Solid tumors of other primary organ sites frequently metastasize to the choroid due to its highly vascularized structure and slow rate of perfusion. Metastases to the choroid are the most common intraocular malignancy, with an approximate annual incidence of 20,000 patients in the US and Europe. When standard systemic antineoplastic therapy is ineffective in treating choroidal metastases, the available local therapies are photodynamic therapy or external beam radiotherapy, which are both associated with significant treatment burden and morbidity.

The tumor selectivity of bel-sar is driven by binding to tumor-associated HSPGs which are broadly expressed across multiple solid tumor types. Nonclinical studies have demonstrated high potency against breast, lung, gastrointestinal and pancreatic tumor cells, among others, making it a promising treatment option for choroidal metastases regardless of primary cancer origin.

Aura is studying bel-sar in a Phase 2 dose-escalation study in patients with choroidal metastases.