International multicenter study comparing COVID-19 in patients with cancer to patients without cancer: Impact of risk factors and treatment modalities on survivorship

Background

In this international multicenter study, we aimed to determine the independent risk factors associated with increased 30 day mortality and the impact of cancer and novel treatment modalities in a large group of patients with and without cancer with COVID-19 from multiple countries.

Methods

We retrospectively collected de-identified data on a cohort of patients with and without cancer diagnosed with COVID-19 between January and November 2020 from 16 international centers.

Results

We analyzed 3966 COVID-19 confirmed patients, 1115 with cancer and 2851 without cancer patients. Patients with cancer were more likely to be pancytopenic and have a smoking history, pulmonary disorders, hypertension, diabetes mellitus, and corticosteroid use in the preceding 2 wk (p≤0.01). In addition, they were more likely to present with higher inflammatory biomarkers (D-dimer, ferritin, and procalcitonin) but were less likely to present with clinical symptoms (p≤0.01). By country-adjusted multivariable logistic regression analyses, cancer was not found to be an independent risk factor for 30 day mortality (p=0.18), whereas lymphopenia was independently associated with increased mortality in all patients and in patients with cancer. Older age (≥65y) was the strongest predictor of 30 day mortality in all patients (OR = 4.47, p<0.0001). Remdesivir was the only therapeutic agent independently associated with decreased 30 day mortality (OR = 0.64, p=0.036). Among patients on low-flow oxygen at admission, patients who received remdesivir had a lower 30 day mortality rate than those who did not (5.9 vs 17.6%; p=0.03).

Conclusions

Increased 30 day all-cause mortality from COVID-19 was not independently associated with cancer but was independently associated with lymphopenia often observed in hematolgic malignancy. Remdesivir, particularly in patients with cancer receiving low-flow oxygen, can reduce 30 day all-cause mortality.

Funding

National Cancer Institute and National Institutes of Health.

Risk Factors Associated with Severe Clostridioides difficile Infection in Patients with Cancer

INTRODUCTION

Antibiotic use is a risk factor for Clostridioides difficile infection (CDI). Few studies have correlated use of prior antibiotic classes with CDI, microbiome composition, and disease severity in patients with cancer. We hypothesized that previous antibiotic exposure and fecal microbiome composition at time of presentation are risk factors for severe CDI in patients with cancer.

METHODS

This non-interventional, prospective, cohort study examined 200 patients with cancer who had their first episode or first recurrence of CDI. C. difficile was identified using nucleic acid amplification testing. Univariate analysis was used to determine significant risk factors for severe CDI. Fecal microbiome composition was determined by sequencing the V3/V4 region of 16 s rDNA encoding gene. Differential abundance analyses were used to single out significant microbial features which differed across severity levels.

RESULTS

On univariate analysis, factors associated with severe CDI included the presence of toxin A/B in stools (odds ratio [OR] 2.14 [1.05-4.36] p = 0.04 and prior 90-day metronidazole use (OR 2.66 [1.09-6.50] p = 0.03). Although alpha and beta diversity was similar between disease severity groups and toxin A/B in stools, increased abundance of Bacteroides uniformis, Ruminococcaceae, and Citrobacter koseri were associated with protection from severe CDI (p < 0.05) and depletion of anaerobes was higher in patients with prior metronidazole exposure.

CONCLUSION

Use of metronidazole for non-CDI indications within 90 days prior to diagnosis and presence of toxin A/B in stools were associated with severe CDI. Findings provide valuable insights into risk factors for severe CDI in an underserved population with cancer that warrants further exploration.

1086. COVID-19 in a Comprehensive Cancer Center: 2020-2022

Background

Patients with COVID-19 and underlying malignancies, particularly those receiving immunosuppressive therapy, are at higher risk of severe COVID-19 disease.

Our retrospective cohort study examines the outcomes of COVID-19 infection in patients with different underlying malignancies admitted to a 710- beds comprehensive cancer center during the first 2 years of the pandemic.

Methods

All patients with cancer admitted to MD Anderson Cancer Center with a positive PCR test for SARS-CoV-2 were included in a clinical case registry from 3/22/20 (first hospitalized COVID-19 patient) to 3/31/22. This clinical registry was approved at the beginning of the COVID-19 pandemic by the Quality Improvement Assessment Board at MDACC. Clinical information including type of malignancy, date of admission, length of stay, need for invasive mechanical ventilation (IMV), and in-hospital mortality was obtained from their electronic medical records. Statistical analysis was performed using a two-proportion z-test where p&lt; 0.05 was considered significant.

Results

A total of 1748 patients with cancer and COVID-19 infection were admitted over a 2-year period (3.2% of total hospital admissions during the same period), 49% had hematological malignancies (HM) (see table). Patients with HM had significantly higher readmission rates (17.3% vs 9.1%, p&lt; 0.0001), IMV rates (7.8% vs 4.4%, p=0.0029), and inpatient mortality rates (13.6% vs 7.1%, p&lt; 0.0001). compared to patients with solid tumors (ST). Total mortality rate was 8.8% (154 patients), even higher in patients with different types of HM, such as lymphoma 18.1%, AML 14.2%, MM 8.4%, CML 7.1% while the mortality for ST was 7.1%.

COVID-19 Hospitalized Patients at UT-MDACC (3/22/20-3/31/22)

UT-MDACC: The University of Texas MD Anderson Cancer Center

*p-value &lt;0.01 for z-test of 2 proportions (one-tailed)

Conclusion

HM patients hospitalized with COVID-19 infection had more severe disease and worse outcomes based on readmissions, IMV, and mortality rates. Preventive measures, prompt diagnosis and early treatments should be considered on this patient population.

Disclosures

Roy F. Chemaly, MD/MPH, Karius: Advisor/Consultant|Karius: Grant/Research Support.

International Multicenter Study Comparing Cancer to Non-Cancer Patients with COVID-19: Impact of Risk Factors and Treatment Modalities on Survivorship

Background

In this international multicenter study we aimed to determine the independent risk factors associated with increased 30-day mortality and the impact of novel treatment modalities in a large group of cancer and non-cancer patients with COVID-19 from multiple countries.

Methods

We retrospectively collected de-identified data on a cohort of cancer and non-cancer patients diagnosed with COVID-19 between January and November 2020, from 16 international centers.

