Clinical Cancer Research
February 1, 2020
Shailender B, Longino NV, Miller NJ, Kulikauskas R, Iyer JG, Ibrani D, Blom A, Byrd DR, Parvathaneni U, Twitty CG, Campbell JS, Le MH, Gargosky S, Pierce RH, Heller R, Daud AI, and Nghiem PDownload PDF
Purpose: IL12 promotes adaptive type I immunity and has demonstrated antitumor efficacy, but systemic administration leads to severe adverse events (AE), including death. This pilot trial investigated safety, efficacy, and immunologic activity of intratumoral delivery of IL12 plasmid DNA (tavo) via in vivo electroporation (i.t.-tavo-EP) in patients with Merkel cell carcinoma (MCC), an aggressive virus-associated skin cancer.
Patients and methods: Fifteen patients with MCC with superficial injectable tumor(s) received i.t.-tavo-EP on days 1, 5, and 8 of each cycle. Patients with locoregional MCC (cohort A, N = 3) received one cycle before definitive surgery in week 4. Patients with metastatic MCC (cohort B, N = 12) received up to four cycles total, administered at least 6 weeks apart. Serial tumor and blood samples were collected.
Results: All patients successfully completed at least one cycle with transient, mild (grades 1 and 2) AEs and without significant systemic toxicity. Sustained (day 22) intratumoral expression of IL12 protein was observed along with local inflammation and increased tumor-specific CD8+ T-cell infiltration, which led to systemic immunologic and clinical responses. The overall response rate was 25% (3/12) in cohort B, with 2 patients experiencing durable clinical benefit (16 and 55+ months, respectively). Two cohort A patients (1 with pathologic complete remission) were recurrence-free at 44+ and 75+ months, respectively.
Conclusions: I.t.-tavo-EP was safe and feasible without systemic toxicity. Sustained local expression of IL12 protein and local inflammation led to systemic immune responses and clinically meaningful benefit in some patients. Gene electrotransfer, specifically i.t.-tavo-EP, warrants further investigation for immunotherapy of cancer.
The authoritative source on Merkel cell carcinoma.
September 22, 2020
- What is a Merkel cell?
- What is Merkel cell carcinoma?
- Symptoms & appearance of Merkel cell carcinoma
- Causes of Merkel cell carcinoma
- Surgical excision
- Mohs micrographic surgery
- Radiation therapy
- Complementary & alternative therapies
- Clinical trials
- Adjuvant Avelumab in Merkel Cell Carcinoma Trial