New myeloma drugs improve response and extend survival

DR HENRY In summary then, this would be, in 2017, off-protocol while the data is pending: it’s reasonable to get a deep induction response, collect stem cells, have a discussion with the patient, and then consider high-dose therapy or not.

DR ANDERSON Yes. I think it’s reasonable to discuss it. We need to be open and honest with patients that the standard of care remains transplant, that you incorporate novel treatments before the transplant and novel treatments as maintenance after the transplant. The happy news is that the outcome, especially for patients who have standard-risk myeloma, is at least a decade or longer progression-free survival. It’s an optimistic picture. The data in terms of transplant being needed or not, will come within the next several years.

For now, it is a standard of care to use 1 high-dose melphalan and stem-cell transplant in this setting. I will add into our discussion with patients – besides the opportunity to harvest stem cells and think about whether one needs to do a transplant early on or not – is the issue of toxicity. High-dose melphalan by itself has a small but real secondary incidence of cancer, myelodysplasia, or leukemia. If one uses lenalidomide maintenance after melphalan transplantation treatment, that risk of secondary cancer is slightly increased.

In my experience, if patients have achieved a complete response with induction therapy only, it’s not unreasonable to offer early transplant and be clear that’s the standard of care. The alternative is maintenance with lenalidomide, knowing once the stem cells have been harvested, that transplantation can be an option to treat relapsed myeloma. We have many other options available as well. Time will tell in terms of the ongoing randomized trials as to whether transplant remains central to our treatment paradigm.

DR HENRY This leads us to our second patient. Here we have an older man of 74 years. He’s a professional piano player, so we want to try to avoid peripheral neuropathy in him. He has some mild renal insufficiency and some coronary artery disease, so he’s deemed transplant-ineligible. He has IgG kappa myeloma, and he’s brand new. What would you consider to be options for him for treatment?

DR ANDERSON This brings up the issue of a transplant-ineligible patient. He has significant comorbidity that would make transplantation an increased risk. What we would recommend in such a patient is still triplet induction therapy incorporating novel agents (Figure 1). Lenalidomide, the immunomodulatory drug, can safely be given in the context of neuropathy because it does not cause significant neuropathy. It would need to be dose modified, depending on the degree of renal insufficiency. We would recommend also including proteasome inhibitors. Bortezomib, the first-generation proteasome inhibitor, would be contraindicated because it does have a small but real attendant neuropathy. If, however, it is given weekly and subcutaneously, the risk of attendant neuropathy is quite low. In this patient, therefore, one could start with lenalidomide and bortezomib weekly and subcutaneously,^1,2 with a very early and vigilant follow-up for the earliest signs of neuropathy, so as not to allow it to develop and compromise his career.

Alternatively, one could use a proteasome inhibitor that does not have attendant neuropathy. Carfilzomib, the second-generation proteasome inhibitor, does not have neuropathy.⁹ But we would need to have caution here, because this patient has a history of coronary artery disease, and carfilzomib has a very small, but real, incidence of cardiac toxicity so would need to be used judiciously in this setting. The third proteasome inhibitor, ixazomib, is the next-generation bortezomib-class proteasome inhibitor, and it’s oral.¹⁰ It has less neuropathy than does bortezomib, so in my view is a very realistic option for him together with lenalidomide. It does have a small incidence of neuropathy, so close monitoring for neuropathy would be indicated. We could use lenalidomide–dexamethasone as a doublet and avoid neuropathy,¹¹ but usually doublets are reserved only for frail patients.

My recommendation, therefore, would be RVD with the bortezomib weekly or subcutaneously, or alternatively, lenalidomide, ixazomib, dexamethasone as an all-oral regimen as induction therapy. In my view, this 74-year-old patient with comorbidity is not a transplant candidate. However, one can be very optimistic with this patient. The likelihood that he could have myeloma as a chronic illness and die from something else is quite high. Initial induction triplet therapy would achieve a very high response extent and frequency. The durability would be long, especially with lenalidomide maintenance if it’s standard-risk myeloma or lenalidomide and a proteasome inhibitor, probably ixazomib in this setting, if he were to have high-risk myeloma.

If myeloma relapses, then there are many options that could be used in this patient and achieve years of progression-free and overall survival. Indeed, he is 74 years old and will respond very well to induction triplet therapy, with many years’ duration of response due to continuous lenalidomide or lenalidomide and proteasome inhibitor maintenance. Then there are many effective options to treat relapsed therapy using triplet novel agents. Therefore, his lifespan is unlikely to be shortened by multiple myeloma.