Table 1.

Challenges of conducting clinical trials to prevent or treat disease relapse after allo-HCT

Agent specific

Off-target toxicities including cytopenias/additional immunosuppression

Induction of GVHD

Impairment of effective graft-vs-malignancy effect

Drug-drug interactions

Disease specific

No singular target for the majority of diseases

No validated reliable MRD assays for majority of diseases to act preemptively

Competition with other trials/modalities

Population specific

Competing risk of opportunistic infection

Competing risk of GVHD

Trials conducted will have inherent selection bias given early dropout after allo-HCT

Industry specific

Reluctance to conduct early-phase trials in the post–allo-HCT setting

Access to agents inhibits enrollment in randomized trials

Small market