Chinese clinical-stage biotechnology company NGGT Inc (Next Generation Gene Therapeutics) announced on Monday positive new data on NGGT002, a clinical-stage gene therapy candidate intended for the treatment of Phenylketonuria (PKU).

An investigator-initiated trial (IIT) conducted in China demonstrated the safety and efficacy of NGGT002 for the treatment of PKU, a rare genetic disorder caused by a mutation in the phenylalanine hydroxylase (PAH) gene that causes an elevated blood level of phenylalanine and results in progressive intellectual and behavioural impairments, skin rashes, movement disorders and seizures. Five out of six patients receiving a high dose of NGGT002 in the study demonstrated a level of plasma phenylalanine within the normal range after three weeks of drug administration. The first patient dosed with NGGT002 in the IIT trial showed a persistent plasma phenylalanine level within the normal range 40 weeks after the drug was dosed.

Phase I/II clinical trials in the US and China have been initiated to evaluate the safety and efficacy of NGGT002 in adult patients with PKU. First patients in both trials will be dosed based on the effective dose which has been proved in the IIT study.

The US-based clinical trial, a Phase I/II, open-label, multiple-centre, dose escalation and cohort expansion study, is intended to assess the safety and efficacy of NGGT002, an rAAV-based vector carrying a functional copy of the human PAH gene, in adult patients with classic PKU. Patients in two dose cohorts are to receive a single administration of NGGT002 and will be followed for efficacy for one year and safety for five years.

Yiting Liu, PhD., NGGT VP of Translational Research, said: "We are pleased with the results from our investigator-initiated trial, as they show great promise for NGGT002 to serve as a safe and effective treatment for PKU. With our initial 40-week span of positive results, we are optimistic that our Phase I/II clinical trials will further elucidate NGGT002's potential to treat this rare and debilitating disease in a lasting manner."