Results

We analyzed 3966 COVID-19 confirmed patients, 1115 cancer and 2851 non-cancer patients. Cancer patients were more likely to be pancytopenic, and have a smoking history, pulmonary disorders, hypertension, diabetes mellitus, and corticosteroid use in the preceding two weeks (p≤0.01). In addition, they were more likely to present with higher inflammatory biomarkers (D-dimer, ferritin and procalcitonin), but were less likely to present with clinical symptoms (p≤0.01). By multivariable logistic regression analysis, cancer was an independent risk factor for 30-day mortality (OR 1.46; 95% CI 1.03 to 2.07; p=0.035). Older age (≥65 years) was the strongest predictor of 30-day mortality in all patients (OR 4.55; 95% CI 3.34 to6.20; p< 0.0001). Remdesivir was the only therapeutic agent independently associated with decreased 30-day mortality (OR 0.58; CI 0.39-0.88; p=0.009). Among patients on low-flow oxygen at admission, patients who received remdesivir had a lower 30-day mortality rate than those who did not (5.9% vs 17.6%; p=0.03).

Conclusions

Cancer is an independent risk factor for increased 30-day all-cause mortality from COVID-19. Remdesivir, particularly in patients receiving low-flow oxygen, can reduce 30-day all-cause mortality.

Condensed Abstract

In this large multicenter worldwide study of 4015 patients with COVID-19 that included 1115 patients with cancer, we found that cancer is an independent risk factor for increased 30-day all-cause mortality. Remdesivir is a promising treatment modality to reduce 30-day all-cause mortality.

22. International Multicenter Study Comparing Cancer to Non-Cancer Patients with COVID-19: Impact of Risk Factors and Treatment Modalities on Outcome

Background

Given the limited collaborative international studies that evaluated COVID-19 in patients with cancer in comparison to patients without cancer, we aimed to determine the independent risk factors associated with increased 30-day mortality and the impact of novel treatment modalities in a large group of cancer and non-cancer patients with COVID-19 from multiple countries.

Methods

We retrospectively collected de-identified data on cancer and non-cancer patients diagnosed with COVID-19 between January and November 2020, at 16 centers in Asia, Australia, Europe, North America, and South America. A logistic regression model was used to identify independent predictors of all-cause mortality within 30 days after COVID-19 diagnosis.

Results

Of the total 4015 COVID-19 confirmed patients entered, we analyzed 3966 patients, 1115 cancer and 2851 non-cancer patients. Cancer patients were older than non-cancer patients (median age, 61 vs 50 years; p< 0.0001); more likely to be pancytopenic , had pulmonary disorders, hypertension, diabetes mellitus. In addition, they were more likely to present with higher inflammatory biomarkers (D-dimer, ferritin and procalcitonin), but were less likely to present with clinical symptoms. By multivariable logistic regression analysis, cancer was an independent risk factor for 30-day mortality (OR 1.46; 95% CI 1.03 to 2.07; p=0.035). Older age (≥65 years) was the strongest predictor of 30-day mortality in all patients (OR 4.55; 95% CI 3.34 to 6.20; p< 0.0001). Remdesivir was the only therapeutic agent independently associated with decreased 30-day mortality (OR 0.58; CI 0.39-0.88; p=0.009). Among patients on low-flow oxygen at admission, patients who received remdesivir had a lower 30-day mortality rate than those who were on high flow oxygen (5.9% vs 17.6%; p=0.03). Patients transfused with convalescent plasma within 1 day of diagnosis had a lower 30-day mortality rate than those transfused later (1% vs 7%, p=0.04).

Conclusion

Cancer is an independent risk factor for increased 30-day all-cause mortality from COVID-19. Remdesivir, particularly in patients receiving low-flow oxygen, can reduce 30-day all-cause mortality, as well as convalescent plasma given early after COVID-19 diagnosis.

Disclosures

Roy F. Chemaly, MD, MPH, FACP, FIDSA, AiCuris (Grant/Research Support)Ansun Biopharma (Consultant, Grant/Research Support)Chimerix (Consultant, Grant/Research Support)Clinigen (Consultant)Genentech (Consultant, Grant/Research Support)Janssen (Consultant, Grant/Research Support)Karius (Grant/Research Support)Merck (Consultant, Grant/Research Support)Molecular Partners (Consultant, Advisor or Review Panel member)Novartis (Grant/Research Support)Oxford Immunotec (Consultant, Grant/Research Support)Partner Therapeutics (Consultant)Pulmotec (Consultant, Grant/Research Support)Shire/Takeda (Consultant, Grant/Research Support)Viracor (Grant/Research Support)Xenex (Grant/Research Support) Fareed Khawaja, MBBS, Eurofins Viracor (Research Grant or Support) Monica Slavin, MBBS,MD, F2G (Advisor or Review Panel member)Merck (Advisor or Review Panel member)Pfizer (Advisor or Review Panel member) Dimitrios P. Kontoyiannis, MD, Astellas (Consultant)Cidara Therapeutics (Advisor or Review Panel member)Gilead Sciences (Consultant, Grant/Research Support, Other Financial or Material Support, Honoraria)

Clostridioides difficile Infection in Cancer and Immunocompromised Patients: Relevance of a Two-step Diagnostic Algorithm and Infecting Ribotypes on Clinical Outcomes

BACKGROUND

Patients with cancer are particularly vulnerable to Clostridioides difficile infection (CDI). Guidelines recommend a two-step diagnostic algorithm to differentiate carriers from CDI; however, there are limited data for this approach while including other confounding risk factors for diarrhea such as radiation, cytotoxic chemotherapy, and adoptive cell based therapies.

METHODS

We conducted a prospective, non-interventional, single center, cohort study of cancer patients with acute diarrhea and C. difficile, identified in stools by nucleic acid amplification tests (NAAT) and culture. Fecal toxin A/B was detected by enzyme immunoassay (EIA) and isolates were ribotyped using 16s rRNA fluorescent sequencing. Patients were followed for 90 days to compare outcomes according to malignancy type, infecting ribotype, and EIA status.

RESULTS

We followed 227 patients with a positive NAAT. Of these, 87% were hospitalized and 83% had an active malignancy. EIA was confirmed positive in 80/227 (35%) of patients. Those with EIA+ were older (60 ± 18 years vs 54 ± 19 years., P = .01), more likely to fail therapy [24/80 (30%) vs 26/147 (18%), P = .04] and experience recurrence [20/80 (25%) vs 21/147(14%), P < .05]. We found a low prevalence (22%) of ribotypes historically associated with poor outcomes (002, 018, 027, 56, F078-126, 244) but their presence were associated with treatment failure [17/50 (34%) vs 33/177 (19%), P = .02].

CONCLUSIONS

When compared to cancer patients with fecal NAAT+/EIA-, patients with NAAT+/EIA+ CDI are less likely to respond to therapy and more likely to experience recurrence, particularly when due to ribotypes associated with poor outcomes.

