New Data Show Karius Test Improves Pathogen Detection In Challenging Patient Populations

Published: Oct 04, 2017

– Karius Presenting New Data From Five Abstracts at Infectious Disease Week Annual Meeting

– SEP-SEQ Trial Demonstrates the Karius Test’s Ability to Rapidly Identify a Broad Range of Pathogens in Septic Patients With a Single Blood Draw –

REDWOOD CITY, Calif. & SAN DIEGO--(BUSINESS WIRE)--Karius, Inc., a life sciences company focused on conquering infectious diseases, today announced several presentations that demonstrate the ability of the Karius Digital CultureTM Test to rapidly and accurately identify pathogens in patients with sepsis, bloodstream infections, neutropenic fever, who are immunocompromised, or have rare infections such as Mycobacterium chimaera. Data from the five studies are being presented at the Infectious Diseases Society of America’s IDWeek 2017 conference in San Diego.

“These studies evaluated the Karius test in some of the most challenging to diagnose infections patients may face, including sepsis, bloodstream infections, and opportunistic infections in immunocompromised patients, among others”

“These studies evaluated the Karius test in some of the most challenging to diagnose infections patients may face, including sepsis, bloodstream infections, and opportunistic infections in immunocompromised patients, among others,” said Mickey Kertesz, Ph.D., Chief Executive Officer of Karius. “We are pleased to share more evidence with the clinical community demonstrating the utility of the Karius test in broad areas of unmet need, by arming physicians with a single test that can quickly deliver a potentially life-saving diagnosis, often times much faster than traditional testing methods in situations where time is critical.”

“There is a clear need for diagnostic tests that accurately identify a breadth of potential pathogens to inform more effective therapy,” said David Hong, M.D., Medical Director at Karius, and co-author of the SEP-SEQ study. “This is especially true for sepsis, since in about 40 percent of cases a causative pathogen is never identified. The results of our trial show the Karius test can identify a broad range of pathogens in patients with sepsis from a single blood draw, nearly three times more often than blood culture and more often than all microbiology tests combined. These benefits demonstrate the potential for the test to become a standard of care in identifying pathogens in sepsis and other challenging infections.”

The following studies, presented at IDWeek 2017, demonstrate the potential of the Karius test as a broad and rapid method for clinical diagnosis of infectious disease:

The SEP-SEQ Trial - Clinical Validation of the Karius Plasma Next-Generation Sequencing Test for Pathogen Detection in Sepsis (Late-breaking oral session, LB-5): Presented by Simone Thair, Ph.D., a postdoctoral scholar at the Stanford University School of Medicine

In this study, blood samples were taken from patients presenting in the emergency department with sepsis and the Karius test was performed. Results of the test were then compared to initial blood cultures and subsequent microbial tests. The study has enrolled 350 patients, and the Karius test identified potential pathogens in 60% of patients (210 of 350). The results showed a high correlation with standard microbiology methods (99/131). In contrast, 18% of patients (63 of 350) had a positive initial blood culture and 37.4% of patients (131/350) had a potential infectious etiology identified using a composite microbiology laboratory standard. After subjects were evaluated by an independent clinical adjudication committee, 86.7% (182/210) of the Karius test results were judged to be consistent with a potential cause of the septic event.

Performance of the Karius Plasma Next Generation Sequencing Test in Determining the Etiologic Diagnosis of Febrile Neutropenia (Poster #2084): Presented by Esther Benamu, M.D., University of Colorado, Denver

This study evaluated 32 patients with chemotherapy-induced neutropenic fever (NF), including 13 receiving antibiotics and 5 receiving antifungals, and compared blood culture (BC) results to results from the Karius test. Compared to BC, the Karius test positive agreement was 100% (5/5). In addition, the Karius test detected organisms in 18 of 27 patients with negative BC. In 16 of these 18 cases (89%), the detected organisms were deemed probable or possible pathogens after clinical adjudication by 3 infectious disease specialists. In one sample, Aspergillus fumigatus was detected in a patient with new lung nodules.

The results of this study show the potential of the Karius test to detect a breadth of pathogens in the setting of NF, even when patients are pretreated with antibiotics.

