Candidate germline biomarkers of lenalidomide efficacy in mantle cell lymphoma: the FIL MCL0208 trial

In the FIL MCL0208 phase III trial, lenalidomide maintenance (LEN) after transplantation (ASCT) in mantle cell lymphoma (MCL) improved progression-free survival (PFS) vs observation (OBS). The host pharmacogenetic background was analyzed to decipher whether single nucleotide polymorphisms (SNPs) of genes encoding transmembrane transporters, metabolic enzymes, or cell surface receptors might predict drug efficacy. Genotypes were obtained by real-time polymerase chain reaction (RT-PCR) in peripheral blood (PB) germ line DNA. Polymorphisms of either ABCB1 or VEGF were found in 69% and 79% of 278 patients and predicted favorable PFS vs homozygous wild type (WT) in the LEN arm: 3-year PFS 85% vs 70% (p < 0.05) and 85% vs 60% (p < 0.01), respectively. Patients carrying both ABCB1 and VEGF WT had the poorest 3-year PFS (46%) and overall survival (OS, 76%): in fact, in these patients LEN did not improve PFS vs OBS (3-year PFS 44% vs 60%, p = 0.62). Moreover, CRBN polymorphism (n = 28) was associated with lenalidomide dose reduction or discontinuation. Finally, ABCB1, NCF4, and GSTP1 polymorphisms predicted lower hematological toxicity during induction, while ABCB1 and CRBN polymorphisms predicted lower risk of grade ≥3 infections. This study demonstrates that specific SNPs represent candidate predictive biomarkers of immunochemotherapy toxicity and LEN efficacy after ASCT in MCL. This trial is registered at eudract.ema.europa.eu as 2009-012807-25.