Pain Therapeutics, Inc. (NASDAQ:PTIE) is looking at an eventful upcoming stretch concerning Remoxy, its late-stage drug candidate. This morning, the drug maker announced positive results from a human abuse potential study of REMOXY, sending shares skyrocketing nearly 150%.
As a result, the company plans to resubmit the REMOXY NDA to the FDA shortly. Study results indicate that in non-dependent, recreational opioid users, nasal administration of REMOXY resulted in significantly lower abuse potential compared to immediate-release (IR) oxycodone. All study subjects reported reduced ‘Drug Liking’ ‘Take Drug Again’ and ‘Drug High’ for REMOXY compared to oxycodone IR. In addition, nasal administration of REMOXY showed lower exposure to oxycodone, lower peak concentrations (Cmax) and longer time to peak drug concentration (Tmax) against comparator drugs, suggesting comparatively lower abuse potential.
Design & Methods:
This Category 3 nasal abuse potential study was conducted in accordance with the U.S. Food and Drug Administration’s (FDA) Guidance for Industry for Abuse-Deterrent Opioids. In a randomized, double-blind, active- and placebo-controlled, single-dose, 4-way crossover study, 38 recreational opioid users with a history of intranasal drug abuse were enrolled in the study. The primary endpoint was ‘Drug Liking’. Secondary endpoints included ‘Take Drug Again’, ‘Drug High’ and pupil size. There were four treatment arms: REMOXY 40 mg intact; REMOXY 40 mg microwaved; oxycodone IR 40 mg; and placebo. All treatments were administered nasally. Thirty-six subjects completed the study. In addition, the first 20 subjects who completed the double-blind portion of the study also participated in a supplemental FDA Category 2 treatment arm to measure pharmacokinetic parameters following the nasal administration of 40 mg crushed OxyContin®.
Top-Line Study Results:
REMOXY intact and microwaved each demonstrated lower VAS scores on the primary endpoint, Drug Liking (p<0.01) versus oxycodone IR, indicating that oxycodone IR was significantly preferred over REMOXY.
On secondary endpoints, REMOXY intact and microwaved each demonstrated lower scores versus oxycodone IR on Take Drug Again, Drug High and pupil size (each p<0.001 or better).
On all pharmacokinetic parameters, REMOXY resulted in significantly lower exposure to oxycodone compared to oxycodone IR and crushed OxyContin. Peak oxycodone concentrations (Cmax) were at least 4-fold lower for REMOXY, microwaved or intact, compared to crushed OxyContin or oxycodone IR. Additionally, time to reach peak oxycodone concentrations was 3.5 times as long for REMOXY compared to crushed OxyContin. The Cmax values for nasally administered REMOXY, microwaved REMOXY, crushed OxyContin and oxycodone IR were 14.9, 11.9, 63.6 and 64.7 ng/ml, respectively. Tmax values were 3.1, 3.1, 0.88 and 1.6 hours, respectively.
Finally, the Abuse Quotient (AQ=Cmax/Tmax) is an essential measurement of abuse potential, with lower scores suggesting comparatively lower potential for abuse.
In this study, AQ measurements were: <5.0 for REMOXY, intact or microwaved 72.3 for OxyContin crushed 40.4 for oxycodone IR
Pain Therapeutics is a biopharmaceutical company, which engages in the development of novel drugs. Its drug candidate includes REMOXY, which is a strong painkiller with a unique formulation designed to reduce potential risks of unintended use.