Three studies involving a total of 627 patients with opioid dependence showed that Sixmo is effective at reducing patients’ intake of opioids.

The first study compared Sixmo with placebo (dummy) implants in 163 patients who had not received buprenorphine before. During the first 4 months of treatment, the percentage of negative urine tests for opioids was around 40% for patients treated with Sixmo, compared with around 28% for those treated with placebo.

The second study in 287 patients who had not received buprenorphine before compared Sixmo with placebo implants and with sublingual buprenorphine (given under the tongue). During the 6 months of treatment, the percentage of negative urine tests for opioids was around 31% for Sixmo, 13% for placebo and 33% for sublingual buprenorphine.

In both of these studies, the number of urine tests that were negative for opioid use decreased towards the end of the treatment period, indicating a reduction of the effect of Sixmo over time.

The third study compared Sixmo with sublingual buprenorphine in 177 patients whose opioid dependence was already being managed with sublingual buprenorphine at a daily dose of up to 8 mg. After 6 months of treatment, around 96% of patients who received Sixmo responded to treatment (i.e. there was no evidence of opioid use in at least 4 out of 6 months) compared with around 88% in patients on sublingual buprenorphine.