Minimal Residual Disease as a Potential Surrogate End Point—Lingering Questions

In the treatment of multiple myeloma (MM), there have been important advances in recent decades. The introduction of new therapeutics, the use of high-dose therapy, and better supportive care have translated into longer progression-free survival (PFS), overall survival (OS) times, and higher response rates.¹ For example, in a recent phase 3 randomized trial² evaluating lenalidomide and dexamethasone with or without daratumumab, the reported overall response rate was 93%. Given these improvements, there has been interest in the development of surrogate end points to expedite drug development.