High Levels of Common Cold Coronavirus Antibodies in Convalescent Plasma Are Associated With Improved Survival in COVID-19 Patients

Background

COVID-19 Convalescent plasma (CCP) is safe and effective, particularly if given at an early stage of the disease. Our study aimed to identify an association between survival and specific antibodies found in CCP.

Patients and Methods

Patients ≥18 years of age who were hospitalized with moderate to severe COVID-19 infection and received CCP at the MD Anderson Cancer Center between 4/30/2020 and 8/20/2020 were included in the study. We quantified the levels of anti-SARS-CoV-2 antibodies, as well as antibodies against antigens of other coronavirus strains, in the CCP units and compared antibody levels with patient outcomes. For each antibody, a Bayesian exponential survival time regression model including prognostic variables was fit, and the posterior probability of a beneficial effect (PBE) of higher antibody level on survival time was computed.

Results

CCP was administered to 44 cancer patients. The median age was 60 years (range 37-84) and 19 (43%) were female. Twelve patients (27%) died of COVID-19-related complications. Higher levels of two non-SARS-CoV-2-specific antibodies, anti-HCoV-OC43 spike IgG and anti-HCoV-HKU1 spike IgG, had PBE = 1.00, and 4 SARS-CoV-2-specific antibodies had PBEs between 0.90 and 0.95. Other factors associated with better survival were shorter time to CCP administration, younger age, and female sex.

Conclusions

Common cold coronavirus spike IgG antibodies anti-HCoV-OC43 and anti-HCoV-HKU1 may target a common domain for SARS-CoV-2 and other coronaviruses. They provide a promising therapeutic target for monoclonal antibody production.

High levels of common cold coronavirus antibodies in convalescent plasma are associated with improved survival in COVID-19 patients

BACKGROUND

COVID-19 Convalescent plasma (CCP) is safe and effective, particularly if given at an early stage of the disease. Our study aimed to identify an association between survival and specific antibodies found in CCP.

PATIENTS AND METHODS

Patients ≥18 years of age who were hospitalized with moderate to severe COVID-19 infection and received CCP at the MD Anderson Cancer Center between 4/30/2020 and 8/20/2020 were included in the study. We quantified the levels of anti-SARS-CoV-2 antibodies, as well as antibodies against antigens of other coronavirus strains, in the CCP units and compared antibody levels with patient outcomes. For each antibody, a Bayesian exponential survival time regression model including prognostic variables was fit, and the posterior probability of a beneficial effect (PBE) of higher antibody level on survival time was computed.

RESULTS

CCP was administered to 44 cancer patients. The median age was 60 years (range 37-84) and 19 (43%) were female. Twelve patients (27%) died of COVID-19-related complications. Higher levels of two non-SARS-CoV-2-specific antibodies, anti-HCoV-OC43 spike IgG and anti-HCoV-HKU1 spike IgG, had PBE = 1.00, and 4 SARS-CoV-2-specific antibodies had PBEs between 0.90 and 0.95. Other factors associated with better survival were shorter time to CCP administration, younger age, and female sex.

CONCLUSIONS

Common cold coronavirus spike IgG antibodies anti-HCoV-OC43 and anti-HCoV-HKU1 may target a common domain for SARS-CoV-2 and other coronaviruses. They provide a promising therapeutic target for monoclonal antibody production.

372. Comparing the Outcome of COVID-19 in Cancer and Non-Cancer Patients: an International Multicenter Study

Background

Our objective was to describe the clinical course, risk factors and outcomes of patients infected with COVID-19 around the globe comparing cancer to non-cancer patients.

Methods

We conducted a retrospective cohort study of COVID-19 confirmed cases through an international multicenter collaboration including 17 centers around the world including the United States of America, Brazil, Europe, Far East, Middle East and Australia from January to date. We evaluated the patients’ clinical characteristics, clinical course of the disease, hospitalization and outcome. Death was considered to be COVID-associated if it occurred within 30 days from the time of diagnosis.

Results

Preliminary data on 571 patients included 186 cancer patients and 385 non-cancer patients.

Cancer patients were more likely to have COPD and received steroids but were less likely to have COVID-related symptoms compared to non-cancer patients (84% vs 97%, p< 0.0001). The rate of pneumonia with hypoxia, non-invasive ventilation and mechanical ventilation were similar in both groups. Despite the fact that hospital admissions were significantly higher in non-cancer patients (70% vs 56%, p< 0.001), promising antiviral and immune-related therapy including remdesivir, convalescent plasma and immunomodulators were more commonly used in cancer patients compared to non-cancer patients (P=0.04). Cancer patients had a higher COVID-associated mortality rate compared to non-cancer patients (20% vs 11%, p=0.006).

Conclusion

Despite the fact that cancer patients received more frequent antiviral and immune-related therapy, the mortality rate among cancer patients was significantly higher than non-cancer patients.

Disclosures

Roy F. Chemaly, MD, MPH, FACP, FIDSA, Chimerix (Consultant, Research Grant or Support)Clinigen (Consultant)Merck (Consultant, Research Grant or Support)Novartis (Research Grant or Support)Oxford Immunotec (Consultant, Research Grant or Support)Shire/Takeda (Research Grant or Support)Viracor (Research Grant or Support) Issam I. Raad, MD, Citius (Other Financial or Material Support, Ownership interest)Cook Medical (Grant/Research Support)Inventive Protocol (Other Financial or Material Support, Ownership interest)Novel Anti-Infective Technologies (Shareholder, Other Financial or Material Support, Ownership interest)

OP0297 EFFICACY AND SAFETY OF ROMOSOZUMAB AMONG POSTMENOPAUSAL WOMEN WITH OSTEOPOROSIS AND MILD-TO-MODERATE CHRONIC KIDNEY DISEASE

Background:

Osteoporosis and renal insufficiency are coexisting disease states in a substantial proportion of postmenopausal women. Since bisphosphonates are generally contraindicated in patients with estimated glomerular filtration rate (eGFR) <35 mL/min, it is important to evaluate other osteoporosis treatments in this setting.

Objectives:

To determine if baseline renal function affects the efficacy and safety of romosozumab.

