Adoption of triplet therapy and clinical outcomes in routine practice among newly diagnosed multiple myeloma patients not receiving frontline stem cell transplant in the USA

Triplets with immunomodulators (IMIDs) and proteasome inhibitors (PIs) improve overall survival (OS) in trials of newly diagnosed multiple myeloma (NDMM) patients although reported outcomes in routine practice are lacking. Authors compared outcomes in NDMM patients in the USA by use of triplet vs doublet frontline therapy (FT). 

This is a retrospective electronic health record database study of NDMM patients without transplant in FT between 1/1/2008 and 6/30/2017. FT was categorized as: PI+IMID-triplet (≥3 drugs including PI+IMID), non-PI+IMID-triplet (≥3 drugs, not PI+IMID), doublet (≤2 drugs). Univariate and multivariate analyses identified FT triplet use predictors and compared time-to-next-treatment (TTNT)/OS from FT initiation. 

Among 4,982 NDMM patients, 68% and 32% initiated doublet and triplet FTs (PI+IMID: 36% in 2017). Younger age, high-risk cytogenetics, ISS stage III, anemia, hypercalcemia, and bone disease were associated with increased odds of triplet FT. Median TTNTPI+IMID-triplet=18.9 months vs 13.7 (non-PI+IMID-triplet) and 16.5 months (doublet) FTs (P<0.01); adjusted HRPI+IMID-triplet=0.86; P=0.009; HRnon-PI+IMID-triplet=1.10; P=0.083 vs doublet FT. Median OSPI+IMID-triplet=58.7 months vs 43.6 (non-PI+IMID-triplet) and 45.7 months (doublet) FTs (P<0.01); adjusted HRPI+IMID-triplet=0.83; P=0.016; HRnon-PI+IMID-triplet=1.02; P=0.727 vs doublet FT. 

The majority of non-frontline-transplant NDMM patients do not receive PI+IMID-triplet FTs in routine care, which was associated with prolonged TTNT/OS.