4D Molecular Therapeutics has reported positive safety data from the Phase I dose escalation clinical trial of its rare eye disease drug candidate, 4D-110, to treat choroideremia.

Initial safety results of the drug candidate’s two dose levels showed favourable tolerability without any dose-limiting toxicity.

However, 4D Molecular partner Roche has decided to terminate their collaboration and licence agreement covering 4D-110. The termination is effective as of 16 September 2021.

Roche also requested the conclusion of the 4D-110 trial for advanced choroideremia based on its review of a change in the risk-benefit profile.

This move will return full 4D-110 rights to 4D Molecular, which intends to continue the development of the drug candidate.

4D Molecular plans to submit the safety and efficacy findings from the completed Phase I trial and a new study protocol to the US Food and Drug Administration soon.

With enrolment already complete, the Roche-funded 4D-110 trial will be concluded, and previously treated patients will be moved to a 4D Molecular-sponsored long-term follow-up study.

4D Molecular Therapeutics Clinical Research senior vice-president and Clinical Ophthalmology head Robert Kim said: “We plan to conclude the Roche-funded clinical trial under the collaboration and subsequently transfer previously treated patients onto a long-term follow-up study to continue monitoring biological activity endpoints and safety.

“We are committed to designing and initiating the next 4D-110 clinical trial, including treatment of earlier-stage patients, as soon as possible after reviewing the clinical data with our investigators and the FDA.”

The company also reported that its other rare disease ophthalmology candidate, 4D-125, was well-tolerated and did not cause any dose-limiting toxicity, according to initial safety findings in the Phase I part of a Phase I/II trial in X-linked retinitis pigmentosa (XLRP) patients.

Initial biologic activity data of both 4D-110 and 4D-125 are set to be available in the fourth quarter of this year.