456P - Oxycodone/naloxone in moderate-to-severe cancer pain: A phase III study in China

Background

As mentioned by ESMO guidelines on the management of constipation in advanced cancer, combined opiate/naloxone medications have been shown to reduce the risk of OIC through a range of studies. Oxycodone/naloxone prolonged-release tablets (OXN PR) provide similar efficacy, but an improved bowel function compared with oxycodone prolonged-release tablets (OXY PR). This is the first Chinese study about OXN PR in cancer pain population.

Methods

This multi-center, randomized, double-blind controlled trial compared OXN PR to OXY PR for 4 weeks in adult cancer patients with moderate-to-severe pain and OIC. Primary efficacy endpoints: Bowel Function Index (BFI) and Brief Pain Inventory-Short Form (BPI-SF). Key secondary endpoints: use of laxative (bisacodyl tablets) and rescue analgesia (morphine sulfate), quality of life (EQ-5D) and safety.

Results

232 patients were randomized (117 in the OXN PR group; 115 in the OXY PR group). BPI-SF average pain was comparable after 4 weeks between OXN PR and OXY PR groups. The difference of average BFI at 4 weeks was not statistically significant between the 2 treatment groups (FAP, p=0.482). Compared to baseline, a BFI reduction was seen after 1 week in OXN PR group (13.5 points vs. 8.8 points in OXY PR group; p=0.039). Results of an exploratory post-hoc analysis confirmed these findings, with the BFI difference favoring OXN PR. Laxative use was similar between the 2 groups, but a higher percentage of patients required laxatives in OXY PR group compared to OXN PR group at all visits. Average daily dose and percentage of patients taking rescue analgesia were similar at 4 weeks. EQ-5D assessment showed a minor improvement in the OXN PR group and a decline in OXY PR group (non-significant). Fewer adverse events were reported in the OXN PR group (17.5% vs. 27.0% in the OXY PR group); No treatment-related SAEs were reported with OXN PR group.

Conclusions

In managing moderate-to-severe cancer pain among Chinese patients, OXN PR has demonstrated comparable efficacy to OXY PR. Improvements of bowel function were numerically observed and statistically confirmed by a post-hoc analysis (p=0.039). This study adds to the wealth of evidence around the positive benefit/risk profile of OXN PR in an Asian population.

Clinical trial identification

NCT00513656.

Editorial acknowledgement

Editorial assistance was provided by MedAcc Technology Co., Ltd.

Legal entity responsible for the study

Mundipharma (China) Pharmaceutical Co.LTD.

Funding

Mundipharma (China) Pharmaceutical Co.LTD.

Disclosure

All authors have declared no conflicts of interest.