Clearside Biomedical, Inc announced plans for its phase 2b study ODYSSEY, which will assess CLS-AX, administered by suprachoroidal injection via the company’s SCS Microinjector, for the treatment of neovascular age-related macular degeneration (wet AMD).
Tell me about CLS-AX.
CLS-AX (axitinib injectable suspension) is a tyrosine kinase inhibitor (TKI) currently approved to treat renal cell cancer. It achieves pan-VEGF blockade by directly inhibiting VEGF receptors-1, -2, and -3 with high potency and specificity.
With suprachoroidal administration of axitinib, there is the potential to achieve prolonged duration and targeted delivery to affected tissue layers.
Any prior clinical data on it?
Indeed there is. The phase 2b trial plans come following positive data from Clearside’s OASIS phase 1/2a study in November 2022 as well as positive 6-month data from an extension trial in February 2022.
Click here and here for those details.
Now talk about this ODYSSEY trial.
The randomized, double-masked, parallel-group, active-controlled, multicenter phase 2b trial will enroll 60 patients diagnosed with wet AMD and randomized 2:1 between the CLS-AX and aflibercept arms.
What are the participant criteria?
All patients must have been diagnosed with wet AMD within at least 36 months of screening for the study, and must have a history of two to 4 anti-vascular endothelial growth factor (anti-VEGF) during the 6 months prior to screening as well as a history of response to anti-VEGFt treatment for the disease.
Further, they require a best-corrected visual acuity (BCVA) of 20 to 80 letters and a reading center confirmation of persistent active disease.
How about the doses?
Forty patients will receive CLS-AX and 20 will be administered aflibercept; participants in both arms will receive three 2 mg loading doses of aflibercept while participants in the CLS-AX arm will be administered one loading dose of 1.0 mg CLS-AX at the same visit as the baseline dose of aflibercept.
After that, patients will receive (in the CLS-AX arm) CLS-AX at least every 24 weeks, unless disease activity requires a more frequent basis. For patients in the aflibercept arm, they will be administered aflibercept on a fixed-dosing regimen every 8 weeks.
What’s being assessed?
The primary outcome measure includes the mean change in BCVA from baseline to Week 36; secondary outcome measures include other changes in visual function / ocular anatomy (such as central subfield thickness [CST]), a need for additional treatment (weekly disease assessments will be conducted in both arms at Week 12 through Week 32), and treatment burdens (measured via total injections throughout the trial).
So what’s next?
Clearside is planning to open enrollment for the ODYSSEY trial at U.S. sites across the country in Q2 2023. The company expects to report on topline results by Q3 2024.