Arrowhead Pharmaceuticals has added a triple-combination arm to its chronic hepatitis B virus (HBV) clinical trial. The cohort will assess ARO-HBV in combination with two undisclosed drugs selected by Johnson & Johnson. J&J secured the global rights to phase 1/2 RNAi therapy ARO-HBV last year for $175 million up front. The original deal committed J&J to paying a further $50 million when ARO-HBV entered phase 2, but the partners subsequently tweaked this part of the agreement to reward Arrowhead for kicking off an early-phase assessment of a triple combination to glean a preliminary look at its effects.