OncoSec Medical Inc, San Diego, a company developing DNA-based intratumoral cancer immunotherapies, recently announced a collaboration with PerkinElmer Inc and the University of California, Los Angeles (UCLA), to help researchers develop biomarker tests for evaluating a patient’s immune response to cancer.

According to OncoSec, the research supports an ongoing shift in oncology toward therapeutic strategies that stimulate the patient’s own immune defense system to combat cancer. The approach uses PerkinElmer’s new imaging-based staining methods to quantitatively evaluate CD8+ T-cell density in tumor biopsies.


Paul Tumeh, MD

OncoSec is a biopharmaceutical company developing its investigational ImmunoPulse intratumoral cancer immunotherapy, which is designed to enhance the local delivery and uptake of DNA IL-12 and other DNA-based immune-targeting agents. Clinical studies of ImmunoPulse have demonstrated an acceptable safety profile and preliminary evidence of anti-tumor activity in the treatment of various skin cancers, as well as the potential to initiate a systemic immune response without the systemic toxicities associated with other treatments.

UCLA investigators Paul Tumeh, MD, and Antoni Ribas, MD, and colleagues recently published results from this assay, demonstrating a strong correlation between the density of CD8+ T cells located at the invasive edge of melanoma lesions, and the probability of response to Merck’s pembrolizumab (Keytruda).1 Using quantitative image analysis, the researchers demonstrated that the number of CD8+ T cells/mm2 at the tumor margin was the feature most predictive of response and nonresponse to pembrolizumab.


Robert H. Pierce, MD

“Dr Tumeh has demonstrated the potential of applying his highly quantitative approach to assessing the ‘stalled’ CD8+ lymphocytes, which are the key effector cells driving response to anti-PD-1 therapy,” says Robert H. Pierce, MD, chief scientific officer at OncoSec Medical and a coauthor of the Nature study. “This work has the potential to identify responders from nonresponders.

“Dr Tumeh’s work, combined with PerkinElmer’s technology, may lead to the development of a critical diagnostic tool for identifying and classifying nonresponders to anti-PD-1 monotherapy,” Pierce adds. “These nonresponders may benefit from a combination approach of ImmunoPulse with checkpoint inhibitors, like anti-PD-1, where ImmunoPulse has the potential to convert nonresponders to responders.”

PerkinElmer has developed a new multiparametric immunohistochemistry analysis platform consisting of its Vectra automated quantitative pathology imaging system and its Opal multiplex tissue staining assays, which together can help scientists perform biomarker research to develop a potentially predictive assay for identifying the nonresponder population. OncoSec believes there is a significant unmet medical need to develop combination therapies for patients who do not respond to checkpoint inhibitors, such as anti-PD-1 (or anti-PD-L1) as a monotherapy.

“The analytical needs of both UCLA and OncoSec are well aligned with our unique technical capabilities,” says Brian Kim, president for life sciences and technology at PerkinElmer. “This project complements our focus on enabling research to reveal the intricacies of immuno-oncologic interactions. Through this work with UCLA and OncoSec, we think we can make a meaningful contribution toward assisting researchers in improving outcomes for patients.”

For more information, visit OncoSec Medical.


1. Tumeh PC, Harview CL, Yearley JH, et al. PD-1 blockade induces responses by inhibiting adaptive immune resistance. Nature. 2014;515(7528):568–571; doi: 10.1038/nature13954. Corrected online November 27, 2014.