Methods:

We performed post hoc analyses of two clinical trials of romosozumab in postmenopausal women with osteoporosis. In ARCH (NCT01631214), 4,093 patients were randomised 1:1 to romosozumab 210 mg monthly or alendronate 70 mg weekly for 12 months (mean age: 74.3 years; 96.1% with prevalent vertebral fractures [VFx]). In FRAME (NCT01575834), 7,180 patients were randomised 1:1 to romosozumab 210 mg or placebo monthly for 12 months (mean age: 70.9 years; 18.3% with prevalent VFx). For these analyses, patients were categorised by baseline eGFR (mL/min/1.73m2): normal renal function (eGFR ≥90), mild renal insufficiency (eGFR 60–89), or moderate renal insufficiency (eGFR 30–59). Least squares mean (LSM) percent change from baseline in bone mineral density (BMD) at the lumbar spine, total hip, and femoral neck; incidence of new VFx and adverse events (AEs); and changes in renal function were assessed for each eGFR category at Month 12 of the double-blind treatment period.

Results:

At baseline, most patients had mild/moderate renal insufficiency: 84% in ARCH, 88% in FRAME. In both studies, change from baseline in BMD was significantly higher in the romosozumab group across baseline eGFR categories (Figure). There was an interaction between BMD increase and renal function, and although BMD increase was not as large in women with impaired renal function, differences between romosozumab and control groups remained significant (Figure). In ARCH, among patients with eGFR ≥90, 60–89, and 30–59, the incidence of new VFx (romosozumab vs alendronate) at Month 12 was 3.3% vs 7.3%, 3.2% vs 3.9%, and 3.4% vs 6.2% in ARCH. In FRAME, the incidence of new VFx (romosozumab vs placebo) at Month 12 was 0.5% vs 3.0%, 0.4% vs 1.5%, and 0.6% vs 2.1%.

In both studies, the incidences of AEs and serious AEs were similar in both treatment groups within and across eGFR categories. AEs of mild-to-moderate hypocalcaemia (investigator reported) occurred in two patients in ARCH (one romosozumab [eGFR 60–89] and one alendronate [eGFR ≥90]), and one patient in FRAME (romosozumab [eGFR 60–89]). Five patients in ARCH (all in the alendronate group) and 19 patients in FRAME (14 romosozumab, 5 placebo) had decreases in serum Ca levels (albumin adjusted); in the romosozumab group all were mild (<LLN–8.0 mg/dL) or moderate (<8.0–7.0 mg/dL). A similar percentage of patients in each group had changes in renal function over 12 months of treatment.

Conclusion:

The efficacy and safety of romosozumab vs alendronate or placebo was similar among postmenopausal women with osteoporosis and different levels of renal function.

Acknowledgments:

This study was funded by Amgen, Astellas and UCB Pharma. Editorial services were provided by Costello Medical.

Disclosure of Interests:

Paul Miller Grant/research support from: Amgen, Radius Health, Ultragenyx, Consultant of: Amgen, Radius Health, Jonathan Adachi Consultant of: Amgen, Speakers bureau: Amgen, Ben-Hur Albergaria Consultant of: Amgen Inc., Eli Lilly, Speakers bureau: Amgen Inc., Eli Lilly, Angela M Cheung Consultant of: Amgen, Eli Lilly, Arkadi Chines Shareholder of: Amgen Inc., Employee of: Amgen Inc., Evelien Gielen Consultant of: Amgen Inc., Takeda, Sandoz and UCB Pharma, Speakers bureau: Amgen Inc., Takeda, Sandoz and UCB Pharma, Bente Langdahl Grant/research support from: Amgen, NovoNordisk, Consultant of: Amgen Inc., Eli Lilly, UCB Pharma, Akimitsu Miyauchi Consultant of: Amgen Inc., Astellas BioPharma K.K., Teijin Pharma, Mary Oates Shareholder of: Amgen Inc., Employee of: Amgen Inc., Ian Reid Consultant of: Amgen Inc., Eli Lilly, Speakers bureau: Amgen Inc., Eli Lilly, Norma Ruiz Santiago Shareholder of: Amgen Inc., Employee of: Amgen Inc., Mark Vanderkelen Employee of: UCB Pharma, Wenjing Yang Shareholder of: Amgen Inc., Employee of: Amgen Inc., Zhigang Yu Shareholder of: Amgen Inc., Employee of: Amgen Inc.

2211. Impact of Early Fiberoptic Bronchoscopy on Microbiological Diagnostic Rate and Clinical Outcomes of Pneumonia in Acute Leukemia Patients

Background

Fiberoptic bronchoscopy with BAL (FOB) remains the cornerstone in the diagnosis of pneumonia in immunocompromised patients; however, there is no uniform agreement on the best timing for FOB, and its impact on microbiological diagnostic rate and clinical outcome has not been established.

Methods

Retrospective study (October 2017–December 2017, July 2018–January 2019) at MD Anderson Cancer Center. The medical records of adult patients with AML, MDS or ALL who developed pneumonia (CAP, HCAP, HAP excluding VAP) and underwent FOB were reviewed. By definition, patients who underwent FOB within 48 hours after the diagnosis of pneumonia were categorized as early FOB group. We compared demographic, clinical, microbiological data, and outcomes between two groups. Data were analyzed via χ ², Fisher’s exact and Wilcoxon rank-sum test and logistic regression.

Results

Of 140 patients included, 33 patients (24%) had early FOB and 107 patients (76%) had late FOB. There was no significant difference between two groups in demographic features, radiological findings, ANC and pneumonia severity index. Microbiological diagnostic rate of FOB did not differ between early FOB and late FOB: identification of pathogenic microorganisms (33.3% vs. 36.5%, p = 0.837), bacteria (6.1% vs. 13.1%, P = 0.36), fungi (18.2% vs. 12.2%, P = 0.39) and respiratory virus (12.1% vs. 16.8%, P = 0.6), respectively (Figures 1 and 2). On univariate analysis, the duration of intravenous antibacterial therapy was shorter in early FOB, with a median duration of 8.5 days (IQR 6.5–12) in early FOB and 11 days (IQR 8–18) in late FOB (P = 0.0047) (Figure 3). Multivariable logistic regression analysis showed that late FOB (OR 3.26, 95% CI 1.41 to 7.53, P = 0.0057) and negative bacterial culture on FOB (OR 3.06, 95% CI 1.01 to 9.22, P = 0.048) were significantly associated with longer duration of intravenous antibacterial therapy (≥10 days). There was no significant difference in ICU admission, 30-day and 60-day mortality and re-admission rate.

Conclusion

Early FOB was associated with shorter duration of intravenous antibacterial therapy for pneumonia in acute leukemia patients, which has an important impact on both optimization of antimicrobial therapy for patients and improvement of antimicrobial stewardship.

Disclosures

All authors: No reported disclosures.

