P-167: Real-world elderly myeloma patients: improved survival despite more adverse risk factors than younger patients and RCT populations. A study on behalf of the Nordic Myeloma Study Group

Abstract

<h3>Background</h3> Elderly multiple myeloma (MM) patients are underrepresented in randomized clinical trials (RCTs). Prospective registries provide insight into real-world patient characteristics, treatment and outcome. The Danish Multiple Myeloma Registry (DMMR) and the Swedish Myeloma Registry (SMR), established in 2005 and 2008 respectively, are nationwide prospective registries with near 100% coverage. <h3>Methods</h3> We describe baseline characteristics, treatment and survival for patients diagnosed with active myeloma in the DMMR January 1st 2005-February 18th 2020, and the SMR January 1st 2008-December 31st 2019. We performed a retrospective comparison of patients aged ≥75 years at diagnosis to MM patients <75 years. Further, we compared our cohort to the populations in pivotal RCTs guiding the treatment of elderly myeloma patients. <h3>Results</h3> In total, we report on 4647 Swedish and Danish MM patients ≥75 years at diagnosis compared with MM patients <75 years (n=7378). Out of 4691 newly diagnosed MM patients in the DMMR, 36% (n=1688) were ≥75 years. Among 7334 MM patients in the SMR, 40% (n=2959) were ≥75 years. The elderly cohort presented with more advanced disease (46% ISS III in both registries vs 30.3% (SMR) and 34.6% (DMMR) among the younger cohorts). The proportion of patients with anemia and/or renal failure was higher in the older cohort. In comparison, important RCTs underpinning current treatment guidelines included a lower proportion of elderly patients and patients with ISS III. 30% of patients in the VISTA-trial (VMP vs MP) and the ALCYONE-trial (Dara-VMP vs VMP) were ≥75 years. In the FIRST trial (Rd continuously vs Rd 18 months vs MPT) 35% of patients were >75 years, while the MAIA trial (Dara-Rd vs Rd) has the largest proportion of elderly patients among these studies (43.6%). However, in the MAIA trial only 29% of patients presented with ISS III, compared to 46% of patients ≥75 years in our real-world population. Similarly, 35% of patients in VISTA and 38% in ALCYONE had ISS III. The FIRST trial had a composition more similar to the Swedish and Danish registry population with 35% of patients >75 years, and 48% of these patients with ISS stage III. The treatment strategies in the elderly were similar in Denmark and Sweden. Melphalan and prednisolone (MP) were replaced by bortezomib-based regimes from around 2012, while lenalidomide-based treatment increased in recent years. Median relative survival (RS) for patients ≥75 years in Denmark increased from 25 months to 36 months for patients diagnosed 2005-2007 and 2015-2016, respectively. Similarly, in Sweden the median RS increased from 24 months to 42 months for patients ≥75 years diagnosed 2008-2009 and 2016-2017, respectively. <h3>Conclusion</h3> The real-world MM population is older and has a higher proportion of patients with ISS III disease than patients included in the pivotal RCTs, and compared to the younger patient cohort. Future studies in MM patients should take this into account.