Berger, Tamar

Abstract Introduction: Though originating from different cell origins, several reports have described patients with the coexistence of chronic myeloid leukemia (CML) and paraproteinemias, mostly in patients treated with tyrosine kinase inhibitors (TKIs). Objective : To determine whether the prevalence of paraproteinemia in a large cohort of chronic phase (CP-) CML patients is higher than expected in the general population. Methods: We conducted a cross-sectional study among out-patient CP-CML patients treated in a tertiary medical center. Between February 2019 and May 2021 consecutive CP-CML patients who consented to the study, performed the following tests: quantitative immunoglobulin (Ig) levels, serum-free light chains (sFLC), serum protein electrophoresis (SPEP), and if abnormal also serum protein immunofixation (IFIX). The primary outcome was the prevalence of paraproteinemia among this cohort of CML patients. We conducted further analyses to evaluate whether various patient, disease and treatment-related variables are predictors of paraproteinemia within our cohort. Results: One hundred patients, 50% males, with a median age of 63.5 (range 26-91.6) years were recruited for the study. The median time from CML diagnosis to enrollment was 6.3 (range 0.1-23.5) years. Cohort's characteristics are depicted in table 1. Monoclonal (M-) protein was detected on SPEP and IFIX in eight patients (8%), whose median age was 66.8 (range 46-74) years. Among them, two patients had an abnormal sFLC, elevated IgG or IgA levels, on a bone marrow biopsy over 10% monoclonal plasma cells were present, and in the absence of myeloma defining events they were diagnosed with IgG-kappa and IgA-kappa smoldering multiple myeloma (SMM), respectively. The other six patients had normal sFLC ratio and characteristics compatible with low-risk monoclonal gammopathy of undetermined significance (MGUS). Six patients with a detectable M-protein were treated with a TKI [imatinib (n=2), dasatinib (n=3), bosutinib (n=1)] and two were in treatment-free remission (TFR). All continue observation for their paraproteinemia. None of the patients in our cohort was diagnosed with active MM. The presence of anemia was predictive of paraproteinemia, albeit with borderline statistical significance in both univariate (p=0.053) and multivariate analysis (p=0.069). Apart from anemia, no predictors for paraproteinemia were found among various other patient and disease related variables. Conclusions: This is the largest study describing the prevalence of paraproteinemia among CML patients. We found the prevalence of MGUS in CP-CML patients (6%) to be higher than in the general population above the age of 50 (3.2%), and a non-negligible prevalence of SMM (2%). Based on these data, we recommend considering screening for paraproteinemia coexistence in CML patients. Further studies and extended follow-up are needed to elucidate the true clinical significance of our findings. Figure 1 Figure 1. Disclosures Leader: Bayer: Honoraria; Leo Pharma: Honoraria; Novartis: Honoraria; Pfizer: Consultancy, Honoraria; Sanofi: Honoraria.

