Homology Medicines is now able to enroll patients in its HMI-102 gene therapy trial—but is choosing not to. Having persuaded the FDA to lift the clinical hold in June, the biotech has now paused enrollment in the phenylketonuria (PKU) study to free up cash for a gene editing trial in the same population.
Massachusetts-based Homology began the phase 1/2 study of HMI-102 in 2019, putting it on course to wrap up the clinical trial next year. The FDA held back the study by a few months this year over elevated liver function tests, but Homology soon got the clinical trial going again by adding a steroid-sparing immunosuppressive regimen and a shorter course of steroids to the protocol.
Now, two months after getting the hold lifted, Homology has voluntarily paused enrollment for financial reasons. Homology saw biologic activity, including falls in serum phenylalanine and increases in tyrosine, in recipients of the gene therapy but is still pausing the pheNIX study to prioritize the pheEDIT study of HMI-103. The switch is intended to extend Homology’s cash runway and produce some fresh data.
“Prioritization offers potential to generate data, which includes a new immunosuppression regimen with a shorter course of steroids and a T-cell inhibitor as part of the pheEDIT protocol, sooner than would be possible to resume enrollment at pheNIX trial sites,” the company wrote in its second-quarter results.
As a result of diverting resources to pheEDIT, Homology now expects its cash reserves, which totaled $225.5 million at the end of June, to last into the fourth quarter of 2024. The biotech previously advised investors that its cash would keep the lights on into the second half of 2024.
The phase 1 pheEDIT study in adults with PKU kicked off in June to evaluate HMI-103, a nuclease-free gene editing candidate designed to provide permanent DNA correction for PKU by replacing at least one disease-causing allele with a normal gene sequence in edited cells.