He doesn't refer to them as CR's - he clearly refers to them as CR's with respect to two of the criteria. That's much more precise (and stronger for the drug) in this case than referring to them as PR's.
The abstract is written in what I would term abstractese rather than in English. In abstractese, it's non-ambiguous and clear. Only if you try to read the language out of context, assuming it is language from a paper rather than an abstract, is there any issue here at all.