ISA Pharmaceuticals Presents Novel Data at the European Cancer Congress 2013: Strong Synergies Between Cancer Vaccine ISA101 and Chemotherapy

ISA Pharmaceuticals B.V., a clinical-stage biopharmaceutical company focusing on rationally designed therapeutic vaccines against cancer and persistent viral infections, today announced that it had presented novel data on its lead compound ISA101 at this year´s European Cancer Congress (ECCO-ESMO-ESTRO) in Amsterdam, The Netherlands.

In a preclinical mouse model of cancer, chemotherapy with cisplatin increased the therapeutic response to subsequent vaccination with an HPV16 synthetic long peptide (SLP®). While cisplatin or HPV-SLP® treatment alone increased survival, long-term survival was only achieved by combining chemotherapy with the vaccine.

These findings are further supported by a Phase I toxicity / immunogenicity study in 18 women with advanced or recurrent cervical cancer eligible for chemotherapy. Concurrent with standard chemotherapy (including carboplatin and paclitaxel), 12 patients received ISA101, a therapeutic cancer vaccine consisting of 13 synthetic long peptides from the E6 and E7 oncoproteins of HPV16. The control group (n=6) did not receive vaccination. The study demonstrates that chemotherapy does not cause lymphodepletion or suppression of cellular immune responses in patients. Patients showed shifts in leukocyte composition associated with increased dendritic cell function and improved memory T cell responses to common recall antigens. Patients treated with chemotherapy and ISA101 exhibited robust and sustained HPV16-specific proliferative T cell responses.

“We are pleasantly surprised that standard chemotherapy for late-stage cervical cancer is not immunosuppressive for T cells, and that it permits robust proliferative T cell responses to ISA101,” said Cornelis Melief, Chief Scientific Officer of ISA Pharmaceuticals. “Contrary to long-held beliefs, these results demonstrate that chemotherapy combines well with therapeutic cancer vaccines.”