Friday, December 23, 2016 Written by Dr. David Persing, Chief Medical and Technology Officer, and Dr. Fred Weir, Director of Research and Development

Industry Q&A - Inside Cepheid Innovation: Women’s Health Portfolio

Dr. David Persing and Dr. Fred Weir discuss the development of Xpert CT/NG, GBS LB and why these recently introduced tests are an important step in Cepheid’s plans for a complete line of Women’s Health diagnostic tests

Q: Why did you select a test for Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) as the first STD product to develop for Cepheid’s family of Women’s Health Products and how is the Introduction of Xpert CT/NG significant?

Dave Persing: Chlamydia and Gonorrhea are the most common sexually transmitted bacterial infections in the United States. Both are easily treated when detected and managed quickly. Yet, less than 40 percent of sexually active women under age 25 were tested for chlamydia last year.

Fred Weir: There were already good products on the market, but they were batch-based systems that require a minimum number of samples to begin and could only be run in high-complexity labs. These were not a good fit for clinicians or patients requiring faster time to results. Turn-around time of less than 90 minutes can be especially important for patients presenting in Emergency Departments and for clinicians managing patients who may not return for treatment. Our goal was to develop a test that would help clinicians intercept these common infections at the earliest stage possible.

Q: False Positives have been an issue with other STD diagnostic tests, especially Gonorrhea. How did your research team improve Xpert CT/NG’s specificity?

Dave Persing: From our unique experience with the biothreat detection program, where more than 11 million tests have been performed with no false positives, our research team has learned that the best way to minimize false positive results is to include more than one genetic target. In addition, our research team used in silico approaches to uncover multiple genomic targets for improving the accuracy of both CT and NG detection.

Fred Weir: Xpert CT/NG has two unique and independent targets to identify gonorrhea in a patient sample; both targets have to be positive at the same time for the patient to be considered infected.

Q: What are some of the other unique features that differentiate the Xpert CT/NG test from others on the market?

Dave Persing: First, unlike some of the other recent products, Xpert CT/NG has been cleared for use with all the major sample types: male and female urine, endocervical swabs and self-collected vaginal swabs collected in a clinical setting. Second, we included a first-in-class sample adequacy control that we believe overcomes limitations of first-generation technologies and adds significantly to the interpretation of diagnostic results generated by the GeneXpert System.

Fred Weir: Xpert CT/NG is the most sophisticated test in its class, yet it can be performed on-demand by virtually any laboratory, to maximize the medical impact of the results. We are hoping that the assay has significant impact on reducing the burden of disease.

Q: Moving to the whole women’s health portfolio: Xpert GBS was the first test Cepheid introduced in the Women’s Health Portfolio. What are the benefits of the newly introduced Xpert GBS LB?

Fred Weir: Xpert GBS is the first and only molecular test designed to be run both in the clinical lab and near-patient by non-laboratory professionals such as labor and delivery nurses — 24 hours a day, 365 days a year. Xpert GBS LB, for antepartum screening, is designed for use in the clinical lab. It allows users to simply perform ONE easy step and the GeneXpert System does the rest.

Dave Persing: With the Introduction of Xpert GBS LB, Cepheid is the only manufacturer to offer clinicians a complete GBS testing solution on a single platform. The current standard of care for prevention of neonatal GBS disease is screening expectant mothers at 35-37 weeks of gestation using enriched broth techniques (such as LimBroth) after 18-24 hours of incubation, followed by culture methods which can add an additional day of incubation and analysis from a highly skilled technician. The GeneXpert System, with Xpert GBS LB and Xpert GBS, is the only solution that fully meets CDC criteria for both antenatal and intrapartum testing.

For a technical animation of how the GeneXpert cartridge works, visit