HBsAg and HDV RNA reduction with REP 2139-Ca and peg-INF alpha 2a in chronic HBV/HDV infection.
Nucleic acid polymers (NAPs) inhibit the release of HBsAg and the NAP REP 2139 can efficiently clear HBsAg from the blood of patients with HBV mono-infection. REP 2139-Ca therapy combined with pegylated interferon alpha-2a is being evaluated in Caucasian patients with HBV/HDV co-infection (NCT02233075).
Patients received REP 2139-Ca once weekly for 15 weeks (500 mg) by 2 h IV infusion, followed by combined therapy for 15 weeks with pegylated interferon alpha-2a (180ug SC qW) with 250 mg REP 2139-Ca. Patients then transition to 33 weeks of pegylated interferon alpha-2a monotherapy. HDV RNA, HBV DNA, HBsAg and anti-HBs are followed every two weeks using standard assays (Robogene RT- PCR, Abbott RealTime HBV, Abbott Architect).
On treatment, observed HBsAg reductions are currently *5 logs in 6 patients (all \1 IU / ml), *3 logs in three patients and *0.5 to 1.5 logs in three patients. HDV RNA is currently undetectable in ten patients (*5 to 8 log reduction from baseline) with *3 and *5 log reductions observed in the other two patients. Substantial elevation (389–15,408 mIU/ml) of serum anti-HBs and the development of liver flares were only observed with the onset of exposure to pegy- lated interferon alpha-2a and was only evident in patients with serum HBsAg \1 IU / ml at the start of immunotherapy.
REP 2139-Ca is able to achieve rapid reductions in serum HBsAg and HDV RNA in Caucasian patients with HBV/HDV infection. REP 2139-Ca may become an important new therapeutic option for patients with chronic HBV/HDV infection.