A long-term follow up on an earlier published clinical trial of 15 stage III-IV NSCLC patients treated with and IDO peptide vaccine.1
15 patients with stage III-IV NSCLC in disease stabilization after standard chemotherapy were treated with subcutaneous vaccinations (100 µg IDO5 peptide, seq ALLEIASCL, in 900 µl Montanide). Patients were enrolled from 2010 to 2012 and treated biweekly for 2.5 months and thereafter monthly until progression or up to 5 years. As published in Clin Cancer Res 2013, the vaccine was well tolerated and a long-lasting PR + SD (>8.5 months) was seen in 47% of the patients. A long-term follow-up has been made, investigating the long term clinical benefit and immunity.
3 of the 15 patients are still alive (May 2017) corresponding to a 5-year overall survival of 20%. One was excluded due to progression after 11 months; the other two have continued vaccination for 5 years and have both received 56 vaccines in total. One of the two patients developed a partial response of target lesions in the liver 15 months after the first vaccine and has been in stable disease ever since. The other patient had a solitary metastasis in a retroperitoneal gland at baseline and at the 1st evaluation scan the patient had no sign of malignancy and has been tumour free ever since. The vaccine was well tolerated for all 5 years. Analyses of PBMCs every 3rd to 6th month during treatment of the two long-term responders demonstrated a stable CD8+ T-cell population. The percentage of NK cells, MDSCs and Tregs were stable over time, demonstrating no sign of toxicity of the immune cells in the blood. Presence of IDO-specific CD8+ T cells were demonstrated by IFN-γ Elispot and could be detected in both patients at several time points during vaccinations.
The vaccine was well tolerated with no severe toxicity for administration up to five years. Two of 15 patients are long-term survivors with ongoing clinical response five years after 1. vaccination. 1. Iversen, T. Z. et al. Long-lasting disease stabilization in the absence of toxicity in metastatic lung cancer patients vaccinated with an epitope derived from indoleamine 2,3 dioxygenase. Clin. Cancer Res. 20, 221–232 (2014).
Clinical trial identification
Legal entity responsible for the study
Herlev and Gentofte Hospital, Center for Cancer Immune Therapy, Department of Hematology and Oncology, Denmark
IO Biotech, Denmark
All authors have declared no conflicts of interest.