|The following article features coverage from the American Society of Clinical Oncology 2020 meeting. Click here to read more of Cancer Therapy Advisor‘s conference coverage.|
Results from a phase 1 study showed that intrahepatic injection of T-VEC, a genetically modified oncolytic herpes simplex virus (HSV)-1, in combination with pembrolizumab was feasible and tolerable in patients with hepatocellular carcinoma (HCC) or liver metastases.
The data were presented by Joel Randolph Hecht, MD, from the David Geffen School of Medicine at the University of California, Los Angeles, as part of the ASCO20 Virtual Scientific Program.
“T-VEC is a genetically modified oncolytic HSV designed to selectively replicate within tumors and produce GM-CSF to enhance systemic tumor immunity,” Dr Hecht explained.
Previously T-VEC as a monotherapy has been established as safe and effective in melanoma.
The study was designed to assess the maximum tolerated concentration of T-VEC injection into liver tumors based on dose-limiting toxicities. The study included 3 cohorts of patients: A5 given 107 plaque-forming unit (PFU) per mL T-VEC plus pembrolizumab (7 patients), A6 given 108 PFU per mL T-VEC plus pembrolizumab (17 patients), and B5 given 107 PFU per mL T-VEC plus pembrolizumab (5 patients).
The median number of injections received was 4. The median duration of treatment was 88 days. There was 1 dose-limiting toxicity of cholestatic hepatitis in 6 evaluable patients in cohort A5. The patient was heavily pretreated with a high tumor burden, Dr Hecht noted. There were no dose-limiting toxicities in the other 2 cohorts.
The maximum tolerated concentration was 108 PFU per mL in non-HCC patients. Analysis of maximum tolerated concentration in patients with HCC is ongoing.
Common treatment-emergent/treatment-related adverse events included pyrexia (79.3%), chills (37.9%), and nausea (37.9%). Eight patients had grade 3 or worse treatment-emergent adverse events. No fatal adverse events were observed.
According to Dr Hecht, as of April 1, 2020, 1 patient with HCC in cohort B5 had a confirmed partial response that progressed after 4.3 months. One patient with microsatellite-stable colorectal cancer in cohort A6 had a confirmed partial response that has continued for 8.3 months. There are 8 patients with stable disease, and 6 of these have had stable disease lasting more than 6 months.
Read more of Cancer Therapy Advisor‘s coverage of the ASCO 2021 meeting by visiting the conference page.
Hecht JR, Pless M, Cubillo A, et al. Early safety from a phase I, multicenter, open-label clinical trial of talimogene laherparepvec (T-VEC) injected (inj) into liver tumors in combination with pembrolizumab (pem). Presented at: ASCO20 Virtual Scientific Program. J Clin Oncol. 2020;38(suppl):abstr 3015.