PB2341 OUTCOMES OF PATIENTS WITH MULTIPLE MYELOMA FOLLOWING AUTOLOGOUS STEM CELL TRANSPLANT ACCORDING TO POST‐TRANSPLANT TIME OF RESPONSE: A SINGLE CENTER EXPERIENCE OF 148 CONSECUTIVE TRANSPLANTS
Authors: S. Saadeh, M. Ma’koseh, M. Al‐Essa, H. Abu‐Jazar, K. Halahleh, W. Daana, R. Al‐Far
Journal: HemaSphere (2019)

Background: Even in an era where there is rapid development and approval of novel agents for the management of multiple myeloma, autologous stem cell transplant remains an attractive, effective line of therapy, and is still considered the standard of care in many institutions. Although post‐transplant maintenance is considered standard of care at many institutions, it is not approved or covered by insurance in Jordan due to cost. Instead, tandem transplant is used in high risk patient and for those with less than adequate response to their first transplant. The decision to proceed to the second of a tandem transplant is based on both initial disease risk stratification, to degree of response at disease evaluation on or near day 100 (D100) post‐transplant. Whether patients who to achieve further response beyond D100 do as well as patient who achieve CR at D100 and so can forgo a second transplant is unknown Aims: We aim to report on outcomes of patients diagnosed with multiple myeloma following autologous stem cell transplant according to time of response defined as complete remission (CR) at D100, versus further response and CR beyond D100, versus never achieving CR following first stem cell transplant Methods: We retrospectively analyzed records of all adult autologous transplants performed from January 2008 to Dec 2017. Data was collected only for patients who underwent a single transplant. Descriptive statistics and multivariable logistic regression were used to characterize the cohort and determine predictors of response. Kaplan‐Meier plots were used to estimate PFS and OS Results: A total of 148 patients were identified. Median age at diagnosis was 52 years and 60.1% of patients were males, with a median follow‐up of 42.4 months. At time of initial diagnosis, 30% of patients had advanced stage disease, median time form diagnosis to transplant was 13.8 months, and 28.4% of patients received more than 1 line of therapy before transplant. Median PFS and OS for the entire group of patients was 29.1 and 92.7 months, respectively. Complete remission at D100 was achieved in 52.7% (n = 78) of patients (group 1), while 8.8% (n = 13) achieved CR beyond D100 (group 2) without further therapy, and 38.5% (n = 57) never achieved CR (group 3). Median OS for the 3 groups was 92.7, not reached, and 52.2 months, respectively (Figure 1). Although there is a clear separation of curves, this was not statistically significant. Median PFS for the 3 groups was statistically significant; 35.3, 47.1, and 16.4 months, respectively (p = 0.001, Figure 2). Patients who achieved CR beyond D100 seem to do better than those with CR at D100, but this might be a bias due to the small number of patients (n = 13 for group 2). Within each group, neither PFS nor OS were affected by age at time of transplant, number of cycles before transplant, time form diagnosis to transplant (&lt;12 months vs ≥12 months), or stage of disease at initial diagnosis Summary/Conclusion: Patients who achieve CR following autologous stem cell transplant do better then patients who do not, regardless of time of CR (D100 or beyond). The risk stratification and choice of further post‐transplant therapy, such as decision to proceed to a second transplant can probably be delayed image