Aldeyra Therapeutics has commenced a Phase II clinical trial of its investigational drug, ADX-2191 (intravitreal methotrexate 0.8%), to treat retinitis pigmentosa (RP)

ADX-2191 is methotrexate’s intravitreal formulation. Methotrexate is a compound that hinders cellular replication and activation. 

The open-label, single-centre trial will analyse the safety and tolerability of ADX-2191 to treat RP patients with rhodopsin gene mutations, including the P23H gene mutation. 

Being carried out at Duke University Medical Center in Durham, North Carolina, US the trial is anticipated to enrol eight subjects. 

Four subjects each will be given monthly and twice-monthly intravitreal doses of ADX-2191, respectively, for three months. 

The company anticipates top-line data from the trial in the second half of this year.

Aldeyra Therapeutics president and CEO Todd Brady said: “ADX-2191 represents a novel approach for the treatment of patients with retinitis pigmentosa, an incurable, sight-threatening condition. 

“We are excited about the opportunity to advance our ADX-2191 retinal programme across a variety of rare and underserved diseases and look forward to reporting the top-line results of the retinitis pigmentosa Phase II clinical trial in the second half of this year.”

The US Food and Drug Administration granted orphan drug designation to ADX-2191 for RP treatment. 

Apart from RP, the investigational drug is being developed to prevent proliferative vitreoretinopathy and treat primary vitreoretinal lymphoma. 

A clinical category of rare genetic eye diseases, RP is characterised by retinal cell death and loss of vision, with no therapies currently approved to treat the condition.

In December last year, the company reported that its new experimental 0.25% reproxalap ophthalmic solution failed to meet the primary goal in the Phase III TRANQUILITY trial for dry eye disease.