[Table: see text]

[Table: see text]

ASCO Conflict of Interest Policy and Exceptions

In compliance with the guidelines established by the ASCO Conflict of Interest Policy (J Clin Oncol. 2006 Jan 20;24[3]:519–521) and the Accreditation Council for Continuing Medical Education (ACCME), ASCO strives to promote balance, independence, objectivity, and scientific rigor through disclosure of financial and other interests, and identification and management of potential conflicts. According to the ASCO Conflict of Interest Policy, the following financial and other relationships must be disclosed: employment or leadership position, consultant or advisory role, stock ownership, honoraria, research funding, expert testimony, and other remuneration (J Clin Oncol. 2006 Jan 20;24[3]:520). The ASCO Conflict of Interest Policy disclosure requirements apply to all authors who submit abstracts to the Annual Meeting.

For clinical trials that began accrual on or after April 29, 2004, ASCO's Policy places some restrictions on the financial relationships of principal investigators (J Clin Oncol. 2006 Jan 20;24[3]:521). If a principal investigator holds any restricted relationships, his or her abstract will be ineligible for placement in the 2009 Annual Meeting unless the ASCO Ethics Committee grants an exception. Among the circumstances that might justify an exception are that the principal investigator (1) is a widely acknowledged expert in a particular therapeutic area; (2) is the inventor of a unique technology or treatment being evaluated in the clinical trial; or (3) is involved in international clinical oncology research and has acted consistently with recognized international standards of ethics in the conduct of clinical research. NIH-sponsored trials are exempt from the Policy restrictions. Abstracts for which authors requested and have been granted an exception in accordance with ASCO's Policy are designated with a caret symbol (^) in the Annual Meeting Proceedings.

For more information about the ASCO Conflict of Interest Policy and the exceptions process, please visit www.asco.org/conflictofinterest .

Correlation of CXCR4 expression in resected pancreatic adenocarcinoma (PA) with relapse and survival after adjuvant radiochemotherapy (RCT)

e22022

Background: The chemoreceptors CXCR4, CXCR7 and the hypoxia inductible factor-1 alpha (HIF-1α) are implicated in PA growth, dissemination and angiogenesis. These protagonists are expected to play a key role in radiotherapy and chemotherapy resistance in PA. Methods: We conducted a retrospective study of patients undergoing curative surgery (R0 resection) for PA between 2001 and 2006 in our institution. All were treated with adjuvant RCT (treatment group). The treatment group was case-matched with resected PA patients who did not receive any adjuvant therapy (control group). FFPE specimens were subjected to immunohistochemical analysis using tissue microarray and monoclonal antibodies against human CXCR4, CXCR7, and HIF-1α. Based on the intensity (I) and the extend (E) of staining, cases were stratified into those with high (E x I>3) or low (E x I ≤ 3) expression of CXCR4, CXCR7 and HIF-1α and results were correlated with disease-free survival (DFS) and overall survival (OS). Results: 31 PA patients (median age: 57years, range: 39–76) were analysed in the treatment group and 30 (median age: 59 years, range: 38–81) in the control group. The two groups were well-matched in terms of age, sex, tumor stage (T1-T2 vs T3-T4), tumor differentiation (poor vs well-moderate), lymph node (LN) status (N0 vs N+), lymphatic and vascular embols. In univariate analysis, CXCR4 expression and LN status were associated with DFS and OS (OS, CXCR4low/high: HR, 5.43, 95%CI: 2.03–14.49, p=0.001; N0/N+: HR: 4.62, 95% CI, 1.33–13.12, p=0.016; DFS: CXCR4low/ CXCR4high : HR, 3.01, 95%CI: 1.21–7.46, p=0.018; N0/N+: HR: 3.30, 95% CI, 1.09–9.90, p=0.034) in the treatment group while in the control group LN status was the only variable significantly correlated with DFS and OS. CXCR4 appeared to be the only independant predictor for DFS (CXCR4low/high: HR, 4.95, 95%CI: 1.68–14.71, p=0.007) and OS (CXCR4low/high: HR, 4.76, 95%CI: 2.03–14.49, p=0.004) in the treatment group but not in the control group. Conclusions: CXCR4 was an independant predictor for DFS and OS after adjuvant RCT in resected PA patients. This chemoreceptor could be implicated in the resistance of pancreatic cancer cells to RCT and its targeted inhibition deserves clinical evaluation.

No significant financial relationships to disclose.

