TG4040 alone reduced
HCV RNA by > 0.5 log IU/mL in 43% of patients during the TG4040 lead-in
(range 0.5-5.1 log decline).
In an intent-to-treat
analysis, complete early virological response rates (EVR) were 44% in the SOC
lead-in arm and 62% in the TG4040 lead-in arm, compared with 29% in the control
arm, a statistically significant difference.
In an analysis of
evaluable patients, corresponding cEVR rates were 46%, 64%, and 30%,
respectively.
In a week 24
intent-to-treat analysis, 67%, 76%, and 65%, respectively, maintained undetectable
viral load.
End-to-treatment
response (ETR) rates were 56% in the SOC lead-in arm and 62% in the TG4040
lead-in arm; evaluation of the TG4040 lead-in group was ongoing, but all 19
patients evaluated so far were undetectable.
Discontinuation rates
were relatively high, 40% in the SOC lead-in arm, 34% in the TG4040 lead-in
arm, and 35% in the control arm, with the most common reason being virological
failure (futility) at week 12 or 24.
Most patients
experienced some adverse events, but these were typical of those seen with
interferon. In total, 33% in the SOC lead-in arm and 59% in the TG4040 lead-in arm had
adverse events attributed to the vaccine, mainly injection-site swelling or
itching.
Seven people (11%) in
the SOC lead-in arm, 6 (10%) in the TG4040 lead-in arm, and 2 (6%) in the
control arm stopped due to adverse events.Three vaccine recipients developed
severe thrombocytopenia and 1 developed aplastic anaemia.
"[The]
primary objective of the study, improvement of cEVR, [was] reached in TG4040
lead-in arm," the investigators summarised. "TG4040 pre-vaccination
impacts significantly the slope of viral load decrease after [pegylated
interferon/ribavirin] initiation."
TG404
demonstrated a "good safety profile," but blood toxicity events are
being further studied.
"TG404 as
an active immunotherapy should be evaluated in combination with interferon-free
direct-acting antiviral treatment regimens," they recommended.
"These
data are important for TG4040 as they confirm the efficacy profile of our
therapeutic vaccine," Transgene CEO Philippe Archinardin said a company
press release. "As far as we know, they are unheard of for an
immunotherapy in HCV."