A 4 week trial is indicative only - and a positive result...

A 4 week trial is indicative only - and a positive result (relative to placebo) is an indicator that further work is worthwhile.

I suspect that some people were hoping for a higher success rate (hence the "sell off")- but that's not really the way short term indicator trials works. Anyone involved in product formulation and R&D would be aware of that.

This trial proves the active ingredient is beneficial to the condition - R&D will now proceed to improve efficacy and tighten the formulation.

Further, as the treatment is targeted at a chronic, rather than acute, condition - the focus will be on long term improvement and tolerance. So while an improvement was sighted in 34% of the test group over four weeks, this could easily increase substantially with an "improved" formulation over a longer trial period.