The Phase III study "Study 801" of the compound under discussion did have an open-label run-in period, *and* was placebo controlled.
I believe the ct.gov link below is the study under consideration. Regardless, the press release mentions the placebo control.
From the last link:
Zohydro ER was studied in over 1,100 people living with chronic pain who participated in the pivotal Phase 3 efficacy study or an open-label Phase 3 long-term safety study. The efficacy study that enrolled over 500 subjects with chronic low back pain met the primary endpoint in demonstrating that treatment with Zohydro ER resulted in significantly improved chronic pain relief compared to placebo.