JITC Letter from the Editor - September 2019

Dear JITC Readers,

There are several recent articles I would like to highlight in this September issue of the JITC digest, pointing to the progress we’ve been making toward understanding the immune system and cancer.

First, “PD-1 silencing impairs the anti-tumor function of chimeric antigen receptor modified T cells by inhibiting proliferation activity” by Jianshu Wang et al demonstrates yet another function of PD-1 in T cells. In this case, knock-down of PD-1 does not lead to increased anti-tumor activity; rather, silencing of PD-1 in CAR T cells inhibits their proliferation capability and differentiation, and impairs their anti-tumor effects.

“Development of a new fusion-enhanced oncolytic immunotherapy platform based on herpes simplex virus type 1” by Suzanne Thomas et al outlines the potential of a novel HSV-1-based oncolytic platform, whereby the engineered virus is armed with various modifications to increase its therapeutic effects, essentially allowing effective combination therapy through a single administered agent.

In the article, “Concurrent therapy with immune checkpoint inhibitors and TNF-alpha blockade in patients with gastrointestinal immune-related adverse events”, Yousef R. Badran and co-authors provide insight into management of one of the most common immune-related adverse events, enterocolitis. They describe five patients treated concurrently with checkpoint inhibitors and infliximab, all of whom had symptom resolution and disease control, providing physicians an example for management or severe cases of this common side effect. While the efficacy of this combination to control immune related enterocolitis awaits formal confirmation in controlled clinical trials, the results are indeed in line with recent observations in pre-clinical studies (Perez-Ruiz et al. Prophylactic TNF blockade uncouples efficacy and toxicity in dual CTLA-4 and PD-1 immunotherapy, Nature 2019).

Daruka Mahadevan et al describe a novel immune checkpoint inhibitor in “Phase I study of samalizumab in chronic lymphocytic leukemia and multiple myeloma: blockade of the immune checkpoint CD200”. In this first-in-human study, the authors observed encouraging efficacy through blockade of CD200 in hematologic malignancies, recommending further dosing optimization for future investigations.

Finally, “Characterization of a whole blood assay for quantifying myeloid-derived suppressor cells” by Minjun C. Apodaca et al addresses a pressing issue with a promising biomarker: quantification of circulating myeloid-derived suppressor cells. They identify a common pathway to their quantification using flow cytometry, and also point out a few pre-analytical variables that have significant impact on MDSC levels as well.

With best regards,

Pedro J. Romero, MD
Editor-in-Chief, Journal for ImmunoTherapy of Cancer

To view the entire September 2019 JITC Digest, please click here.