For a patient with MM progressing on a daratumumab-based regimen, is it preferable to entirely switch drug class or is another monoclonal antibody such as isatuximab an acceptable next step?  

Class switch approach appears to give better disease control, isatuximab does not have activity in daratumumab refractory patients (Mikhael et al., PMID 33980831).

I recommend switching drug classes after progression on daratumumab.Isatuximab, like daratumumab, is a monoclonal antibody against CD38. It has been shown to be ineffective after progression on daratumumab. Mikhael et al, PMID 33980831. While elotuzumab is a monoclonal antibody with a different targ...

Agreed with the above two answers. In case the converse question ever comes up (daratumumab in isatuximab-exposed patients), it's also worth noting that a recent update from the ICARIA-MM trial at the 2021 ASCO meeting showed a 14% overall response rate (ORR) to daratumumab monotherapy and 31% ORR w...

From personal experience, and also publication noted earlier, no benefit with Isatuximab after Daratumumab or possibly vice versa. May have some benefit if >6 mos since last exposure to either drug. Options here: If on daratumumab alone and monthly, can actually change back to every 2 weeks an...

Unfortunately, optimal treatment after daratumumab failure remains unknown, because most of the phase III trials including pomalidomide/dexamethasone or carfilzomib/dexamethasone backbones did not enroll patients refractory to anti-CD38 monoclonal antibodies. In patients not previously treated with ...