BETA - When is the ideal time to collect stem cells? Do myeloma cells get included in the stem cell collection and infusion during ASCT?

When is the ideal time to collect stem cells, and how much treatment should you do first? Ideally, we want to get the disease burden down before collecting the stem cells. But since we do harvest peripheral blood stem cells, when we give patients growth factors, myeloma cells don't always come out into the blood very well. So as long as we have gotten what we call a partial remission, we think it's a good time to collect these stem cells. Sometimes when you get further therapy, it becomes harder to coax the bone marrow stem cells to come out of the bone marrow into the blood because patients have seen more chemotherapy. So the ideal time, we think, is about three to four rounds of standard induction therapy. At this time, that's with typically a combination of three drugs. But every case is a little bit different. And so we have had patients who've had more therapy than that, and we've successfully been able to collect stem cells. And some patients require just three cycles, and that's good enough for them. So a little bit of variability, but somewhere around three to four is what is our standard practice. All the data that I cited so far that stem cell transplant is associated with deeper responses, higher rate of complete remission, higher rate of MRD negative disease, higher rate of progression-free survival, better overall survival. All these studies were done with whatever the available induction treatments were. And most of the patients get finite number between four to six cycles. Now we have more effective treatments where patients actually achieve a complete remission, a significant proportion. There were times where fewer than 10% would actually achieve a complete remission, and we would still harvest their stem cells and do the transplant. So the data support that even with the presence of residual disease in the bone marrow, you can safely do this procedure and achieve a deep remission. In general, a stem cell collection is something that's done early in the treatment natural history of multiple myeloma. Our practice is to perform stem cell collection after four or six cycles of induction or initial therapy. One can collect stem cells later than that, but it becomes more difficult sometimes and also the efficiency of the collection and perhaps even the quality of the stem cells may be affected in the sense that after a prolonged period of treatment, the stem cells and the cells may get damaged by the treatment. Is there any reason to continue treatment beyond four to six cycles of therapy to get an even deeper response before transplant? Of course, we would like to see as deep a remission as possible, but people have looked at that in analyses from registry and data from different centers that is there any benefit to continuing treatment for longer period of time until patient achieves the complete remission? The analyses showed that even patients who were not able to achieve even a partial remission, they divided them into two groups. Half of them got additional treatment to deepen the response and the other half who went on to get transplant, whatever their response level was. And what they showed was that those who got additional treatment and got deeper response did as well as the ones who did not. So at this point, the data support that you give finite number of cycles, four to six cycles, most of the patients in this DNA achieve a partial remission and then we can go on to harvest their stem cells and proceed to transplant. If we continue to give treatment, there are no data that we are actually going to help those patients. And in some ways we may hurt more treatment means difficulty in collecting an adequate number of stem cells. Sometimes it may adversely affect the quality of stem cells. And as we all know that these treatments are not without side effects. So by continuing to treat patients, we may actually cause more side effects and perhaps increase the morbidities. So it's perfectly safe to do finite number of treatments. And as long as patient is responding, harvest the stem cells and proceed to transfer.