Introduction Autologous stem cell transplantation (ASCT) has been used for treating multiple myeloma (MM) for over three decades and is generally reserved for patients younger than 65 years of age. The definition of transplant eligible is ill-defined and different centers have different policies to determine which patients are transplant eligible. Some centers have an age cut-off, others use clinical judgment, and some use various frailty scores (a scoring system based on comorbidities and physical and cognitive assessments) aiming to objectively assess transplant eligibility. There are limited data about outcomes in patients ≥ 75 years. Aim To report on outcomes of ASCT in a cohort of patients with MM aged 75 years or older. Methods Retrospective study of all consecutive MM patients aged ≥ 75 years that underwent ASCT at Mayo Clinic, Rochester, Minnesota. Stem cell transplantation at our center is routinely performed as an outpatient, with patients being hospitalized when deemed clinically necessary upon physician review. Results Between October 2005 and March 2020, 46 patients aged 75 years or older, received an ASCT at Mayo Clinic, Rochester. The median hematopoietic stem cell transplantation specific comorbidity index (HCT-CI) was 0 (range 0-6) with 8 patients having HCT-CI of 5 or 6. Median time from diagnosis to ASCT was 6.45 months (IQR 5.2-10.52) and 54% received reduced intensity conditioning with melphalan 140 mg/m2. All patients except one (that was treated with dexamethasone only) received induction with novel agents (listed in table 1) and 6 patients (13%) received doublet induction. All others received triplet induction. 46% of patients completed the ASCT without requiring hospitalization and 54% (n=25) of patients required hospitalization with a median duration of hospital admission of 9 days (IQR 5-13). Reasons for hospitalization included fever or infection (32%), cardiac arrhythmia (36%) and dehydration (32%). Overall response rate was 100% with a complete response seen in 57% of patients and 16 patients achieving MRD negative sCR. Median overall survival and progression free survival for the cohort were 82 months and 33 months, respectively. One patient died within 100 days of transplant representing a 2% 100-day mortality rate. Univariable cox regression model that evaluated the effect of gender, high risk cytogenetics, hemoglobin, renal function and melphalan dose did not detect any variable that was predictive of OS or PFS (Table 3). Conclusions ASCT is efficacious and can be safely delivered in the outpatient setting in carefully screened patients aged 75 or above. An arbitrary cutoff for age should not be used to exclude patients from ASCT, rather a careful assessment of "physiological age" including performance status and co-morbidities is required by an experienced treating team. Disclosures Kumar: Amgen: Consultancy, Other: Research funding for clinical trials to the institution, Consulting/Advisory Board participation with no personal payments, Research Funding; Cellectar: Other; Carsgen: Other, Research Funding; Dr. Reddy's Laboratories: Honoraria; Genentech/Roche: Other: Research funding for clinical trials to the institution, Consulting/Advisory Board participation with no personal payments; Sanofi: Research Funding; Kite Pharma: Consultancy, Research Funding; Novartis: Research Funding; Celgene/BMS: Other: Research funding for clinical trials to the institution, Consulting/Advisory Board participation with no personal payments; Merck: Consultancy, Research Funding; MedImmune: Research Funding; BMS: Consultancy, Research Funding; Tenebio: Other, Research Funding; Karyopharm: Consultancy; AbbVie: Other: Research funding for clinical trials to the institution, Consulting/Advisory Board participation with no personal payments; Janssen Oncology: Other: Research funding for clinical trials to the institution, Consulting/Advisory Board participation with no personal payments; Takeda: Other: Research funding for clinical trials to the institution, Consulting/Advisory Board participation with no personal payments; Genecentrix: Consultancy; Oncopeptides: Consultancy, Other: Independent Review Committee; IRC member; Adaptive Biotechnologies: Consultancy. Dispenzieri:Pfizer: Research Funding; Janssen: Research Funding; Alnylam: Research Funding; Intellia: Research Funding; Takeda: Research Funding; Celgene: Research Funding. Dingli:Bristol Myers Squibb: Research Funding; Rigel: Consultancy; Janssen: Consultancy; Alexion: Consultancy; Karyopharm Therapeutics: Research Funding; Apellis: Consultancy; Sanofi-Genzyme: Consultancy; Millenium: Consultancy. Kapoor:Cellectar: Consultancy; Takeda: Honoraria, Research Funding; Celgene: Honoraria; Amgen: Research Funding; Sanofi: Consultancy, Research Funding; Janssen: Research Funding; GlaxoSmithKline: Research Funding. Gertz:Prothena: Other: personal fee; Medscape: Other: personal fee, Speakers Bureau; Appellis: Other: personal fee; Alnylam: Other: personal fee; Ionis/Akcea: Other: personal fee; Janssen: Other: personal fee; Research to Practice: Other; Sanofi: Other; Teva: Speakers Bureau; Johnson and Johnson: Speakers Bureau; DAVA oncology: Speakers Bureau; Proclara: Other; Springer Publishing: Patents & Royalties; Celgene: Other; Physicians Education Resource: Other: personal fee; Aurora Bio: Other; Amgen: Other: personal fee; Annexon: Other: personal fee; Spectrum: Other: personal fee, Research Funding; Abbvie: Other.