Would you use sequential CDK 4/6 inhibitors in HR-positive metastatic breast CA in successive lines of therapy?  

There is no preclinical or clinical data to support this approach at this time. I would not use sequential therapy in the absence of data. Several studies are ongoing to evaluate whether continued suppression of this pathway in the face of disease progression benefits patients. Until those studies h...

It is unclear what to do after progression on CDK4/6- endocrine therapy combination therapy. One option—without much data so far—might be to change the backbone of endocrine therapy only, for example, from an AI to fulvestrant while continuing CDK4/6 inhibition beyond progression. Anothe...

For certain select patients, using sequential CDK4/6 inhibitors can certainly be considered. However, the data supporting this strategy are currently too limited to recommend this as the standard approach. The strongest argument for offering sequential CDK4/6 inhibitors comes from the randomized Pha...

While we wait for the result from the postMONARCH study, we do not have randomized phase 3 data on this topic and thus, cannot be considered standard of care practice in general. However, I have used this strategy (sequential CDK4/6i) in a few selected patients after careful discussion of available ...

Yes, sequential use of CDK4/6i therapy is supported by data from the MAINTAIN Trial. This was a randomized phase II trial of endocrine therapy (ET) with ribociclib after progression on a CDK4/6i. Most (86.5%) of the patients enrolled in the trial had prior palbociclib. There was a statistically sign...