Something like this at trial is going to come down to the...

Something like this at trial is going to come down to the scientists who testify. CSS had poor survival rates under their feed, then switched to a competitor & suddenly they had good survival rates. So as long as that is all that CSS changed it should be a slam dunk at trial with the right independent witnesses.
If the interlocutory is favourable then Gibsons would be crazy to continue to go to trial unless they are in a situation where they financially can't afford to settlle, don't have insurance cover & have nothing to lose by going to trial as they're bankrupt unless they win either way.