Mallinckrodt has started patient recruitment in a Phase IIa clinical trial of MNK-6106 (L-ornithine phenylacetate) for the treatment of hepatic (liver) cirrhosis and hepatic encephalopathy (HE).

Said to be an ammonia scavenger, MNK-6106 was acquired by Mallinckrodt in December 2017 when the company purchased Ocera Therapeutics.

The investigational candidate is being developed for post-discharge continuity of care and is intended to help minimise the risk of recurrent HE episodes.

During the randomised, open-label Phase IIa study, MNK-6106 will be compared to rifaximin for its pharmacokinetics, pharmacodynamics, and safety.

The trial will enrol around 48 adult men and non-pregnant women with hepatic cirrhosis and a history of at least two or more documented HE episodes.

The primary objective is the drug candidate’s pharmacological effect after oral administrations with rifaximin as a control. The trial will also track the absolute and percentage change in plasma ammonia from baseline to five days.

Mallinckrodt expects to complete the Phase IIa trial by the first quarter next year.

Mallinckrodt executive vice-president and chief scientific officer Steven Romano said: “The evaluation of the oral formulation will allow us to gain insights into the potential utility of this compound to manage patients whose acute episode of HE has resolved, and who may require longer-term treatment to reduce the likelihood of future episodes and potential complications.”

By the end of this year, the company intends to initiate enrolment in a Phase III study of MNK-6105 (L-ornithine phenylacetate) in acute HE patients being treated at the hospital.

Mallinckrodt also acquired MNK-6105 with Ocera Therapeutics.