Ann: 2023 Annual Report to shareholders, page-167

Yes, Opthea’s pivotal trials are very large, but they were never going to be in ~100 patients, such as can be found in some rare disease trials.

Opthea's Phase 3 trails are testing sozinibercept in combination with the two leading wet AMD therapies, Lucentis and Eylea.

A comparison with patient numbers in the Phase 3 trials used for the approval of these two drugs shows that Lucentis was assessed in three trials with a total of 1,323 patients and Eylea in two trials with a total of 2,412 patients.

Additionally. Opthea’s pivotal trials are more complex that those conducted for Lucentis and Eylea in wet AMD. Opthea is not only testing its drug in combination with two different drugs in two different trials, it’s also assessing two different dosing regimens; thus 3 arms are required in each trial.

Each trial has 990 patients, with 330 in each arm. The trials are designed for ~90% power and 5% type 1 error rate.

Can’t help beyond that as my knowledge and understanding of clinical trial design and statistics is very basic – perhaps someone with more knowledge might be able to help on the OPT forum?