Clearside Biomedical reports positive safety results of cohort 1 trial of CLS-AX for nAMD

Clearside Biomedical, Inc. reported today positive safety results from Cohort 1 of its ongoing OASIS phase1/2a clinical trial of CLS-AX (axitinib injectable suspension)for the treatment of neovascular age-related macular degeneration (wet AMD).

CLS-AX was delivered by suprachoroidal injection using Clearside's SCS Microinjector® in six patients with nAMD, according to a company news release.

With primary endpoints being achieved in Cohort 1, the initial lowest planned dose of CLS-AX (0.03 mg) was well-tolerated and had no serious adverse events or drug-related treatment emergent adverse events were observed during the study.

The company reported patients showed no signs of inflammation, no vasculitis, no IOP safety signals, no dispersion of drug into the vitreous, and no other drug-related adverse events.

The average age of Cohort 1 participants was 82 years old. All patients had previously undergone anti-VEGF treatment by way of a number of injections of standard-of-care prior to the start of the OASIS trial, according to the company.

The mean number of previous anti-VEGF treatments within 1 year and up to 3 years prior to the trial was 9.0 injections and 22.5 injections, respectively, the company reported.

Additionally, all patients enrolled in the trial underwent diagnostic imaging at screening, followed by masked reading center confirmation of persistent active disease.

The mean central subfield thickness of the macula was 231 µm (range 208 - 294 µm), while the mean baseline best corrected visual acuity (BCVA) score at the start of the trial was 59.0 (range 29 - 74), according to the company.

At the initial visit of Cohort 1, six of the treatment-experienced patients in the first cohort were given a standard-of-care, single intravitreal injection of 2 mg aflibercept.

After one month, the mean BCVA score for all patients was reported as stable, changing only by -0.2 letters, the company reported. Patients then receive a single suprachoroidal dose of 0.03 mg CLS-AX.

According to the company, one month after receiving CLS-AX, five of six patients showed improvement in BCVA, with each individual gaining four or more letters. The mean BCVA score of all patients increased by +4.6 letters (p=0.029, post hoc, unadjusted).

The company reported that, overall, no patients in Cohort 1 required additional treatment with aflibercept at the one-month visit following administration of CLS-AX: two patients went three months after CLS-AX administration without additional treatment with aflibercept and BCVA improved by 5 and 7 ETDRS letters for them; four patients received additional treatment with aflibercept at the two-month visit post-CLS-AX.

For all participants, the mean CST was stable within 50 µm at both one month following injection of 2 mg aflibercept as well as one month after injection of 0.03 mg CLS-AX, the company stated.

After review of the data, the trial's safety monitoring committee has determined it will advance to Cohort 2.

Patient screening for Cohort 2 with a dose of 0.1 mg CLS-AX will begin this month, with completion of the four-month trial period expected to commence by end of this year, the company reported.

References

1. Clearside Biomedical Announces Positive Safety Results from Cohort 1 of OASIS Phase 1/2a Clinical Trial of CLS-AX (axitinib injectable suspension) for the Treatment of Wet AMD. Available at: https://ir.clearsidebio.com/news-releases/news-release-details/clearside-biomedical-announces-positive-safety-results-cohort-1. Accessed 6/15/21.