The 4-year overall survival (OS) rate is 82.3% among patients diagnosed with multiple myeloma at age 65 years or younger, who are eligible for autologous stem cell transplantation (ASCT), according to a retrospective single-institution study at the Mayo Clinic (abstract 3138). The findings were reported at a poster presentation at the 59th American Society of Hematology (ASH) Annual Meeting and Exposition, held December 9–12 in Atlanta.
The study bolsters the case that a similar recent estimate based on a clinical trial population reflects real-world clinical experience.
“This is a benchmark for this patient population; benchmark 4-year OS rates for standard and high-risk multiple myeloma are 86.3% and 68.2%, respectively,” reported lead study author Ashley Paquin, BA, of the Mayo Clinic School of Medicine, and coauthors from the division of hematology at the Mayo Clinic, in Rochester, Minnesota.
A comparative-effectiveness analysis also demonstrated nearly identical 4-year OS rates in standard-risk patients undergoing different common contemporary antimyeloma induction regimens (83% to 88%).
The OS time for multiple myeloma has improved in recent years, with a recently reported 4-year OS rate of 82% among patients receiving lenalidomide, bortezomib, and dexamethasone alone or with ASCT.
But such optimistic OS estimates are based on outcomes from the highly selected population of patients who enroll in clinical trials, and these might not represent real-world outcomes, the researchers noted.
To estimate clinical outcomes for a more generally representative multiple myeloma patient population, the researchers conducted a review of all patients younger than age 65 at the time of diagnosis with myeloma, who were eligible for ASCT from 2010 to 2015 and from whom stem cells were harvested within 12 months of diagnosis. (Data for patients with a baseline serum creatinine level of > 2 gm/dL were excluded from analysis.)
They analyzed the 4-year OS rates and conducted a comparative-effectiveness analysis for the lenalidomide, bortezomib, and dexamethasone regimen and other induction regimens used during the study period at Mayo Clinic. Patients were stratified by chromosomal risk factors.
Among 369 standard-risk patients, the 4-year OS rates were 85% among patients undergoing induction with an immunomodulatory drug (IMiD) and a proteasome inhibitor (PI), 83% in patients receiving PI/alkylator regimens, and 88% in patients receiving doublet induction therapy. Among 113 high-risk patients, 4-year OS rates were 88% for a PI/alkylator regimen, compared with 69.5% for IMiD/PI therapy and 67% for doublet induction therapy.
The researchers plan to further stratify patient survival by cytogenetic risk markers and treatment regimens in a subsequent analysis.