How to access the patient-derived xenografts (PDXs) repository?
I already see for links when I try to search. Take a look at them below. Also if you can be precise about kind of data are you trying to find, it would be better

https://pdmr.cancer.gov/

http://cdt.northwestern.edu/news/patient-derived-xenograft-repository-now-available-researchers

http://www.epo-berlin.com/epo-tumor-models-xenografts.html

http://www.proxe.org/

http://data-analysis.charite.de/care/

http://www.oasis-genomics.org/

http://www.cbioportal.org/

Hope one of these above will serve the purpose for you.

Update: added some more links that might serve. As for the Cellminer the last update was 2012.