3 - Diversion and street price of XTAMPZA® ER relative to other prescription opioids

¹Rocky Mountain Poison & Drug Safety – Denver Health and Hospital Authority, Denver, CO, USA. ²University of Colorado School of Medicine, Aurora, CO, USA

Purpose
Prescription opioids are a common treatment for chronic and severe pain; however, these medications have a well-documented risk of abuse. Many individuals who abuse prescription opioids obtain these medications after they are diverted from legal distribution channels. The frequency with which a particular product is diverted and the price paid in illegal markets may be indicators of the demand among individuals who abuse opioids. Both measures have been shown to be sensitive to targeted interventions intended to reduce non-medical prescription opioid abuse. XTAMPZA^® ER is an abuse deterrent extended-release (ER) oxycodone product that uses DETERx^® technology designed to discourage product manipulation for misuse and abuse by oral and non-oral routes. This study assesses the extent of diversion and average street price paid for XTAMPZA ER relative to other prescription opioid analgesics.
Methods
Researched Abuse, Diversion and Addiction-Related Surveillance (RADARS^®) System Drug Diversion Program and StreetRx Program from 2018 and 2019 were used. The Drug Diversion Program obtains information on new cases of diversion reported by law enforcement and regulatory agencies in 49 states. The StreetRx Program collects black market drug price information via anonymous submissions to the StreetRx.com website. In both programs, XTAMPZA ER was compared to two groups: other abuse deterrent formulation (ADF) ER opioids, and immediate-release (IR) oxycodone. ADF ER opioids included OxyContin^®, Embeda^®, Hysingla^® ER, Arymo^® ER, and MorphaBond™ ER. With Drug Diversion Program data, rates of diversion cases were calculated per prescriptions dispensed and morphine equivalent grams dispensed and compared. Both estimates were obtained from the IQVIA^® (Danbury, CT) US-Based Longitudinal Patient Data. In the StreetRx Program, the geometric mean price per milligram strength was compared between drug groups. Unadjusted geometric mean street price and geometric mean street price adjusted for tablet strength and active pharmaceutical ingredient were assessed.
Results
From 2018 through 2019, there were 737,565 (increasing by quarter) prescriptions for XTAMPZA ER, 4.8 million (decreasing by quarter) for other ADF ER opioids, and 79 million (decreasing by quarter) for IR oxycodone. There were 2,416 cases of diversion involving drug groups of interest captured in the Drug Diversion Program; 5 involved XTAMPZA ER, 128 involved other ADF ER opioids, and 2,083 involved IR oxycodone. The diversion rates per prescriptions dispensed were all statistically significantly greater for comparator drug groups relative to XTAMPZA ER. Relative to XTAMPZA ER, the IR oxycodone diversion rate was 3.7 (95% CI: 1.5-8.8, p=0.004) times greater and the other ADF ER opioids diversion rate was 3.8 (95% CI: 1.5-9.2, p=0.004) times greater. Adjusting for morphine equivalent grams dispensed, the IR oxycodone diversion was 5.9 (95% CI: 2.5-14.3, p<0.001) times greater and the other ADF ER opioids diversion rate 2.8 (95% CI: 1.1-6.9, p=0.024) times greater.
The unadjusted geometric mean price of IR oxycodone was highest ($1.04 per mg, 95% CI: $1.00-1.07), followed by XTAMPZA ER ($0.59, 95% CI: $0.50-0.69), and other ADF ER Opioids ($0.50, 95% CI: $0.46-0.53). After adjusting for tablet strength and active pharmaceutical ingredient, XTAMPZA ER had the lowest estimated price per milligram but differences with comparator drug groups were not statistically significant.
Conclusions
Diversion of XTAMPZA ER was observed though it comprised a smaller number of cases than would be expected based on prescription volume and drug potency. The appropriate comparator based on FDA guidelines is IR oxycodone. IR oxycodone had the highest number of cases. Using two different drug availability measures (prescriptions dispensed and morphine equivalent grams dispensed), diversion of IR oxycodone and other ADF ER opioids was significantly higher than XTAMPZA ER. The street price of XTAMPZA ER is lower than IR oxycodone products among individuals who abuse opioids. No differences in price per milligram were observed between XTAMPZA ER and comparator drug groups after adjusting for differences in tablet strength and active pharmaceutical ingredient. These data sources do have limitations. The Drug Diversion Program is not a representative sample and may be affected by regional differences in law enforcement efforts. Data in StreetRx are self-reported and subjective to recall and recognition biases. Though diversion of XTAMPZA ER is rare, continued monitoring is warranted to identify sources and reasons for illegal acquisition.