New myeloma drugs improve response and extend survival

DR HENRY It’s so incredible compared with what it was when I trained. The next patient, a 45-year-old woman with IgG lambda myeloma, has had RVD induction and responded. She had lenalidomide maintenance, but then she progressed, and she got her stem-cell transplant, and she’s progressing after that. I guess we’re looking here to fold in some of the newer agents. How you would you do that in this patient?DR ANDERSON Yes. I think one of the most remarkable and exciting developments with myeloma is the rapid approval of the novel classes of agents that I mentioned earlier – the proteasome inhibitors, the immunomodulatory drugs, the HDAC inhibitor, and the monoclonal antibodies.¹ They’re particularly relevant in a patient such as this one, whose myeloma has relapsed after what would be considered standard therapy for a young person with standard-risk myeloma. This patient had RVD and maintenance therapy, and then progressed. The transplant was given for relapsed myeloma. The opportunity to use stem-cell transplant in patients when myeloma becomes active after maintenance should not be forgotten as it can be very effective. In all the trials done to date in which early versus late transplant are compared, there have been similar outcomes. Therefore, if the transplant isn’t done early, don’t forget that it’s an option at the time the myeloma progresses. I do want to mention, that there are lots of options for relapsed myeloma (Figures 3 and 4). I mentioned RVD or CyBorD as initial triplet therapies.^2-4 In North America, those are the 2 most common regimens. If myeloma then relapses and is resistant to RVD or to CyBorD, then we need to identify alternatives.

We also need to think about the comorbidities in the patient – issues such as age, neuropathy, presence of renal dysfunction, and other clinical factors. And we need to think about what treatment they’ve had in the past. This patient has had RVD, maintenance with lenalidomide, and a stem-cell transplant. We can offer patients a variety of therapies, but in the context of resistance to the first-generation proteasome inhibitor bortezomib and the first-generation immunomodulatory drug lenalidomide, we would strongly recommend the second-generation immunomodulatory drug pomalidomide¹² together with a second-generation proteasome inhibitor, be that carfilzomib¹³ or ixazomib.¹⁴ When one uses the second-generation IMiDs and proteasome inhibitors together, there’s a very high frequency of response in the order of 70%-80%, which lasts years.

Besides carfilzomib and ixazomib proteasome inhibitors, we also have elotuzumab and daratumumab, the monoclonal antibodies.^15-17 These agents have been FDA approved to treat patients such as this one who has had 1-3 previous therapies for their myeloma. All of them have been approved in randomized phase 3 trials compared with lenalidomide-dexamethasone in the control arm.^13-15,17 They’ve all been found to be superior. Although lenalidomide-dexamethasone combined with daratumumab, ixazomib, elotuzumab, or carfilzomib is superior to lenalidomide in relapsed myeloma, the situation in North America, as in this patient, is usually that patients have had lenalidomide-dexamethasone as part of their initial treatment and their myeloma is refractory to lenalidomide.

Hence, we recommend, that we go to the second-generation pomalidomide and second-generation proteasome inhibitors, either carfilzomib or ixazomib. Having said that, the treatment paradigm is evolving. For example, the monoclonal antibody daratumumab was initially approved by the FDA in multiply relapsed disease as a single agent because it achieves a 30% response rate.¹⁶ It now has been moved earlier into the first relapse of multiple myeloma, where it achieves much higher response rates when combined with lenalidomide–dexamethasone or combined with bortezomib–dexamethasone.^17,18 Response rates of 70%-80% can be achieved, including minimal residual disease negative complete responses.

Today, in a patient who has had RVD transplant and myeloma has returned, we would recommend second-generation IMiDs, pomalidomide, and second-generation proteasome inhibitors, either carfilzomib or ixazomib. Data for daratumumab combined with lenalidomide-dexamethasone or with bortezomib-dexamethasone, look very promising. We need, however, to see more experience of daratumumab together with lenalidomide-dexamethasone or daratumumab together with bortezomib-dexamethasone in patients whose myeloma is refractory to RVD, that is, patients whose myeloma has returned after RVD induction treatment. Of note, pomalidomide, dexamethasone, and daratumumab have just been approved by the FDA and may also be active even in myeloma recurring after RVD treatment.¹⁹

Daratumumab in combination will be moving earlier and earlier and may be appropriate to treat the first relapse. I do want to stress, however, that at present I save daratumumab for the second or greater relapse. Daratumumab is active even when relapse occurs after treatment with second-generation IMiDs and proteasome inhibitors.