P13.01 TERTpromoter methylation is significantly associated withTERTupregulation and tumor progression in pituitary adenomas

BACKGROUND

Activation of telomerase plays a critical role in tumor development. Somatic alterations in the promoter of the telomerase reverse transcriptase (TERT) gene are a major mechanism of upregulating telomerase. Several mechanisms have been associated with TERT abnormalities, including TERT promoter mutations or methylation. Mutations in the TERT promoter have been observed in a subset of brain tumors, especially in adult gliomas. In pituitary adenomas (PAs), however, TERT abnormalities are not fully understood. The present study aimed to investigate not only mutational but also methylation status changes in the TERT promoter in PAs and to analyze their correlations with clinical variables.

MATERIAL AND METHODS

We retrospectively studied 70 PAs consisting of 53 primary and 17 recurrent samples. Clinical data, including age at surgery, sex, tumor size, tumor subtype, resection rate, presence or absence of postoperative irradiation, and progression-free survival (PFS), were obtained from medical records. First, we investigated TERT promoter hotspot mutations via Sanger sequencing. Next, we quantified the methylation status of the TERT promoter using methylation-sensitive high-resolution melting analysis (MS-HRM). Finally, we investigated TERT mRNA expression levels using real-time quantitative PCR. Fisher’s exact test was applied to evaluate the statistical significance between TERT promoter methylation status and tumor recurrence. PFS was calculated using Kaplan-Meier estimates and compared between methylated with ummethylated PAs with the log-rank test. The correlation between TERT promoter methylation status and mRNA levels was analyzed with the Mann-Whitney U-test. PFS was analyzed using multivariate analysis with the Cox proportional hazards model and included the following variables: age, sex, tumor size, tumor subtype, resection rate, radiation therapy, and methylation status.

RESULTS

TERT promoter hotspot mutations were not observed in any PA sample. Nineteen percent of PAs exhibitedTERT promoter methylation, which was significantly predominant in recurrent PA samples. PFS was significantly shorter in the methylated cases than in the unmethylated cases. Higher TERT expression levels were correlated with methylation status.

CONCLUSION

We found that TERT promoter methylation upregulated TERT expression and was associated with shorter PFS in PAs. Our results suggest thatTERT promoter methylation may be a potential biomarker for predicting tumor recurrence in PAs.

P14.113 The role of maintenance high-dose methotrexate chemotherapy in elderly primary CNS lymphoma patients with complete response to induction immunochemotherapy

BACKGROUND

The addition of high-dose methotrexate (HD-MTX)-based chemotherapy to whole brain irradiation (WBRT) has improved the prognosis of primary central nervous system lymphoma (PCNSL). However, the high neurotoxicity rates observed, especially in the elderly, raised interest in chemotherapy-only treatments. Withholding radiotherapy substantially decreases the risk of neurotoxicity, however, disease control may be compromised. Therefore, developing a novel treatment for the elderly PCNSL patients (ePCNSL) is crucial. In the elderly who cannot tolerate WBRT as a consolidation, maintenance treatment may serve as a feasible approach after an initial response. We treated ePCNSL with induction immunochemotherapy with rituximab (RIT) and HD-MTX, maintenance chemotherapy with HD-MTX and deferred WBRT. Here, we retrospectively investigated the prognosis for ePCNSL that became CR after the induction chemotherapy.

MATERIAL AND METHODS

Newly diagnosed ePCNSL (median age: 74 years) received biweekly RIT/ HD-MTX (375 mg/m2/dose; 3.5g/m2/dose) for 6 cycles (induction) followed by monthly RIT/MTX for 2 cycles (consolidation) and then were treated differently according to the radiological response. With CR patients, HD-MTX was continued with every 3 months (maintenance) for 2 years. Patients who did not obtain consent for maintenance therapy were followed up.

RESULTS

Of the 42 ePCNSL (median age 74 years), 26 had CR after induction and consolidation, of which 18 cases were carried out maintenance (M +) and 8 cases were followed up (M-). The median age was 74 and 76, respectively. Median progression-free survival (mPFS) was 73 months in the M+ group and 24.6 months in the M- group. Median overall survival (mOS) is 92.5 months versus 27.6 months, respectively. Both mPFS (P= 0.025) and mOS (P =0.0003) were significantly prolonged by maintenance therapy. In addition, ePCNSL with tumors involvement of deep brain structure had a poor prognosis.

CONCLUSION

It was suggested that maintenance treatment with HD-MTX may improve the prognosis for ePCNSL that reached complete response after induction therapy.

2008. Effective and Early Diagnosis of Pneumonia in Patients With Acute Leukemia in a Comprehensive Cancer Center: How Can We Improve the Microbiological Diagnosis?

Background

Pneumonia is one of the main causes of morbi-mortality in acute leukemia (AL) patients. The positive yield of microbiology diagnosis is still significantly low. The aim of the study was to evaluate the possible impact of use of diagnostic methods (within first 48 hours of diagnosis) in AL patients with pneumonia during chemotherapy.

Methods

Retrospective study (January 2017–December 2017) at MD Anderson Cancer Center. The medical records of adult patients with AML, MDS, or ALL who developed CT-confirmed pneumonia after induction or second-line chemotherapy were reviewed, including demographic, clinical, microbiology data, and outcomes.

Results

During 2017, 174 patients with AL developed pneumonia confirmed by CT chest. Fifty (29%) of them during induction/second-line chemotherapy: 42 (84%) AML, five (10%) MDS, and three (6%) ALL. Thirty-one (62%) showed consolidation in CT, 14 (28%) nodules, and five (10%) both findings. Mean age was 65 (SD: 11.5, range: 24–87) years with 46% males. Thirty-three (66%) patients had neutropenia (ANC<500) at the time of pneumonia. ID was consulted in 38 (76%) and pulmonary in 37 (74%) patients. Bronchoscopy/BAL (bronch) was performed in only 24 (48%) patients, still with the highest diagnostic yield (13/24, 54%) compared with other diagnostic methods (sputum and blood cultures; and galactomannan, β-glucan, and cryptococcal antigen in serum). Twelve of 24 (50%) patients had an early bronch (within 48 hours), with higher identification of bacteria (3/12, 25%), fungi (2/12, 16.7%), and virus (3/12, 25%) compared with those 12 performed later. A trend of more viral infection (6/12, 50%), including CMV, was found in late-performed bronch (>48 hours after diagnosis). The patients with early bronch were sicker, with higher rate of ICU admission (42% vs. 0% in late group) and in-hospital mortality (25% vs. 8% in late group). However, those patients who underwent bronch later had a higher rate of 30-day re-admission (33% vs. 22% in early group).

