SINGAPORE – A few months after releasing its phase 1 and 2 data, OSE Immunotherapeutics, which is based in Nantes, France, has announced positive results for its therapeutic vaccine to treat cancer. Following its promising findings concerning early-stage melanoma, pancreatic cancer, ENT cancers, and HPV-associated anogenital cancer,
The results suggest that Tedopi is the most developmentally advanced therapeutic vaccine for cancer.
The data from Atalante-1 were presented at the World Conference on Lung Cancer and were simultaneously published in Annals of Oncology.
Tedopi is composed of synthetic tumoral neo-epitopes (peptide fragments) that target five tumoral antigens, permitting the activation of tumor-specific T-lymphocytes for patients who are HLA-A2 positive. In 95% of cases, tumors express at least one of these five antigens. The aim of integrating these five antigens is to prevent immune escape. The technology uses the human leukocyte antigen (HLA) system, one of the keys for presenting antigens to T-lymphocytes. The vaccine is effective for patients who express the HLA-A2 gene, which is present in around half of the population. The HLA-A2 biomarker, detected via a blood test, can identify appropriate patients.
Study protocol
In the Atalante-1 trial, participants had locally advanced (unresectable and not eligible for radiotherapy) or metastatic (without alteration of the EGFR and ALK genes) non–small cell lung cancer that was resistant to previous immunotherapy. They had an HLA-A2 phenotype, as determined by a blood draw to determine whether their immune system could respond to the vaccine.
In this trial, 219 patients were randomly assigned in a 2:1 ratio to receive the vaccine or standard-of-care chemotherapy (80% received docetaxel). The vaccine was administered subcutaneously on day 1 every 3 weeks for six cycles. After that point, the vaccine was administered every 8 weeks until 1 year of treatment and every 12 weeks thereafter. The primary endpoint was overall survival.
Secondary resistance
The plan was to enroll 363 patients in the protocol, but the study did not complete its recruitment phase because of the COVID-19 pandemic. As a result, the study was stopped after the enrollment of 219 patients.
“It didn’t have the power we would have liked, but it helped us understand that the people who benefited the most from the vaccine were patients who had responded to immunotherapy in the past. These patients have what is called ‘secondary resistance,’ ” explained Benjamin Besse, MD, PhD, during a press conference organized by OSE Immunotherapeutics. Dr. Besse, the study’s principal investigator, is the director of clinical research at Gustave Roussy, Villejuif, France.
Overall, the results weren’t significant. But the results were positive for patients who had previously responded well to immunotherapy for at least 3 months. Of the 219 patients, 118 (54%) had a positive response.
Among these patients with secondary resistance to immunotherapy, median OS was 11.1 months with Tedopi versus 7.5 months with docetaxel.
For these patients, the risk of death was reduced by 41% with the vaccine, compared with chemotherapy. Overall, 44% of patients lived for another year after receiving Tedopi, versus 27.5% with docetaxel.
“This study is a positive signal for overall survival in the selected population. In this study of 219 patients, we realized that just half of patients really benefited from the vaccine: those who had previously responded to immunotherapy,” said Dr. Besse. “The study needs confirmation from a further, larger phase 3 study in more than 300 patients with secondary resistance to immunotherapy to give us the statistical power we need to convince the regulatory authorities.”