Real-world analysis of thromboembolism in SAVED/IMPEDE risk-stratified newly diagnosed multiple myeloma (NDMM).

7561 Background: The rate of thromboembolic (TE) events in NDMM patients (pts) treated with IMiD-containing regimens ranges from 11-19%, with venous events (VTE) being more common than arterial events (ATE). The SAVED and IMPEDE scores have been developed to risk-stratify thrombotic risk in NDMM. However, data on risk of VTE based on SAVED and IMPEDE VTE scores is largely unavailable for adequate contextual understanding of the problem. Methods: We queried the electronic medical record at Vanderbilt University Medical Center for pts with NDMM treated between January 2017 and May 2022, with a follow up for ≥ 2 years or until death. Information on incidence of TE, SAVED and IMPEDE scores at diagnosis, and the type of thromboprophylaxis (ppx) [any dose anticoagulation (AC) vs any dose aspirin (ASA) vs no ppx] present at induction therapy was analyzed. Pts were categorized as having elevated VTE risk if they had either SAVED ≥ 2 or IMPEDE ≥ 4 (patients with ATE were excluded). VTE rates were compared by χ 2 tests, and time to event was compared by Wilcoxon rank-sum test. Results: Among 178 pts with NDMM, the median (range) age was 65 (39-88) years. Upfront transplant was done in 76 (42.7%) of pts and IMiD containing therapy was used in 113 (63.5%) pts. The median (range) SAVED score was 1 (-2 to 7), and the median IMPEDE score was 2 (-3 to 12). Overall, 39 pts (21.9%) were diagnosed with TE [35 (19.7%) VTE, 4 (2.2%) with ATE]. Median (range) time to VTE was 7.7 months (mo) (0-42.3). Overall, 132 (74.1%) pts were on ASA, 26 (14.6%) were on AC, and 20 (11.2%) on no ppx. Among VTE pts, 25 (71.4%) were on ASA, 5 (14.3%) were on AC, and 5 (14.3%) on no ppx. Among VTE pts vs those without an event, a total of 20 (57.1%) vs 67 (48.2%) (p = 0.3) pts were categorized as having elevated risk, respectively. Among all pts with elevated VTE risk (n=84) vs not (n=90): VTE incidence was 23.8% (n=20) vs 16.7% (n=15) (p=0.24), and median (range) time to VTE was 5.5 (0-24.1) mos vs 9.1 (0-42.3) mos (p=0.12). Among those with elevated VTE risk, 18 (21.4%) received AC, 53 (63.1%) received ASA, and 13 (15.5%) were on no ppx. Among pts with elevated risk on AC versus ASA, VTE incidence was 11% (n=2) vs 26.9% (n=14) (p=0.3). Lastly, VTE rate was 19.1% (deep vein thrombosis (DVT) 12.2%, pulmonary embolism (PE) 6.9%), 19.2% (15.4% DVT, 3.8% PE), and 30% (10% DVT, 20% PE) among all pts on ASA, AC, and no ppx, respectively. Conclusions: Despite most patients harboring low predicted VTE risk at diagnosis by SAVED/IMPEDE, VTE rate was unacceptably high, and primarily occurred beyond 6 mos in our real-world NDMM cohort. Furthermore, VTE risk was not adequately mitigated in this ASA-ppx-enriched cohort. Though limited by small sample size, VTE events were numerically higher and had faster onset among patients with elevated SAVED/IMPEDE risk compared to those with low risk, while AC ppx in elevated-risk pts showed a trend towards reduced VTE incidence compared to ASA.