Conclusion

Bronchoscopy/BAL was the best diagnostic test in patients with AL and CT-confirmed pneumonia, even though it was only performed in 48% of patients. Early bronchoscopy (first 48 hs) has better diagnostic yield than late bronchoscopy (>48 hs), directing the antimicrobial therapy on these patients (based on the identification of bacteria, fungus or viruses), and decreasing the 30-day re-admission rate.

Disclosures

J. Adachi, Merck: Grant Investigator, Research grant.

1570. Infectious Disease (ID) Complications in Immunocompromised (IC) Patients with Cancer Post-Hurricane Harvey at a Comprehensive Cancer Center in 2017

Background

During 2017, Houston had the most destructive flood-related disaster in recent history due to Hurricane Harvey. Afterward, educational material with information of possible ID problems was provided to all healthcare workers.

Methods

Prospective surveillance of flood-related ID complications in IC cancer patients. During the 60 days post-Harvey, we monitored referrals to the ID service at MDA Cancer Center. We used the following definitions: Type of exposure: direct to flood water, direct to flooded structures, and others indirect (i.e., prophylaxis). Association risk: “Yes” (direct exposure), “No” (asymptomatic, no exposure, or infection noted prior) and “Probable” (lack of records to establish correlation). Types of infections were classified as soft tissue, gastrointestinal, respiratory, IV line associated or fever. Recommendations were noted including types of antibiotics, vaccinations, or imaging.

Results

A total of 36 cases were referred to our department. Fifty-six percent had exposure to flood-water with/without exposure to structures, 33% to structures only and 11% were other (Figure 1). Regarding the association of an ID problem to flood-exposure, we found an equal distribution of 39% with an association and 39% with a probable association, and the remaining 22% with no association (Figure 2). Of the infections, the majority of infections were respiratory (42%) or soft tissue (31%) (Figure 3). There was a trend of broader antimicrobial coverage for water associated bacteria and mold infections. Only six immunizations recommendations were attained.

Conclusion

To our knowledge this is the first and largest study of ID complications in IC cancer patients following a natural disaster in medical literature. Our active surveillance showed a lower number of disaster related ID complications than anticipated, possibly because of difficulty determining exposure and underreporting of infections despite active education. Due to individual immunosuppression and exposure, there was variety of recommendations (antimicrobials, studies, or vaccinations). In the event of a weather disaster, we are developing a standard triage survey regarding type of exposure and impact, and also a process for effective immunizations.

Disclosures

J. Adachi, Merck: Grant Investigator, Research grant

1786. Safety, Efficacy, and Clinical Impact of Penicillin Allergy Skin Testing in Immunocompromised Cancer Patients at a Comprehensive Cancer Center

Background

Patients reporting penicillin (PCN) allergies often receive alternative antibiotic therapy associated with significant health and economic disadvantages. The use of penicillin allergy skin testing (PST) to rule out PCN allergies is safe and effective in immunocompetent patients, yet data in immunocompromised patients are limited.

Methods

A quality improvement process using PST to clarify PCN allergies and guide antibiotic therapy was implemented at MD Anderson Cancer Center (April–October 2017). Patients admitted to Leukemia and Genitourinary Medical Oncology (GUMO) services with a history of Type 1 reactions to PCN were eligible.

Results

A total of 218 consecutive patients with reported PCN allergies were screened; 100 met inclusion criteria, were consented, and underwent PST (67 Leukemia, 33 GUMO). Sixty-one percent of tested patients reported cutaneous reactions, and 79% reported reactions >20 years ago. The most common reported allergy was to penicillin V/G (64%). Forty-eight percent were on steroids and 49% were on immunosuppresive therapy at the time of PST. For leukemia patients the median absolute neutrophil count was 0.78 (0–64.88 K/μL) and absolute lymphocyte count was 0.81 (0–116.71 K/μL). Ninety-five percent patients tested negative for PCN allergy and 4% were positive (three Leukemia, one GUMO). One test was indeterminate (negative histamine control). After PST, 25 of 67 (37%) patients receiving antibiotic therapy were changed to PCN-based antibiotics (PBA) (Figure 1). During the follow-up period (median: 177; range: 3–316 days), 65 patients who tested negative were readmitted (total 185 readmissions) and PBAs were prescribed in 58 of those readmissions (Figure 2). The most common indications for PBAs included neutropenic fever, pneumonia, and bacteremia. No patients given PBAs after negative PST experienced allergic reactions.

Conclusion

PST is safe and effective to rule out PCN allergies in immunocompromised patients, with 95% of patients testing negative for PCN allergy, suggesting that patient-reported allergy is unreliable. The rate of negative tests is comparable to data in immunocompetent patients. The use of PST in cancer patients allows for optimization of antimicrobial therapy and stewardship, which is vital in this patient population at increased risk for infections and infectious complications.

Disclosures

M. Taremi, ALK-Abello: Educational grant recipient, Educational grant.

Multicenter Evaluation of Ceftolozane/Tazobactam for Serious Infections Caused by Carbapenem-Resistant Pseudomonas aeruginosa

A multicenter, retrospective study of patients infected with carbapenem-resistant Pseudomonas aeruginosa who were treated with ceftolozane/tazobactam was performed. Among 35 patients, pneumonia was the most common indication and treatment was successful in 26 (74%). Treatment failure was observed in all cases where isolates demonstrated ceftolozane-tazobactam minimum inhibitory concentrations ≥8 μg/mL.

Improvement in the diagnosis of catheter-related bloodstream infections in a tertiary cancer center

BACKGROUND

Identifying a central venous catheter (CVC) as the source of bacteremia requires drawing simultaneous blood cultures (BCs) from the CVC and peripheral site and correct labeling of the BC source. In our emergency center (EC), 52% of BCs collected from febrile cancer patients lacked source information, making the diagnosis and management of catheter-related bloodstream infections (CRBSIs) challenging.

METHODS

Between January 2015 and June 2015, we conducted a quality improvement project in our EC aiming to increase the occurrence of simultaneous BC drawing with accurate source labeling by 10%.

RESULTS

Staff education and monitoring increased average BC source labeling from a baseline of 48% to a much better rate of 70%. Label introduction led to increased source labeling to 94% by June 2015. This project had a significant influence in patients with a CVC and a positive BC because the physician is now able to determine whether the CVC is the source of the bacteremia in 88% of cases compared with 36% at baseline (P = .0003).

