NEW YORK – Immune mapping firm Serimmune has put the bulk of its previous research efforts on hold and shifted focus to aiding development of tests and vaccines for SARS-CoV-2.
The Goleta, California-based company combines next-generation sequencing with massive random peptide libraries to profile patient immune responses as part of research into diagnostic and therapeutic development for a variety of conditions including autoimmune diseases, cancers, and infectious disease.
Last week it announced that it had received a research milestone payment from Merck, which is an investor in the company, for work on the drugmaker's preclinical efforts in infectious disease.
Much of this and the company's other work is now on pause, though, said CEO Noah Nasser, as it looks to apply its platform to the ongoing COVID-19 pandemic.
"About six week ago, we put most of [the company's ongoing work] on hold, because we looked at COVID-19 and said, 'We think this is something we can contribute to at a high level,' and it's probably the most critical thing that we could do over the course of the next six months both to prove out how valuable our technology is and also to contribute clinically to a disease state that has been truly transformative to the US and globally," he said.
Serimmune's immune mapping platform uses bacterial display to express and display massive libraries of unique peptide sequences (1010 unique sequences). Samples of interest such as serum or saliva are then screened against these libraries, with antibodies present in the serum binding to peptides. The platform uses next-generation sequencing to determine which specific peptide sequences are bound by antibodies in the sample, with the pattern of antibody-peptide binding providing data that can be used to determine, for instance, pathogen antigens that are particularly antigenic or patterns of antibody production that can be used for diagnosis of a disease.
Serimmune is one of several firms using high-density peptide arrays to profile immune responses to disease, including Chandler, Arizona-based HealthTell and Armune BioScience, which Exact Sciences acquired in 2018. A potential advantage of looking at immune response markers as opposed to conventional protein or molecular markers is the fact that the immune cell replication involved in immune response provides a natural amplification of the signal, making it potentially possible to detect disease earlier or with more accuracy than can be done with traditional markers.
In the case of vaccine and serology research like Serimmune is pursuing in its COVID-19 work, being able to profile a patient's immune response with high resolution allows for identification of highly immunogenic viral proteins or peptides that could inform what components should be used in vaccines or antibody-based tests, Nasser said.
He noted that the firm's relationship with Merck is focused primarily on infectious disease as are several of its other pharma relationships.
Typically, Serimmune uses its platform to run clinical samples and look for antibody binding patterns that distinguish those samples from control groups and from that data identify the antigens triggering that immune response.
In its COVID-19 work the company reversed that procedure, taking the published proteome of SARS-CoV-2 and looking to see whether samples run prior to the emergence of the disease showed any immune response to the virus' peptides.
"What we saw was that there was no immune response that we could detect," Nasser said, "and that was suggestive of the fact that there would be no innate antibody-mediated response to this novel virus. And that meant that we needed to take this disease very seriously, and we believed that it would be highly infectious and very lethal."
Prior to the outbreak, Serimmune had been collaborating with Yale University epidemiologist Albert Ko on a serology test capable of distinguishing between patients infected with Zika virus and dengue fever. In recent months, Ko's lab has refocused much of its work on SARS-CoV-2, and Serimmune has been working with the lab to identify differences in immune response that could result in differences in disease severity as well as antibodies that are key to neutralizing the virus.
The company is also in discussions with several of its existing pharma customers about using its platform "to identify the most immunogenic and selective components of the virus for use in next-generation vaccine technology," Nasser said. "We're engaged with a number of partners on that front both in non-human primate trials and human trials."
Nasser added that the company believed its platform could be useful in the development of highly specific serology tests, as well. A number of companies have begun producing serology tests for the disease, but, he noted that given the relatively low prevalence of COVID-19 in the population, serology tests will produce large numbers of false positives unless they have extremely high accuracy.
"Based on the estimated prevalence of the virus in the US right now, [performance] really needs to be in the upper 99 percent [range]," he said, adding that the company has demonstrated with serology testing in other infectious diseases that this level of performance is within reach of its platform.
"So, we are hoping that we can identify antigens that will enhance the specificity of serology-based testing," Nasser said. He added that Serimmune would most likely not run these tests as it does not currently have a CLIA facility, but said that the company was interested in working with national labs about adapting tests based on its findings to a higher-throughput format.
"We have shown that we can take these immune motifs and put them on other diagnostic platforms quite effectively," he said, noting that the company has ported findings from previous infectious disease research to bead-based formats and lateral flow assays.
Nasser said that the company does plan to open a CLIA lab in the next nine months and that it expects it will offer a COVID-19 test out of that facility as its initial clinical product.