PTC has never created any kind of CMMI Solution specifically. From what I can gather online, Capability Maturity Model Integration (CMMI) is a specific type of philosophy and business practice regulation similar to ISO, SPICE, etc.
I imagine that because Integrity is so customizable, a workflow data model could be built within Integrity which is CMMI-compliant. However, that would be a completely custom implementation and an engagement with GS or a Partner would be needed.
