T-VEC (Talimogene laherparepvec, Imlygic...whatever you want to call it) - oncolytic virotherapy may improve the efficacy of anti-PD-1 by changing the tumor microenvironment!!

Those of you who have hung around this site for more than ten minutes know I have long been yelling about the benefits of intralesional/intratumoral therapies, especially when combined with systemic thereapies.  This synopsis of the latest ASCO report covers much of the data:  ASCO 2017: All things intralesional/intratumoral

Now there's this:

Oncolytic Virotherapy Promotes Intratumoral T Cell Infiltration and Improves Anti-PD-1 Immunotherapy. Ribas, Dummer, Puzanov, ...Hodi, Long. Cell. 2017 Sep 7.  

Here we report a phase 1b clinical trial testing the impact of oncolytic virotherapy with talimogene laherparepvec on cytotoxic T cell infiltration and therapeutic efficacy of the anti-PD-1 antibody pembrolizumab. Twenty-one patients with advanced melanoma were treated with talimogene laherparepvec followed by combination therapy with pembrolizumab. Therapy was generally well tolerated, with fatigue, fevers, and chills as the most common adverse events. No dose-limiting toxicities occurred. Confirmed objective response rate was 62%, with a complete response rate of 33% per immune-related response criteria. Patients who responded to combination therapy had increased CD8⁺ T cells, elevated PD-L1 protein expression, as well as IFN-γ gene expression on several cell subsets in tumors after talimogene laherparepvec treatment. Response to combination therapy did not appear to be associated with baseline CD8⁺ T cell infiltration or baseline IFN-γ signature. These findings suggest that oncolytic virotherapy may improve the efficacy of anti-PD-1 therapy by changing the tumor microenvironment. 

The more we know....  Hang in there, ratties!!!  - c