Dose-finding study using oxaliplatin (Ox) in combination with fixed dose gemcitabine (Gem) and radiotherapy (RT) in patients with locally advanced pancreatic or biliary tract cancer (PBCa)

14028

Background: Prognosis of inoperable PBCa is poor. Large randomized studies in pancreatic cancer showed a better survival in patients (pts) with locally advanced (LA) in comparison with metastatic disease. Data on radiochemotherapy are scarce in pts with LA disease. Therefore, we performed this multicenter, phase I study on the combination of radiotherapy and Gem/Ox. This regimen showed superior activity to Gem alone in pancreatic cancer (Louvet C et al. JCO 2005;23:3509–16.) Methods: After signed informed consent, pts with LA pancreatic cancer (n = 14) or biliary tract cancer (n=1) were included. They received two cycles of Gem/Ox1 followed by 5 weeks of RT (25 fractions of 1.8 Gy up to a total dose of 45 Gy) in combination with a weekly fixed dose of Gem (300 mg/m2 in 30’) and an escalating weekly dose of Ox (levels: 40/50/60 mg/m2). NCI-CTC 2.0 was used weekly to score treatment-related toxicity in all pts. Results: Today, 15 pts. with a median age of 61 y (range: 44–74), median Karnofsky performance score 90 (range: 70–100) and M/F = 8/7 were included. Upto 60 mg/m2 Ox, no disease limiting toxicity (DLT) occured. Grade 3 toxicity included nausea (n = 1), neutropenia (n = 3) and thrombocytopenia (n = 1). This latter patient was treated with 40 mg/m2 Ox and subsequently also experienced a grade 4. One patient receiving 50 mg/m2 Ox developed a grade 4 thrombocytopenia. Most frequent grade 1/2 toxicity was nausea (n = 8, 53%), thrombocytopenia (n = 5, 33%) and diarrhea (n = 5, 30%). Fourteen out of 15 received the full course of radiotherapy. Median time to progression (TTP) is 6.7 months (95% CI: 3.7–13.5). Thirteen out of 15 pts. are still alive. Conclusions: Combination of radiotherapy and Gemcitabin/Oxaliplatin in pts with LA pancreaticobiliairy cancer is feasible and well-tolerated. The long TTP underlines the potential activity of this regimen. As no DLT has been reached, we will use a dose of 60 mg/m2 Ox for further evaluation.

[Table: see text]

Clinical impact of biliary drainage and jaundice resolution in patients with obstructive metastases at the hilum

OBJECTIVES

For patients presenting with progressive liver or lymph node metastases (LM) causing obstructive jaundice, survival without adequate biliary drainage is very brief. The aim of this study was to assess the impact of endoscopic drainage for biliary obstruction secondary to LM at the hilum on subsequent administration of chemotherapy and on patient outcome.

METHODS

Thirty-five patients were studied and underwent insertion of plastic and/or metal stents, endoscopically (80%) or percutaneously and endoscopically (20%), to obtain complete resolution of jaundice. LM originated from colon (n = 16), gastric (n = 5), breast (n = 5), pancreatic (n = 3), and miscellaneous cancers (n = 6). Bile duct strictures were Bismuth type I-II in 13 patients and type III in 22.

RESULTS

The overall rate of success (i.e., complete resolution of jaundice) was 86% after a median of three procedures per patient (range, 1-7). Pruritus, jaundice, nausea, abdominal pain, and anorexia improved significantly in 88, 86, 75, 66, and 50% of cases, respectively. Overall median survival was 4 months and was 6.5 versus 1.8 months (p < 0.05) in the groups of patients whose jaundice resolved completely versus incompletely. The type of stricture did not affect survival. Patients with colon and breast cancer who were eligible for second line chemotherapy after optimal drainage had the longest survival (12-16 months).

CONCLUSIONS

In our patients with obstructive LM, endoscopic biliary drainage completely resolved jaundice in 86% and improved clinical symptoms and survival, thus enabling these patients to have additional chemotherapy.

Factors influencing survival at one year in patients with nonbiliary hepatic parenchymal cirrhosis

Transplantation may be considered for patients with advanced cirrhosis, however, adequate criteria for evaluating survival in those patients are ill-defined. The aim of the present study was to select, among several clinical and functional variables those that could best predict survival at one year. The data collected from 91 consecutive patients with parenchymal cirrhosis hospitalized in our center from February 1984 to January 1986 were subjected to stepwise logistic regression analysis. Death occurring during the first year following entry into the study was considered as a failure. During that period, there were no censored patients. Of 19 variables that entered into the analysis, only two were significant (P less than 0.01): presence (1: moderate; 2: severe) or absence (0) of ascites (A) and breath test (BT: % aminopyrine activity of administered dose at 2 hr). The logistic equation was: 1n (P/1 - P): - 1.95 A + 1.64 BT - 0.393, where P represented the probability of survival at one year. For each patient, P was calculated according to his A and BT values. Using a 0.7 probability cut-point to separate success from failure, 93% (70/75) of successes, 81% (13/16) of failures, and 91% (83/91) of both successes and failures could be correctly predicted. Predictive equations like the present preliminary one can be used in the future to better assess the risk of mortality in patients with parenchymal cirrhosis in whom liver transplantation is considered.

A new assessment of the normal ranges of the Farnsworth-Munsell 100-hue test scores

We gave the Farnsworth-Munsell 100-hue color vision test to 232 normal subjects between 10 and 80 years of age. One half the subjects underwent binocular testing followed by monocular testing. In the other half monocular testing preceded binocular testing. Performance was better with both eyes than with either eye alone. The worst performance occurred on monocular tests in subjects without previous experience with the task (that is, those for whom this was the first test). The well-known age trend was apparent (children and elderly have the worst color vision). New data are provided for judging the point at which the total error score may be considered pathologic.