| Abstract: | ![]()
MUC1 is expressed by glandular epithelial cells. It isoverexpressed in the majority of breast tumours, making it apotential target for immune therapy. The objectives of thepresent study were to evaluate the anti-tumour activity andtolerance of repeated administration of TG1031 (an attenuatedrecombinant vaccinia virus containing sequences coding for humanMUC1 and the immune stimulatory cytokine IL-2) in patients withMUC1-positive metastatic breast cancer. This was an open-label,randomised study comparing two dose levels, 5 × 10E6and 5 × 10E7 pfu, with 14 patients in each arm.The treatment was administered intramuscularly every 3 weeks forthe first 4 doses and every 6 weeks thereafter, untilprogression. Two patients had a partial tumour regression(> 50%), and 15 patients had stable disease as their bestoverall response until at least the 5th injection. Partialregression lasted for 11 months in one patient and for 12 monthsin the second patient who then underwent surgical resection ofher hepatic metastases. The most frequent adverse events includedinflammation at injection site: 7 patients, itching or pain atinjection site: 5 patients, and moderate fever: 6 patients. Oneresponding patient developed antinuclear, anti-DNA, and increasedanti-TPO antibodies after the fifth injection, and which resolvedat the end of treatment. The treatment regimes were welltolerated with a low toxicity profile. Although clinical efficacyremains limited, this study demonstrates the potential use ofMUC1-based immune therapy in breast cancer. |
