The FDA asked Homology Medicines to modify the pheNIX gene therapy trial’s risk mitigation measures to prevent any serious issues that may arise.
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The U.S. Food and Drug Administration issued a clinical hold order on Homology Medicines’ pheNIX gene therapy trial due to elevated liver function tests.
The regulator asked the company to modify the study’s risk mitigation measures to prevent any serious issues that may arise. The pheNIX gene therapy trial is evaluating the effectiveness of the investigational treatment HMI-102 in adults with phenylketonuria (PKU).
PKU is an inherited condition caused by defects in the PAH gene, which creates the enzyme responsible for breaking down phenylalanine (Phe), a type of amino acid. It affects around 16,500 people in the U.S., and an estimated 300 newborns are diagnosed with the condition every year. If PKU is left untreated, Phe levels can accumulate to harmful levels and cause serious health problems.
The pheNIX study is designed for participants aged 18 to 55 who are diagnosed with classical PKU due to phenylalanine hydroxylase (PAH) deficiency and can take oral steroids for a certain period. It is not open to those who’ve had histories of HIV, hepatitis B or C, and alcoholism or drug abuse. PAH patients with underlying liver disease and those who are pregnant or intend to be pregnant during the study period will also not be allowed to participate.
Participants will receive a single intravenous administration of the PAH gene therapy HMI-102 and be observed for 52 weeks. After that, patients will be monitored for another four years to ensure stability.
Details of the latest FDA directive are unclear as of this writing, but Homology said it expects to receive a formal letter in the next 30 days. The company noted that it will work closely with the regulator to answer all questions and address any adjustments as needed. It also clarified that the clinical hold does not affect any of its other research and development activities in the pipeline, including the pheEDIT gene editing study of HMI-103 for PKU and the juMPStart trial of HMI-203 for Hunter syndrome.
“This hold on our PKU gene therapy trial is based on clinical observations in the pheNIX study and does not relate to CMC/manufacturing capabilities or Homology’s other clinical programs. We plan to provide next steps once we have more information following our FDA interactions,” said Homology President and CEO Arthur Tzianabos, Ph.D. in a statement.
The news comes just a few weeks after Homology announced it had signed a deal with the U.K.'s Oxford BioMedica to create a new AAV manufacturing and innovation business. The new entity, Oxford Biomedica Solutions, will leverage Homology’s manufacturing capabilities at its East Cost facility and Oxford’s viral vector manufacturing expertise.
“Accessing Homology Medicines’ unique AAV capabilities is a major advancement in Oxford Biomedica’s goal to become an innovative global viral vector leader that provides solutions to Cell and Gene Therapy (C>) Biotech and biopharma companies for their process development and manufacturing needs across key viral vectors,” noted Dr. Roch Doliveux, the CEO of Oxford BioMedica, in an earlier statement.
The U.K. firm is dropping $130 million in cash to support Homology’s current clinical programs and is investing a further $50 million to support the new company.
