Vaccitech plc, a clinical-stage biopharmaceutical company engaged in the discovery and development of novel immunotherapeutic and vaccines, announced a promising interim analysis of safety and efficacy data from the HBV002 study, including a review of surface antigen (HBsAg) levels in CHB patients.
Data from an interim analysis of immunogenicity and safety in Groups 1 and 2 were recently reported at the 2021 AASLD The Liver Meeting®, and a broader efficacy data set has now been analyzed, including patients receiving VTP-300 in combination with low-dose nivolumab (Groups 3 and 4).
The company has concluded that the results support a protocol change that will lead to a focus on enrolling patients into Groups 2 and 3.
The analysis of Group 3, patients on antivirals for at least 12 months with undetectable HBV DNA and a mean starting HBsAg level of 441 IU/ml, showed:
Mean of greater than one log decrease (-1.04) and a greater than one log decrease in HBsAg in 3/6 patients at 3 months.
HBsAg in one patient was undetectable 3 months after starting the immunotherapy regimen.
One patient with a decrease experienced a transaminase flare after the MVA boost plus nivolumab that resolved over 3 weeks.
Despite the very small patient numbers the difference in mean HBsAg between Group 3 and the other groups was highly significant (p < 0.01).
In addition, in the VTP-300 group without nivolumab (Group 2), one patient had a 1.29 log and one patient had a 0.70 log decrease at month 3 (2/6).
Enrollment into HBV002 will continue into 2022 and a further interim analysis, including more HBsAg level data, is anticipated during the first half of 2022.
“These interim efficacy results of the ongoing HBV002 study are very promising and build upon recent safety and T cell immunogenicity data from Groups 1 and 2 that were presented at AASLD this year,” said Thomas Evans,, Chief Scientific Officer of Vaccitech. “The new analysis showed that some patients on chronic antivirals receiving VTP-300 alone, as well as in combination with a low-dose checkpoint inhibitor, experienced meaningful decreases in HBsAg levels.”