P-170: Transplant related morbidities with Melphalan as conditioning regimen for myeloma autotransplants

Background Melphalan as high dose therapy (HDT) is a proven effective conditioning regimen for patients undergoing myeloma autotransplants and is associated with known peri-transplant toxicities that warrant a discussion with patients. Efforts to optimize supportive care have resulted in significant decline in transplant related morbidities and mortality. In this context, we have reviewed the observed toxicities among patients receiving autotransplants in the recent years with an intent to deliver consistency in informing patients of the known toxicities. Methods We conducted a retrospective analysis of myeloma patients undergoing autologous stem cell transplant over a two-year period. Demographic and outcomes data for the patients were obtained from our IRB approved myeloma database and responses were evaluated per IMWG Uniform Response Criteria. Fisher’s exact and Cochran-Mante-Haenszel tests were used when groups were compared. Results Of the 395 patients that underwent autotransplants 308 patients received a dose of 200 mg/m2 (Mel200) and 87 received 140 mg/m2 (Mel140). Median age of the patients was 62 years (range, 17-78). Impressively, African American patients comprised of 41.5% of the entire cohort. Relevant comorbidities prior to transplant include hypertension (62%), renal failure (5%), coronary artery disease (5%) and h/o atrial fibrillation (4%). 11% of patients had KPS ≤70, median pretransplant EF was 55% (30-86%), and DLCO corrected was 87% (30-156). Median time for neutrophil engraftment, platelet engraftment and LOS were 14 (12-24), 14 (11-21), 15 (7-53) days respectively. While peri-transplant, neutropenic fevers were seen in 67% of the patients, majority were of non-infectious nature. Documented bacteremia was seen in 13% of patients, clostridium difficile infection in 8%, respiratory infections in 5%, and other infections were seen in 2% (cellulitis- 1% and UTI -1%). Any grade mucositis was seen in 31% and grade 3 mucositis in 7%. Atrial fibrillation was seen in 5% and renal failure in 4%. Readmission rates were 5%, median time to readmission was 4 days (range, 1-20). Transplant related mortality at the 30-day mark was 0.25% (1 incident due to a intracranial aneurysm rupture) and at 100-day mark was 0.75% (1 death due to septic shock and 1 due to cardiac failure). Unfortunately, 2 patients succumbed to aggressive myeloma during the same period. Conclusion While we are able to offer HDT to patients with advanced age, cardiac toxicities and renal insufficiency, an explicit conversation regarding known peri-transplant toxicities is necessary to make an informed decision. Very interestingly, 93% of this cohort received risk-adapted maintenance initiating at a median time of 105 days from autotransplants, a surrogate to suggest adequate recovery from transplant related morbidities. Outcomes regarding AA patients and additional progression free and overall survival data by cytogenetic risk will be presented at the meeting.