Background: Upfront LEN until disease progression is a standard treatment (Tx) in multiple myeloma (MM). Data are limited on optimal Tx after first-line LEN, especially in LEN-refractory patients (pts), a growing population. In OPTIMISMM (phase 3, NCT01734928), PVd significantly improved median PFS at first relapse in relapsed refractory MM (RRMM) pts, of whom 100% were LEN pretreated and 57% were LEN refractory (median, 20.7 vs 11.6 mos; HR = 0.54 [95% CI, 0.36-0.82]; P = .0027) vs Vd (Richardson, 2019). Pd has shown efficacy and safety in RRMM pts with moderate or severe renal impairment (RI), including those on dialysis (Dimopoulos, 2018). However, outcomes with second-line PVd in RRMM pts with RI have not been assessed. Here we report efficacy and safety of PVd vs Vd at first relapse by renal status (CrCl < 60 vs ≥ 60 mL/min). Methods: Pts received PVd or Vd (1:1) in 21-day (D) cycles (C); POM 4 mg/D on D1-14 (PVd arm only); BORT 1.3 mg/m² on D1, 4, 8, 11 of C1-8 and on D1, 8 of C9+; and DEX 20 mg/D (10 mg/D for pts aged > 75 yrs) on days of and after BORT. Pts on dialysis were excluded. Results: Of 559 pts enrolled, 226 (40%) had 1 prior line of therapy; of whom 28% had CrCl < 60 mL/min and 4% had severe RI (CrCl < 30 mL/min). In pts with CrCl < 60 mL/min (PVd vs Vd), median age was 74 vs 73 yrs. In pts with CrCl ≥ 60 mL/min (PVd vs Vd), median age was 62 vs 64 yrs. A higher proportion of pts with baseline CrCl < 60 (23% vs 43%) than ≥ 60 mL/min (7% vs 8%) had ISS stage III at study entry. Data cutoff was Oct 26, 2017. Median PFS was improved with PVd in both renal groups (Table). ORR significantly improved regardless of renal status. Depth of response also improved with PVd vs Vd; ≥ VGPR occurred in 54% vs 21% in the CrCl < 60 mL/min group and 64% vs 23% in the CrCl ≥ 60 mL/min group. Myelosuppression was the most common grade 3/4 TEAE (Table). Conclusions: Second-line PVd led to improved vs Vd in pts with RRMM and RI; however, the PFS difference was not statistically significant. Safety was consistent for PVd with no new signals in pts with RI. These findings further support the earlier use of POM-based Tx in RRMM pts, including those with mild to moderate RI. Clinical trial information: NCT01734928