All patients vaccinated with CDX-110 in the Phase IIa ACT II extension study showed a tumor-specific immune response, a significant improvement over previous vaccines and over CDX-110 alone. Patients vaccinated in conjunction with the daily temozolomide (TMZ) dose had a statistically significant increase in anti-EGFRvIII antibody titers (P=0.028) compared to patients that received the standard 200mg/m2 dose of TMZ.
In addition, the delayed type hypersensitivity response (DTH) following vaccination was also greater in the patients receiving the continuous 21 day TMZ dose (P=0.05). Early time to progression and overall survival data also look very promising. These data suggest that chemotherapy enhances the induction of a vaccine specific immune response, and that daily chemotherapy may further enhance the vaccine’s effect.
Tom Davis, Avant’s chief medical officer, said: “We expect to present survival data from this study at ASCO in June, 2008. We also eagerly await the data from Avant’s currently enrolling randomized Phase IIb/III study, ACT III, which is designed to confirm the Phase IIa results.”