Direct Detection and Quantification of Bacterial Cell-free DNA in Patients with Bloodstream Infection (BSI) Using the Karius Plasma Next Generation Sequencing (NGS) Test (Poster #2083): Presented by Lisa Wanda, Duke University

This study prospectively enrolled 108 patients, 73 with culture confirmed BSI due to Staphylococcus aureus (36) or Gram-negative bacilli (37), and 35 with negative blood cultures. Blood samples were collected for the Karius test within one day of positive blood culture and then every two-to-three days. When compared to baseline blood culture, the Karius test had positive agreement of 74% (54/73) and negative agreement of 77% (27/35). Serially collected samples were positive by the Karius test significantly longer than blood culture (mean 6.5 days vs. 3.4 days, respectively).

The Karius test can directly detect pathogens in patients with BSI and remains positive significantly longer than blood culture. These characteristics can be useful in the diagnosis and monitoring of infections, particularly in those with sterile blood cultures.

Rapid Detection of Invasive Mycobacterium chimaera Infection by Using a Novel Plasma-Based Next-Generation Sequencing Assay (Poster #458): Presented by Jim Nomura, M.D., Kaiser Permanente, Los Angeles

Clusters of Mycobacterium chimaera (M. chimaera) infection have been linked to contaminated heater-cooler devices used during cardiac surgery; however, diagnosis is difficult due to the poor sensitivity and slow growth of standard acid-fast bacilli (AFB) cultures.

This case series compared the Karius test and AFB culture for the detection of M. chimaera among patients who had a cardiac surgery performed at a Southern California hospital with known exposure risk. Of the seven confirmed M. chimaera cases, six had invasive disease and one had a localized wound infection. The Karius test detected M. chimaera in 83% with invasive disease (5 of 6) in a median of 5 days. In comparison, AFB cultures were positive in a median of 20 days; whereas speciation to M.chimaera required a median of 42 days from specimen collection.

This is the first reported detection of M.chimaera using a plasma-based NGS assay, which identified M.chimaera approximately 15 days sooner than AFB culture positivity and 37 days sooner than speciation from AFB culture.

The DISCOVER Trial: Application of the Karius Plasma Next-Generation Sequencing Test for Pathogen Detection in Stem-Cell Transplant Patients (Poster #2093): Presented by Monica Fung, M.D., University of California, San Francisco (UCSF)

This study prospectively enrolled 20 stem-cell transplant (SCT) patients to evaluate the Karius test for the monitoring and diagnosis of infections over time. Patients had blood drawn for the Karius test prior to SCT, at regular intervals after transplant, and at onset of fever episodes.

Results from the Karius test were then compared to the results obtained by conventional microbiologic tests. When compared to a conventional cytomegalovirus test (CMV qPCR), the Karius test showed 100% (26 of 26) correlation with results above the lower limit of quantitation for qPCR. The Karius test was also able to detect Staphylococcus aureus prior to blood culture and Chlamydia trachomatis a full 30 days prior to diagnosis by a targeted assay.

This pilot study demonstrates that the Karius test can identify co-pathogens in SCT patients. The use of the Karius test to monitor SCT patients for infection could result in earlier detection of pathogens, enabling earlier targeted therapy for this vulnerable population.

About the Karius Digital Culture™ Test

The Karius Digital Culture Test uses Next-Generation Sequencing (NGS) and analytics for the broad and rapid detection of microbial cell-free DNA through a standard blood draw. Unlike conventional culture and panel testing methods that test for a narrow range of pathogens, the Karius test can detect more than 1,250 pathogens including bacteria, DNA viruses, and eukaryotic organisms such as yeasts, molds, and protozoa. Results are typically available within one business day of sample receipt. See the full list of microorganisms detected by Karius. Through Karius’ CAP-accredited and CLIA-certified laboratory service, the test empowers doctors to diagnose infections quickly while sparing patients the pain and risk of invasive biopsies, and provide rapid and more targeted treatment.

About Karius, Inc.

Karius is a life sciences company focused on conquering infectious diseases through the innovative use of next-generation sequencing to analyze microbial cell-free DNA. The company’s genomics platform delivers unprecedented insight into the microbial landscape, providing clinicians with a comprehensive test capable of identifying more than 1,250 pathogens directly from blood and helping industry accelerate drug development. For more information visit kariusdx.com and follow us on Twitter at @kariusdx.

Contacts

Karius, Inc.
Kelli Kampanis, 310-625-3248
media@kariusdx.com
Jessica Volchok, 310-849-7985
media@kariusdx.com

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