ABSTRACT
The additional author support information was erroneously omitted from the Supplementary Information. This has been corrected online.
ABSTRACT
Patients with glioblastoma currently do not sufficiently benefit from recent breakthroughs in cancer treatment that use checkpoint inhibitors1,2. For treatments using checkpoint inhibitors to be successful, a high mutational load and responses to neoepitopes are thought to be essential3. There is limited intratumoural infiltration of immune cells4 in glioblastoma and these tumours contain only 30-50 non-synonymous mutations5. Exploitation of the full repertoire of tumour antigens-that is, both unmutated antigens and neoepitopes-may offer more effective immunotherapies, especially for tumours with a low mutational load. Here, in the phase I trial GAPVAC-101 of the Glioma Actively Personalized Vaccine Consortium (GAPVAC), we integrated highly individualized vaccinations with both types of tumour antigens into standard care to optimally exploit the limited target space for patients with newly diagnosed glioblastoma. Fifteen patients with glioblastomas positive for human leukocyte antigen (HLA)-A*02:01 or HLA-A*24:02 were treated with a vaccine (APVAC1) derived from a premanufactured library of unmutated antigens followed by treatment with APVAC2, which preferentially targeted neoepitopes. Personalization was based on mutations and analyses of the transcriptomes and immunopeptidomes of the individual tumours. The GAPVAC approach was feasible and vaccines that had poly-ICLC (polyriboinosinic-polyribocytidylic acid-poly-L-lysine carboxymethylcellulose) and granulocyte-macrophage colony-stimulating factor as adjuvants displayed favourable safety and strong immunogenicity. Unmutated APVAC1 antigens elicited sustained responses of central memory CD8+ T cells. APVAC2 induced predominantly CD4+ T cell responses of T helper 1 type against predicted neoepitopes.
Subject(s)
Cancer Vaccines/immunology , Cancer Vaccines/therapeutic use , Glioblastoma/diagnosis , Glioblastoma/therapy , Precision Medicine/methods , Adult , Aged , Antigens, Neoplasm/immunology , CD8-Positive T-Lymphocytes/immunology , Epitopes, T-Lymphocyte/immunology , Female , Glioblastoma/immunology , HLA-A Antigens/immunology , Humans , Immunologic Memory/immunology , Male , Middle Aged , T-Lymphocytes, Helper-Inducer/immunology , Treatment OutcomeABSTRACT
Hydroxyaminolactams have been used as constrained surrogates of the Ser-Leu dipeptide in the synthesis of analogues of the cycloheptapeptide stylostatin 1 (2). The rate of cyclization through formation of the Ile-Pro amide bond allowed us to prove that the valerolactams used induced a turn in the linear precursor. Ring closure at the Pro-Phe amide bond was much quicker and provided access to larger amounts of the target structures, with high purity. The conformation of psi-stylostatin 4 was compared to that of native stylostatin 1 using NMR analysis. The ability of three psi-stylostatins and the native stylostatin 1 to inhibit growth of cancer cell lines was tested. None of the compounds showed activity below 1 microM. A possible relationship between the decrease in activity and the presence of the piperidone Ser-Leu surrogate is considered.
