NEW YORK (GenomeWeb) – Startup Enable Biosciences announced last week it has received two Phase I Small Business Innovation Research grants to further develop applications for a highly sensitive technique that uses PCR to detect antibodies.
The core technology of the Menlo Park-based firm is called antibody detection by agglutination-PCR, or ADAP, as previously described. Initially developed at Stanford University, the method involves chemically conjugating PCR-incompetent half-amplicons to an antigen, with single-stranded DNA brought close enough together for qPCR when the antigen interacts with antibodies in a patient sample.
The new funding totals about $500,000 and provides support for about 10 months, the firm's CSO Peter Robinson told GenomeWeb in an interview.
Because the ADAP method uses PCR, instead of a more typical ELISA or a chemiluminescent readout to detect host antibodies, it is 1,000- to 10,000-fold more sensitive than standard techniques, Robinson said, providing advantages for early detection of disease. Other tests of patient immune response are often currently radio-immunoassays, which necessitate off-site testing using radio isotopes thus increasing turnaround time. ADAP-based tests would potentially be faster and could also be multiplexed using barcoding technologies, Robinson said, further expanding their utility.
One of the SBIRs, awarded by the National Institutes of Diabetes and Digestive and Kidney Diseases, is focused on developing an assay for type I diabetes. That funding will also be used to continue to validate the firm's technology and to make sure that the work done in the lab holds up in a clinical setting, Robinson said, namely by testing patient samples that have been validated with other diagnostic technologies and demonstrating equivalence.
The NIDDK grant also funds a retrospective analysis of longitudinal samples collected from patients well before they became diabetic, to see if the firm's test has the power to detect disease earlier than other diagnostic methods.
"Our test is around 1,000 times more sensitive than ones that are currently being used, so our theory is that we can pick up on the [diabetes] biomarkers at a much earlier stage, when they're at very low levels in the bloodstream," Robinson said.
For this aspect of the project Enable has been accessing a biorepository at the Benaroya Institute in Seattle, he said, and the firm already has some pilot data.
The second SBIR, from the National Science Foundation, funds research and technology development particularly aimed at creating a highly multiplexed version of the ADAP technology.
"Fundamentally, our technology is based on a DNA barcoding mechanism, so we can encode the identities of many different biomarkers by using different sequences that we attach to the antigen substrate," explained Robinson. The NSF grant will fund the creation of panels of between 20 and 100 separate biomarkers.
Robinson envisions research applications, for scientists interested in studying the immune response in different diseases and biomarker discovery, as well as development of advanced diagnostics. For the latter, there could be many clinically relevant biomarkers included in a panel, which would all be quantified with a single step.
The company is still working out the detection format for multiplexed assays. It is currently using PCR but is considering other platforms, such as Nanostring's digital gene expression analysis technology, digital PCR, and . "We think there could be a lot of synergy with our technology," Robinson said, adding that next-generation sequencing technologies using "Illumina-style barcoding" could also work with Enable's system.
In addition to the SBIR funding, Enable also recently won the Northern California regional section of the 2016 Harvard Business School New Ventures competition, and was a top four finalist for the global competition.
The firm's first commercialized product will likely be a lab-developed test, run either by Enable or by a hospital lab with Enable providing reagents in exchange for a percentage of reimbursement, Robinson said.
A more advanced incarnation the firm is considering is a point-of-care test, although this would require a platform and is a longer-term goal, Robinson noted.
In terms of competition, there are lab-developed and commercially available autoantibody tests available for type I diabetes, particularly a zinc transporter 8 autoantibody test from Kronus that was authorized for marketing by the US Food and Drug Administration in 2014. A firm called Islet Bioscience is also commercializing an early diabetes diagnostic that examines methylation of cell-free DNA using digital PCR. But Enable's test might have an advantage in terms of sensitivity and multiplexing capability.
The highly multiplexed test may also fall into a research market, so competition could come from protein microarrays marketed by companies like Promega and Thermo Fisher Scientific. Sensitivity could be an advantage here as well.
Enable has a provisional US patent, has filed an international one, and is in the process of filing a few more in the US as well, Robinson said.
The company has had early-stage conversations with a few other firms, and is further pursuing collaborations and joint development projects in industry and academia. The NIDDK grant is a joint effort between Enable and the Madison Clinic for Pediatric Diabetes at UCSF, Robinson said, and the NSF grant is a collaboration with a professor of immunology at Stanford University School of Medicine.
"At this time we don't have any corporate collaborations, so we are interested in finding connections," he said.