derived material before the vaccine peptides are defined," co-author Elaine Mardis Ph.D., told BioscienceTechnology.
Mardis is co-director of the Genome Institute of Washington University.
"We used conventional in vitro lab assays, called 'Elispot,' with an isolate from each patient, to refine the list of peptides we generated from the work above (genomics, comparison of binding affinity)," Mardis
"Our approach does consider heterogeneity by evaluating, using genomics, the common neoantigens present in several metastatic lesions," Mardis
"Therefore, we develop the most broadly tumor-reactive set of T-cells.
What we hope is that, like many other types of immunotherapy, we can establish that patients will have lasting or 'durable' responses, and they may indeed need only a single course of treatment."
The durability of the response is not optimal right now.
"The peak response occurred eight weeks after the last vaccine round, and one of the open questions about this approach is whether patients will continue to have a durable response," Mardis
"It's simply too early to know [although] we do think we can potentially culture the activated T cells so that patients can have a "booster shot" if needed."
can "absolutely" imagine bolstering the vaccine with complimentary therapies.
"We do anticipate a second trial that combines the precision vaccine with a checkpoint blockade therapy to evaluate whether this is a better 'tweak'," she
In response, Mardis
noted that, "in Figure 1A of the manuscript, we demonstrate that by sampling from several different tumor isolates for two of the patients, we were able to identify shared tumor-unique neoantigens.
said, the digital nature of massively parallel sequencing data "enables us to also select the neoantigen candidates that are present in the founder clone of the tumor.
But the bottom line, said Mardis
, is that "Dr.