Point-of-care immunoassay for early diagnosis of pertussis

Period of Performance: 06/21/2016 - 05/31/2017

$407K

Phase 2 SBIR

Recipient Firm

Dxdiscovery, Inc.
RENO, NV 89557
Principal Investigator
Principal Investigator

Abstract

Project SummaryPertussis is rapidly re-emerging as a serious public health threat in the United States. Despite high vaccinecoverage nationally, annual reported cases in the U.S. have been increasing recently, with a 57-year high of48,000 in 2012. Moreover, reported cases represent a large underestimate of pertussis infections. Diagnosis ofearly pertussis (catarrhal stage; prior to paroxysmal cough) is particularly challenging because its symptomsare non-specific and because there are no assays that can diagnose pertussis at the point of patient care.There is a critical need to develop improved pertussis diagnostics to fill this gap because pertussis treatmentreduces disease severity and duration, but only if treatment begins prior to paroxysmal cough.The goal of this project is to develop a rapid (<15min), point-of-care (POC) immunoassay to detect Bordetellapertussis during early disease. The target population will be infants with the non-specific, respiratory tractinfection symptoms of early-stage pertussis. The approach will be detection of B. pertussis antigens fromnasopharyngeal (NP) samples by lateral flow immunoassay (LFI). The POC diagnostic that we propose isinnovative because it will change the current clinical status quo: a pertussis LFI will give healthcare providersimmediate access to actionable and relevant information, which will enable rapid and appropriate patient care.In Phase I, we demonstrated the feasibility of our LFI approach and achieved every milestone of our Phase ISpecific Aims. Specifically, we used an innovative bioinformatics-based strategy to develop epitope-specificpolyclonal antibodies (pAbs) against a B. pertussis antigen that has both cell-associated and secretedisoforms. We then validated our pAbs for reactivity with both isoforms in sensitive and specific LFI prototypes.The limit of detection of our current pAb-based LFI is 1.6 x 105 CFU, which is well below the typical bacterialburden of infant NP washes (107 to 1010 CFU/ml) or swabs (106 CFU).In Phase II, we will build on our Phase I results and develop an advanced monoclonal antibody (mAb) basedLFI commercial diagnostic. We will focus on developing mAbs against the validated biomarker epitopes (Aim 1)and incorporating these mAbs into an LFI with sensitivity and commercialization potential superior to that of thePhase I pAb-based prototypes. We will i) optimize the mAb-based LFI for analytical sensitivity in NP samples(Aim 2), ii) determine clinical sensitivity and specificity at different disease stages in a clinically relevant,baboon infection model (Aim 3), and iii) determine the LFI's limit of detection with patient samples (Aim 4).Together, this data will guide our FDA 510(k) Pre-Submission at the end of Phase II. Successful completion ofour milestones will ultimately yield a rapid, affordable, POC immunoassay that will dramatically increase earlypertussis diagnosis, which will i) initiate prompt treatment, ii) reduce disease severity and duration, iii) limitoutbreaks by preventing unnecessary transmission, and iv) save infant lives.