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 company-funded phase 3 Atalante-1 trial has shown the benefits of the Tedopi (OSE2101) vaccine in treating patients with advanced non–small cell lung cancer who are on their second or third line of treatment. 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.
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 (OS).
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. Besse, the study's principal investigator, is the director of clinical research at Gustave Roussy in 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, vs 7.5 months with docetaxel.
For these patients, the risk of death was reduced by 41% with the vaccine in comparison with chemotherapy. Overall, 44% of patients lived for another year after receiving Tedopi, vs 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 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."
Fewer serious adverse effects were reported with the vaccine than with chemotherapy (11.4% with Tedopi and 35.1% with docetaxel).
The vaccine also allowed patients to maintain a better quality of life. Scores from the Quality of Life Questionnaire Core 30, which explores several areas of daily life, were better with the vaccine. Change in patients' overall well-being was delayed in the vaccine group: 3.3 months in the chemotherapy arm vs 9 months in the vaccine arm.
"The vaccine was well tolerated. It has benefits in terms of controlling disease symptoms and causes few side effects. Chemotherapy with docetaxel, meanwhile, is more toxic and may affect a patient's overall well-being. It causes hair loss in practically 100% of patients, induces neuropathy, makes hands and feet swell, damages the nails, is associated with nausea and vomiting...." noted Besse. He went on to say that after the trial, of the patients who stopped receiving the vaccine or chemotherapy (either for toxicity reasons or for disease progression), those who had been given the vaccine responded better to the subsequent chemotherapy "because their overall health was better."
The clinical development of Tedopi is ongoing. Three trials are currently taking place. One study is comparing the Tedopi vaccine plus docetaxel with Tedopi plus nivolumab (immunotherapy not used as a first-line treatment) to determine whether the effects of these treatment combinations might might be enhanced for patients with previously treated lung cancer.
Another study relating to ovarian cancer is in the recruitment phase. The researchers seek to evaluate the vaccine alone or in combination with pembrolizumab for patients with platinum-sensitive ovarian cancer. Results from both trials are expected in 2025.
The third trial seeks to assess FOLFIRI as maintenance therapy or FOLFIRI as maintenance plus Tedopi for patients with pancreatic cancer to improve disease management. Efficacy data are expected next year.
OSE Immunotherapeutics is simultaneously working on a companion biomarker, the HLA-A2 test.
The study was funded by OSE Immunotherapeutics. Besse disclosed the following conflicts of interest (research funding, institution): AbbVie, Amgen, AstraZeneca, Chugai Pharmaceutical, Daiichi-Sankyo, Ellipse Pharma, EISAI, Genmab, Genzyme Corporation, Hedera Dx, Inivata, IPSEN, Janssen, MSD, Pharmamar, Roche-Genentech, Sanofi, Socar Research, Taiho Oncology, and Turning Point Therapeutics.
This article was translated from the Medscape French Edition.
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Cite this: Therapeutic Vaccine Shows Promise in Treating Lung Cancer - Medscape - Sep 19, 2023.