CONCLUSIONS

Education without an active intervention is usually not enough. Simple solutions such as label introduction can have significant influence on patient safety and care. Accurate diagnosis may guide clinicians at the bedside to appropriately manage CVCs in the setting of bacteremia, remove a CVC when indicated, and prevent unnecessary CVC removal with its potential safety and cost-effectiveness implications.

Influence of Minimum Inhibitory Concentration in Clinical Outcomes of Enterococcus faecium Bacteremia Treated With Daptomycin: Is it Time to Change the Breakpoint?

BACKGROUND

Daptomycin has become a front-line antibiotic for multidrug-resistant Enterococcus faecium bloodstream infections (BSIs). We previously showed that E. faecium strains with daptomycin minimum inhibitory concentrations (MICs) in the higher end of susceptibility frequently harbor mutations associated with daptomycin resistance. We postulate that patients with E. faecium BSIs exhibiting daptomycin MICs of 3-4 µg/mL treated with daptomycin are more likely to have worse clinical outcomes than those exhibiting daptomycin MICs ≤2 µg/mL.

METHODS

We conducted a multicenter retrospective cohort study that included adult patients with E. faecium BSI for whom initial isolates, follow-up blood culture data, and daptomycin administration data were available. A central laboratory performed standardized daptomycin MIC testing for all isolates. The primary outcome was microbiologic failure, defined as clearance of bacteremia ≥4 days after the index blood culture. The secondary outcome was all-cause in-hospital mortality.

RESULTS

A total of 62 patients were included. Thirty-one patients were infected with isolates that exhibited daptomycin MICs of 3-4 µg/mL. Overall, 34 patients had microbiologic failure and 25 died during hospitalization. In a multivariate logistic regression model, daptomycin MICs of 3-4 µg/mL (odds ratio [OR], 4.7 [1.37-16.12]; P = .014) and immunosuppression (OR, 5.32 [1.20-23.54]; P = .028) were significantly associated with microbiologic failure. Initial daptomycin dose of ≥8 mg/kg was not significantly associated with evaluated outcomes.

CONCLUSIONS

Daptomycin MICs of 3-4 µg/mL in the initial E. faecium blood isolate predicted microbiological failure of daptomycin therapy, suggesting that modification in the daptomycin breakpoint for enterococci should be considered.

Antibiotic-resistant gram-negative bacterial infections in patients with cancer

Patients with cancer are at high risk for infections caused by antibiotic resistant gram-negative bacteria. In this review, we summarize trends among the major pathogens and clinical syndromes associated with antibiotic resistant gram-negative bacterial infection in patients with malignancy, with special attention to carbapenem and expanded-spectrum β-lactam resistance in Escherichia coli, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Stenotrophomonas maltophilia--all major threats to our cancer patients. Optimal therapy for these antibiotic-resistant pathogens still remains to be determined.

Antidepressant use and 10-year incident fracture risk: the population-based Canadian Multicentre Osteoporosis Study (CaMoS)

We used data from a large, prospective Canadian cohort to assess the association between selective serotonin reuptake inhibitors (SSRIs) and serotonin and noradrenaline reuptake inhibitors (SNRIs) and fracture. We found an increased risk of fractures in individuals who used SSRI or SNRI, even after controlling for multiple risk factors.

INTRODUCTION

Previous studies have suggested an association between SSRIs and increasing risk of fragility fractures. However, the majority of these studies were not long-term analyses or were performed using administrative data and, thus, could not fully control for potential confounders. We sought to determine whether the use of SSRIs and SNRIs is associated with increased risk of fragility fracture, in adults aged 50 + .

METHODS

We used data from the Canadian Multicentre Osteoporosis Study (CaMos), a prospective randomly selected population-based community cohort; our analyses focused on subjects aged 50+. Time to event methodology was used to assess the association between SSRI/SNRI use, modeled time-dependently, and fragility fracture.

RESULTS

Among 6,645 subjects, 192 (2.9%) were using SSRIs or/and SNRIs at baseline. During the 10-year study period, 978 (14.7%) participants experienced at least one fragility fracture. In our main analysis, SSRI/SNRI use was associated with increased risk of fragility fracture (hazard ratio (HR), 1.88; 95% confidence intervals (CI), 1.48-2.39). After controlling for multiple risk factors, including Charlson score, previous falls, and bone mineral density hip and lumbar bone density, the adjusted HR for current SSRI/SNRI use remained elevated (HR, 1.68; 95% CI, 1.32-2.14).

CONCLUSIONS

Our results lend additional support to an association between SSRI/SNRI use and fragility fractures. Given the high prevalence of antidepressants use, and the impact of fractures on health, our findings may have a significant clinical impact.

Angular correlation between B K-VV Auger electrons of BF3 molecules and coincident fragment ions: manifestation of the difference between the angular correlation and molecular frame Auger electron angular distribution

We have measured the angular correlation between the B K-VV Auger electrons of BF(3) molecules and the coincident fragment-ion pairs of BF(2)(+)-F(+). Then, we have found that the measured angular correlation patterns depending on the mutual angle between the light polarization direction and molecular orientation are affected by the anisotropic axis distribution of the molecular ensemble of BF(3)(+) reflecting the anisotropic nature of photon-molecule interaction. In this context, we have pointed out generally that for coincidence experiments, so-called molecular frame Auger electron angular distributions are realized only if the axis distribution of the molecular ion ensemble is isotropic.

Growth suppression of non-small cell lung carcinoma cells by the introduction of the p16(INK4A) gene

The p16(INK4A) gene is frequently inactivated in nonsmall cell lung carcinoma (NSCLC) by either mutations, deletions or DNA methylations. To assess the biological significance of p16(INK4A) inactivation in the development of NSCLC, full-length p16(INK4A) cDNA was introduced into NSCLC cell lines, A549 and H322, in which p16(INK4A) was homozygously deleted. NSCLC cells transfected with the p16(INK4A) expression vector formed colonies in 20-68% of those with a control vector, and exogenous p16(INK4A) protein was expressed in 4 of 68 A549-derived clones and none of 29 H322-derived clones, respectively. A549-derived clones which stably expressed the exogenous p16(INK4A) gene showed significant decrease in growth rate in vitro and tumorigenicity in vivo in proportion to the level of p16(INK4A) expression. Furthermore, the cell cycle of these cells significantly delayed with accumulation of cells in G1 phase. Micro-injection of p16(INK4A) expression vector also revealed that p16(INK4A) blocked S phase entry in both A549 and H322 cells. These results suggest that the restoration of the p16(INK4A) function suppresses the growth of NSCLC cells by induction of G1 arrest in the cells. Therefore, inactivation of p16(INK4A) may play an important role in the enhancement of unregulated NSCLC growth in vivo.

