Axiclinib Implant Shows Promise for Maintaining Vision in Wet AMD Patients

DENVER – A new implant that slowly releases medication into the eye may help people with a common form of age-related vision loss keep their sight longer than standard treatments, according to a study presented at a major eye research conference.

Researchers compared the axitinib implant, called OTX-TKI, with the standard drug aflibercept (brand name Eylea) in patients with wet age-related macular degeneration (AMD), also known as neovascular AMD. This condition causes abnormal blood vessels to grow under the retina, leading to vision loss if untreated.

The study found that among patients who started with good vision, 74.1% of those receiving the implant still had that same level of vision after 36 weeks. In comparison, only 55.8% of patients taking standard-dose aflibercept maintained their vision. That advantage continued through 52 weeks, with 65.9% of implant patients keeping their vision versus 44.2% in the aflibercept group.

Three out of four patients (75.5%) who got the implant did not need any extra treatment to control their disease by 36 weeks. That number was 56.4% for those taking aflibercept. Both groups showed similar improvements in best-corrected visual acuity (BCVA) and central subfield thickness (CST), which measures swelling in the retina.

Dr. Patricio G. Schlottmann of the Charles Ophthalmic Center in Buenos Aires presented the findings at the Association for Research in Vision and Ophthalmology meeting. He noted that the implant helped patients maintain early gains in vision and eye structure better than standard therapy.

“This is the first trial to demonstrate durability of more than 9 months,” Schlottmann said. “This is unmatched durability. Anatomic stability was achieved to sustain disease control, and the treatment was very well tolerated.”

The patients in this study had relatively good vision at the start, averaging about 70 letters on an eye chart. For comparison, 85 letters equals perfect 20/20 vision. “After two loading doses, they reached a visual acuity of 80,” Schlottmann explained. “Let me remind you that 85 is full 20/20 vision, so these patients had very little room to keep gaining vision.”

Because these patients started with good vision, maintaining it is more meaningful than in studies where patients begin with worse vision and have more room for improvement.

During a question-and-answer session after the presentation, an audience member asked about the roughly 25% of patients who did not maintain their vision with the implant. Schlottmann said doctors could identify these patients early as needing extra treatment. “We don’t have any biomarkers if that is what you are looking for,” he added. “We have a massive amount of data, and we can look into that.”

The OTX-TKI implant uses a special hydrogel delivery system. It contains a bioresorbable polymer matrix combined with axitinib, a drug that blocks vascular endothelial growth factor (VEGF). Oral axitinib (sold as Inlyta) is already FDA-approved for kidney cancer. The implant is designed to release the drug slowly inside the eye and then dissolve completely. A previous phase I study showed the implant reduced the need for injections by 90%.

The phase III SOL-1 trial randomly assigned patients to receive either the axitinib implant or aflibercept 2 mg. Eligible patients had never been treated for choroidal neovascularization linked to AMD. They needed a BCVA of at least 54 letters (about 20/80) and a CST of 500 µm or less. All patients first received two doses of aflibercept four weeks apart. Only those who improved by 10 or more letters or reached 84 letters with a CST of 350 µm or less were then randomized.

The main goal was maintaining vision at 36 weeks, defined as losing fewer than 15 letters from the starting point. Follow-up continued to 52 weeks. Patients received rescue treatment if their vision dropped by 15 or more letters or if they developed new bleeding in the macula. The analysis included 344 randomized patients, with 328 completing the full 52 weeks.

At the start, patients averaged about 70 letters of vision and a CST of 303 µm. By the time of randomization, vision averaged 80 letters and CST measured between 219 and 227 µm.

Significantly more patients in the implant group met the primary endpoint, with an absolute difference of almost 20% (P =0.0006). At 52 weeks, 66% of implant patients maintained their vision compared with 44% of aflibercept patients (P <0.0001). Three-fourths of implant patients needed no rescue treatment by 36 weeks versus 56% of the aflibercept group (P =0.0006).Anatomical improvements also held up better with the implant. CST averaged 219 µm at randomization and 238 µm at 36 weeks. In the control group, those numbers were 227 µm and 258 µm.Safety was similar between the groups. About 11% to 12% of patients in each arm had at least one non-ocular serious adverse event. Fewer than 1% of patients in either group had serious eye-related side effects in the treated eye.

Source: MedPage Today