German biotech firm ORYX has completed a Phase I/IIa trial of the therapeutic vaccine, MicOryx, to treat patients with advanced microsatellite instable (MSI-H-) colorectal cancer.
The open label, single centre trial included 22 patients (UICC stage III or IV), who had received standard chemotherapy.
The trial’s Phase I part evaluated safety and toxicity as the primary endpoint in six patients, while Phase IIa assessed the induction of cellular and humoral immune responses against MicOryx in 16 patients evaluated by CT or MRI scans according to RECIST.
According to the company, the vaccine was safe and induced humoral and cellular immune responses.
Many cancers occur from the lack of DNA mismatch repair (MMR) resulting in the accumulation of thousands of single deletions or insertions at coding microsatellites and these mutations lead to the inactivation of specific proteins and the expression of frameshift peptides (FSPs).
ORYX CEO and founder Dr Bernard Huber said: "This is the first of a series of three clinical trials ongoing at ORYX to report successful completion this year.
"The data of the MicOryx trial confirms the great potential of our therapeutic MSI vaccine.
"Together with the scientists and inventors of this treatment strategy at the University of Heidelberg, we strongly believe that therapeutic strategies directed against FSP antigens may hold strong potential for the treatment and cure of MSI-H colorectal cancers."
The company said that in patients with MSI-H colorectal cancer, humoral and cellular immune responses against FSPs occur spontaneously, while in healthy people such immune responses are not observed.
Clinical development portfolio of the company consists of an oncolytic virus and two therapeutic cancer vaccines.
Image: Micrograph of an invasive cecal adenocarcinoma, a type of colorectal cancer. Photo: courtesy of Nephron