Frailty and sarcopenia: definitions and outcome parameters

An operational definition of musculoskeletal decline in older people is needed to allow development of interventions for prevention or treatment, as was developed for the treatment of osteoporosis. Frailty and sarcopenia are linked, but distinct, correlates of musculoskeletal aging that have many causes, including age-related changes in body composition, inflammation, and hormonal imbalance. With the emergence of a number of exciting candidate therapies to retard the loss of muscle mass with aging, the derivation of a consensual definition of sarcopenia and physical frailty becomes an urgent priority. Although several consensual definitions have been proposed, these require clinical validation. An operational definition, which might provide a threshold for treatment/trial inclusion, should incorporate a loss of muscle mass as well as evidence of a decrease in muscle strength and/or physical activity. Evidence is required for a link between improvements in the measures of muscle strength and/or physical activity and clinical outcomes to allow development of interventions to improve clinical outcomes in frail older patients.

Association between timing of zoledronic acid infusion and hip fracture healing

Patients in the Health Outcomes and Reduced Incidence with Zoledronic Acid Once Yearly (HORIZON) Recurrent Fracture Trial were assessed for evidence of delayed hip fracture healing. No association was observed between zoledronic acid (ZOL) and delayed healing. We conclude that ZOL has no clinically evident effect on fracture healing, even when the drug is infused in the immediate postoperative period.

INTRODUCTION

Intravenous zoledronic acid 5 mg (ZOL) given after a hip fracture reduces secondary fracture rates and mortality. It has been postulated that bisphosphonates may affect healing if given soon after a fracture. We sought to determine whether the timing of ZOL infusion affected the risk of delayed hip fracture healing.

METHODS

In the HORIZON Recurrent Fracture Trial, patients were randomized within 90 days of a low-trauma hip fracture to receive either once-yearly ZOL (n = 1,065) or placebo (n = 1,062). Clinical symptoms of delayed hip fracture healing were sought at randomization, 6 months and 12 months after fracture; if present, a central adjudication committee blinded to treatment assignment reviewed radiographs and clinical records. Median follow-up was 1.9 years.

RESULTS

The overall incidence of delayed healing was 3.2% (ZOL) and 2.7% (placebo; odds ratio [OR], 1.17; 95% confidence interval [CI], 0.72-1.90; p = 0.61). Logistic regression models revealed no association between ZOL and delayed healing even after adjusting for other risk factors (OR, 1.21; 95% CI, 0.74-1.99; p = 0.44). There was no interaction by timing of infusion, and nonunion rates were similar even when ZOL was given within 2 weeks of hip fracture repair. NSAID use was significantly associated with delayed fracture healing (OR, 2.55; 95% CI, 1.49-4.39; p < 0.001).

CONCLUSIONS

ZOL has no clinically evident effect on fracture healing, even when the drug is infused in the immediate postoperative period.

Serratia marcescens bacteremia because of contaminated prefilled heparin and saline syringes: a multi-state report

A national outbreak of Serratia marcescens bacteremia because of contaminated prefilled heparin and saline syringes led to their recall. We evaluated the clinical impact of this outbreak in 57 patients at 3 centers. All patients were symptomatic and were treated with intravenous antibiotics with a fatal outcome in 1 patient.

Dissemination of methicillin-resistant Staphylococcus aureus USA300 sequence type 8 lineage in Latin America

BACKGROUND

Methicillin-resistant Staphylococus aureus (MRSA) is an important nosocomial and community-associated (CA) pathogen. Recently, a variant of the MRSA USA300 clone emerged and disseminated in South America, causing important clinical problems.

METHODS

S. aureus isolates were prospectively collected (2006-2008) from 32 tertiary hospitals in Colombia, Ecuador, Peru, and Venezuela. MRSA isolates were subjected to antimicrobial susceptibility testing and pulsed-field gel electrophoresis and were categorized as health care-associated (HA)-like or CA-like clones on the basis of genotypic characteristics and detection of genes encoding Panton-Valentine leukocidin and staphylococcal cassette chromosome (SCC) mec IV. In addition, multilocus sequence typing of representative isolates of each major CA-MRSA pulsotype was performed, and the presence of USA300-associated toxins and the arcA gene was investigated for all isolates categorized as CA-MRSA.

RESULTS

A total of 1570 S. aureus were included; 651 were MRSA (41%)--with the highest rate of MRSA isolation in Peru (62%) and the lowest in Venezuela (26%)--and 71%, 27%, and 2% were classified as HA-like, CA-like, and non-CA/HA-like clones, respectively. Only 9 MRSA isolates were confirmed to have reduced susceptibility to glycopeptides (glycopeptide-intermediate S. aureus phenotype). The most common pulsotype (designated ComA) among the CA-like MRSA strains was found in 96% of isolates, with the majority (81%) having a < or =6-band difference with the USA300-0114 strain. Representative isolates of this clone were sequence type 8; however, unlike the USA300-0114 strain, they harbored a different SCCmec IV subtype and lacked arcA (an indicator of the arginine catabolic mobile element).

CONCLUSION

A variant CA-MRSA USA300 clone has become established in South America and, in some countries, is endemic in hospital settings.

The role of vitamin B6 in the prevention of haematological toxic effects of linezolid in patients with cancer

BACKGROUND

Linezolid is the first approved synthetic oxazolidinone with activity against multidrug-resistant gram-positive pathogens. However, haematological toxic effects of linezolid frequently limit its prolonged use, especially in patients with poor marrow reserves such as those with cancer receiving chemotherapy. Previous authors have reported that administration of vitamin B6 with linezolid reversed pancytopenia in two patients.

METHODS

This is an open-label study of 31 patients with cancer who received linezolid at 600 mg twice daily and vitamin B6 at 50 mg/day for at least 2 weeks mean therapy duration and they were matched to 62 control patients who received linezolid without vitamin B6 to determine whether the concomitant use of vitamin B6 attenuates the haematological toxicity of linezolid in patients with cancer.

RESULTS

Patients were matched according to age, underlying disease, duration of therapy, creatinine level and use of chemotherapy. We found no significant differences in the rate of haematological toxic effects between the two patient groups. The rate of thrombocytopenia was 13% in the vitamin B6 group and 15% in the control group (P = 0.82). Also, the rate of leucopenia was 7% versus 5%, respectively (P = 0.75). None of the patients in the vitamin B6 group had anaemia compared with 5% in the control group.

CONCLUSIONS

Vitamin B6 given at 50 mg/day may have an impact on anaemia but did not prevent linezolid-induced thrombocytopenia or leucopenia in cancer patients.