Follow up reports on non-topline data are usually very comprehensive final reports, often presented at scientific conferences. You prefer they did a quick PR on OM duration and are assuming that if they don't it means the data is bad. That is poor reasoning, and pessimistic. I would rather light a candle than curse your darkness.
Fortunately what you think about what is easy or not doesn't matter. They will provide the secondary end points when they are available in the weeks come per the PR.
So what was reported was that 30 to 40 % of the participants did not endure severe OM, which means there is No duration time to report for those patients.