The goal of this study was to compare topical dexamethasone 1.5% in a novel formulation (OCS-01) once daily and BID versus vehicle for the treatment of inflammation and pain after cataract surgery. This was a Phase II, double-masked, vehicle-controlled, randomized multicenter study. Adult patients with planned unilateral uncomplicated cataract surgery were randomized to receive OCS-01 once daily (n=51), OCS-01 BID (n=51), or matching vehicle (n=51) for 15 days postsurgery. Primary end points were absence of anterior chamber cells (ACC; cells=0) at Day 15 and absence of pain (score of "0") at postoperative Day 4. The Pearson χ2 test with a two-sided alpha=0.1 was used to compare treatments. Safety was assessed in terms of adverse events and changes in intraocular pressure. Treatment arms were generally similar in their baseline characteristics, with mean age ranging from 66 to 68 years, the proportion of male patients ranging from 29% to 37%, and 82% to 92% of each arm being White. On Day 15, a greater reduction in the percentage of eyes with ACC grade 0 was observed in the OCS-01 once daily (51%) and BID (66.7%) arms than in the vehicle arm (19.6%) (P=0.0009 and P < 0.0001, respectively, using a Pearson χ2 test). On Day 4, the percentage of eyes with no pain was 72.5% (OCS-01 once daily), 62.7% (OCS-01 BID), and 45.1% (vehicle); statistical significance was reached for OCS-01 once daily (P=0.005) and OCS-01 BID (P=0.074) compared with vehicle. OCS-01 was well tolerated. A higher proportion of treatment-emergent adverse events, including ocular adverse events, were reported for the placebo group than for either OCS-01 group. OCS-01 once daily and BID were more effective than vehicle and well tolerated in the treatment of inflammation and pain after cataract surgery. gov identifier: NCT04130802.