Oxford BioMedica announced that primary endpoints have been achieved at the interim stage of two Phase II trials in patients with Stage IV colorectal cancer receiving TroVax alongside chemotherapy
TroVax is the company's novel cancer immunotherapy product against the tumour associated antigen 5T4.
The primary endpoints are safety and demonstrable anti-tumour immune responses against the 5T4 tumour antigen.
The results from an interim analysis of both trials, initiated in 2003, showed that the combination of TroVax and standard of care chemotherapy is safe and that patients mount specific immune responses to the 5T4 antigen.
Full recruitment is imminent across both trials with 36 of 37 projected patients enrolled.
The objective is to have ten evaluable patients in each setting.
The interim results are based on 13 patients in total, who have reached an interim analysis point defined as four TroVax immunisations and more than eight cycles of chemotherapy.
There have been no serious adverse events associated with TroVax treatment and the product was well tolerated.
11 of the 13 patients (85%) mounted antibody and/or cellular immune responses to the 5T4 tumour antigen following four immunisations with TroVax.
The company expects to report full safety and immunological data in mid-2005 when all patients will have received 12 cycles of chemotherapy and 6 doses of TroVax.
At this time, tumour response rates will also be determined.
TroVax plus IFL chemotherapy.
The protocol of the first Phase II trial is six immunisations of TroVax alongside chemotherapy cycles of irinotecan, 5-fluorouracil (5FU) and leucovorin (a combination referred to as IFL).
A total of 19 patients have been enrolled.
Ten patients have reached the interim analysis point.
Nine out of ten patients (or 90%) have mounted specific anti-tumour immunological responses to the 5T4 antigen.
TroVax plus FOLFOX chemotherapy The second Phase II trial protocol is similarly six immunisations of TroVax alongside cycles of oxaliplatin, 5FU and leucovorin (referred to as Folfox).
The trial is fully recruited at 17 patients.
Three patients have reached the interim analysis point and two of these (or 67%) have shown anti-5T4 immune responses to date.
Commenting on the Phase II results, Alan Kingsman, chief executive of Oxford BioMedica, said, "We are very pleased with the progress of our first Phase II trials with TroVax.
"The high number of anti-5T4 responses at this interim stage suggests that patients are able to mount an anti-tumour immune response even in the context of chemotherapy treatment.
"In our earlier Phase I/II trials, it was clear that anti-5T4 immune responses correlated with improved patient survival.
"We now feel confident that TroVax has a role to play in the treatment of colorectal cancer."
