Background: APOLLO (NCT03180736) is a phase 3 trial of pomalidomide and dexamethasone (Pd) ± subcutaneous daratumumab (1800 mg, co-formulated with recombinant human hyaluronidase PH20 in 15 mL) in patients with RRMM and ≥1 prior line of therapy including lenalidomide and a proteasome inhibitor. After 16.9 months (mo) median follow-up, D-Pd significantly reduced the rate of progression or death by 37% relative to Pd. Patients with RRMM have reduced HRQoL compared with age- and sex-matched populations. Here, we present PROs from the APOLLO trial. Methods: Patients were randomized 1:1 to D-Pd or Pd and treated in 28-day cycles until disease progression/unacceptable toxicity. PROs were assessed on Day 1 of each cycle using the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire Core 30-item (EORTC QLQ-C30), EORTC QLQ Multiple Myeloma Module 20-item (MY20), and EuroQol 5-dimensional descriptive system. PRO analyses were performed on patients from the intent-to-treat population with a baseline (BL) and ≥1 post-BL assessment. Treatment effect was assessed by a mixed effects model with repeated measures. Time to worsening was estimated using the Kaplan-Meier method. Results: A total of 304 patients were included (151 D-Pd, 153 Pd). Median treatment duration was 11.5 mo with D-Pd vs 6.6 mo with Pd. At Cycle 16 (Cyc 16), 63 and 40 patients remained on treatment in the D-Pd and Pd groups, respectively. Compliance rates for PRO instruments were high and comparable between groups. Patients treated with D-Pd had a reduction in pain (maximum improvement: 6.8 points at Cyc 12) measured with the EORTC QLQ-C30 and no mean change in disease symptoms or the treatment side effects subscales of the EORTC QLQ-MY20. Group mean physical and emotional functioning were unchanged from BL with D-Pd but worsened in the Pd group (maximum worsening: 6.4 at Cyc 4 and 9.1 points at Cyc 14). The proportion of patients with a meaningful improvement from BL was 55.0% vs 49.0% for disease symptoms, 43.0% vs 35.3% for physical functioning, and 41.7% vs 31.4% for emotional functioning with D-Pd vs Pd, respectively. Median time to worsening was ̃4 mo, except for the disease symptoms subscale (̃10 mo); there were no differences between groups. Conclusions: When daratumumab was added to Pd, patients did not experience any decrements in HRQoL while on treatment, but some patients experienced reductions in pain as well as clinically meaningful improvements in symptoms and emotional/physical function. These findings complement the clinical benefits of D-Pd in RRMM patients and further support its use in this RRMM population. Clinical trial information: NCT03180736