Axitinib Intravitreal Implant Shows Promise for Wet AMD

At the American Academy of Ophthalmology (AAO) annual meeting, new data were presented from a 7-month analysis on OTX-TKI, an axitinib (Inlyta) intravitreal implant being evaluated for the treatment of wet age-related macular degeneration (AMD).

In this exclusive MedPage Today video, presenting author Dilsher Dhoot, MD, an ophthalmologist at the California Retina Consultants, discusses the analysis.

Following is a transcript of his remarks:

It was my pleasure to present, at the subspecialty day, the interim safety and efficacy data analysis from the axitinib hydrogel implant, also known as OTX-TKI, for patients with neovascular macular degeneration. This was an interim 7-month analysis.

And so in this study we looked specifically at OTX-TKI, which is a combination of a hydrogel delivery platform, specifically a proprietary bioresorbable polymer matrix of polyethylene glycol combined with a tyrosine kinase inhibitor. And so this tyrosine kinase inhibitor was axitinib, which is a highly selective inhibitor of all VEGF and PDGF receptors, and has a high affinity and a low solubility compared to other ocular TKIs that you may have heard of that are being investigated in the retina space.

This is a single implant that’s completely bioresorbable. Its target release is 6 to 9 months, and it’s administered via a 25-gauge or smaller needle.

And so this phase I U.S. trial took patients who had active but controlled neovascular AMD on anti-VEGF medications and randomized them in a 3:1 fashion to OTX-TKI versus aflibercept [Eylea]. And so aflibercept was the control and it was dosed every 8 weeks. Patients received OTX-TKI at baseline, and then 1 month later received a single aflibercept, and thereafter received sham injections every 8 weeks.

Now, patients were allowed to receive rescue in the OTX-TKI arm, and the rescue criteria were standard rescue criteria for wet macular degeneration, which had basically visual acuity or anatomic criteria that would allow for rescue, new macular hemorrhage would allow for rescue. And then, finally, investigator discretion would allow for rescue.

And so 21 patients in total were included in this trial, 16 patients in the OTX-TKI arm and five patients in the aflibercept arm. Their baseline characteristics were well balanced, and the efficacy data was very interesting. OTX-TKI demonstrated a reduction in the treatment burden. We presented a nice swimmer’s lane plot during the presentation, which showed a relatively high burden of treatment in these wet AMD patients prior to receiving OTX-TKI. And then following the TKI administration, the burden dramatically reduced.

Only five rescue injections were given in four patients, and these were actually all given at investigator discretion. And so none of the patients actually met the … visual acuity criteria.

And so, in total, 80% of subjects were rescue-free up to 6 months; 73% of subjects were rescue-free up to 7 months, which is quite impressive.

There was sustained and a stable effect with the single OTX-TKI implant in terms of visual acuity and anatomy compared to the aflibercept dosed every 8 weeks. And in terms of safety, the drug seemed to be generally well-tolerated with kind of an expected safety profile. There were no reports of any systemic or ocular serious adverse events. There were mild adverse events noted that are typical for intravitreal injections. There was a single case of endophthalmitis, which actually followed the aflibercept given at 1 month in the OTX-TKI group. And this was 6 days post-aflibercept injection, and the patient did quite well after receiving antibiotics. So, generally safe.

In summary, the data showed that, efficacy-wise, we saw great durability, 80% of subjects rescue-free at 6 months and there was stable and sustained visual acuity improvements, and clinically meaningful reduction in the burden of treatment at both 6 and 7 months with OTX-TKI. The study’s ongoing, and so we look forward to the 1-year data, which will be presented next year.