Efficacy of Talimogene Laherparepvec (T-VEC) Therapy in Patients with In-Transit Melanoma Metastasis Decreases with Increasing Lesion Size
Talimogene laherparepvec (T-VEC) is the first injectable oncolytic viral therapy approved for in-transit melanoma metastasis, with a reported overall response rate (ORR) of 25% and complete response rate (CRR) of 10%. To ascertain the role of patient selection on outcomes in routine practice, we evaluated the impact of patient, lesion, and treatment factors on clinical response.
Medical records were extracted for patients with recurrent stage IIIB–IV melanoma completing T-VEC at Duke University Medical Center between 1 January 2016 and 1 September 2018. Kaplan–Meier analysis assessed time to response and survival, while logistic regression measured associations of clinicopathologic status, lesion burden, T-VEC dosing, and use of prior and concurrent therapy with ORR and CRR.
Of 27 patients, an objective response was observed in 11 (40.7%), including one patient with partial response (3.7%) and 10 with complete response (37.0%). Time to complete response and overall response was a median 22 weeks (95% confidence interval [CI] 2.0–41.9 weeks and 15.8–28.2 weeks, respectively), and median progression-free survival was 17 weeks (95% CI 0–36 weeks). Logistic regression demonstrated each millimeter increase in maximum lesion diameter predicted decreased ORR (odds ratio [OR] 0.866, 95% CI 0.753–0.995; p = 0.04). Stage IV disease (OR 0.04, 95% CI 0.00–0.74; p = 0.031) and programmed death-1 inhibitor treatment (OR 0.06, 95% CI 0.01–0.74; p = 0.028) also predicted reduced clinical response.
This study corroborates recent data suggesting response rates to T-VEC may be higher than reported in clinical trials, arising in part from patient selection. T-VEC lesion diameter was persistently associated with clinical response and is a readily assessed predictor of successful T-VEC therapy.
GB, PM, and JS were responsible for treating patients and recording clinical experiences in electronic medical records. SM and JH conducted a review of medical records, conducted data analysis, and prepared this manuscript.
JS served on the T-VEC Speaker’s Bureau, Amgen Inc., 2015–2018. SM and JH received travel funding from the Polka Dot Mama Melanoma Research Foundation to attend the 2019 Society of Surgical Oncology (SSO) National Conference and the SSO Regional Therapy Conference, respectively. There are no other relevant conflicts of interest to disclose in relation to the subject matter of this manuscript.
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