New data from two trials of Zubsolv for Opioid Dependence-Orexo

Orexo has announced the results of two clinical trials assessing Zubsolv (buprenorphine and naloxone) for induction of buprenorphine maintenance therapy in patients with Opioid Dependence. Combined data from the ISTART (Study OX219-006) and Study OX219-007, in 1068 patients showed that over 90% of patients treated with Zubsolv were retained in treatment at Day 3 using a 30% lower dose of buprenorphine. The two studies had similar structure during the three-day induction phase to enable a combined analysis of the induction results, with the ISTART being the most important contributing with 70% of the patients.

An analysis of the combined data from the ISTART and OX219-007 studies found no difference when comparing Zubsolv and generic buprenorphine monotherapy when used as treatment for the induction of buprenorphine maintenance therapy. In the combined per protocol set, 92.3% (422/457) of patients in the Zubsolv group were retained in treatment at Day 3 compared to 93.4% (424/454) of patients receiving generic buprenorphine. Similar results were observed in the combined full analysis set where 90.9% (489/538) of patients in the Zubsolv group were retained at Day 3 compared to 92.6% (491/530) generic buprenorphine group. These results enable Orexo to pursue a regulatory submission of an expanded label of Zubsolv to include initiation of treatment in the US.