Vaccine therapy INVAC-1 (a DNA vaccine encoding human telomerase reverse transcriptase (hTERT)), is a new class of anti-cancer agents and was evaluated in a Phase 1 trial (INVAC1-CT-101 study) in patients with advanced cancer. We propose to study tumour patterns of response on imaging evaluations of patients under vaccine in a retrospective CT study.
The tumour growth rate (TGR) of the tumor burden (sum of lesions) was calculated before and during therapy. Patients with decrease of the TGR after initiation of therapy were considered responders whereas patients with stability or increase of the TGR were considered non responders. Overall survival (OS) and response according to anatomical location were also analysed.
10/19 patients were responders according to the tumour growth rate. The median [IQR] of OS was 9.6 month [6.8, 13.3] versus 5.3 month [5.1, 15.0] for non-responders (p = 1.3.10-5). Regarding organ sensitivity to vaccine therapy, we observed that none of the liver metastases responded to treatment, whereas the majority of lymph node lesions responded.
The decrease of the tumor growth rate in patients treated by vaccine therapy INVAC-1 could predict a benefit in terms of overall survival. The efficiency could vary depending on the location of the metastases.
Clinical trial identification
Legal entity responsible for the study
R. Defrance, T. Huet, L.D. Pierre, V. Doppler: Salaried: Invectis. L. Fournier: Funded: Invectys; Speaker fees: Novartis, Merck, Pfizer. All other authors have declared no conflicts of interest.