AZD2066 Neuropathic Pain - Mechanical Hypersensitivity

• AZD2066 (Drug): Capsule, once daily
• Placebo (Drug): Capsule, once daily

Primary outcomes

• Change in Mean Numerical Rating Scale (NRS) Pain Score From Baseline to Last 5 Days on Treatment [Change in mean pain intensity from 5-day baseline to the last 5 days on treatment, measure twice daily with NRS (12-hour recall)]: Mean pain intensity for 5-day baseline period (morning Day -5 to evening Day-1) and mean pain intensity for last 5 days on treatment (ie, last dose day and the 4 preceding calendar days) was calculated based on the NRS scale (0-10). 0=No pain, 10=Worst pain imaginable.

Secondary outcomes

• Patients With ≥30% Reduction From Baseline in NRS Pain Intensity Score (Responder Rate) at Day 28 [28 days]: NRS pain intensity score reduction=(change from baseline at Day 28/baseline)*100 Responder=pain intensity score reduction ≥30% (yes/no)? Responder rate=(no. of responders/total no. of patients)*100
• Patients With ≥50% Reduction From Baseline in NRS Pain Intensity Score (Responder Rate) at Day 28 [28 days]: Pain intensity score reduction=(change from baseline Day 28/baseline)*100 Responder=pain intensity score reduction ≥50% (Yes/No)? Responder rate=(no. of responders/total no. of patients)*100
• Patients With Patient Global Impression of Change (PGIC) Score of at Least "Much Improved" (Responder Rate) at Day 28 [28 days]: PGIC scale ranges from 1-7 where 1=Very much improved and 7=Very much worse Responder=Patient with a response of " much improved" or "very much improved" Responder rate=(no. of responders/total no. of patients)*100
• Change in Short Form McGill Pain Questionnaire (SF-MPQ) Sensory Index From Baseline to Day 28 [28 days]: Sensory index=sum of the intensity scale values of the words chosen for the descriptors 1-11 in the questionnaire. Range of scores for the sensory index=0-33 (higher score represents a worse condition). Change from baseline (measured prior to randomization) to Day 28 was calculated.
• Change in SF-MPQ Affective Index From Baseline to Day 28 [28 days]: Affective index=sum of the intensity scale values of the words chosen for the descriptors 12-15 in the questionnaire. Range of scores for the affective index=0-12 (higher score represents a worse condition). Change from baseline (measured prior to randomization) to Day 28 was calculated.
• Change in Brief Pain Inventory-Short Form (BPI-SF) Pain Severity From Baseline to Day 28 [28 days]: Change from baseline (measured prior to randomization) to Day 28 was calculated for the pain severity (mean of 4 intensity items). Each intensity item is recorded on a NRS 0-10, where 0=No Pain and 10=Pain as bad as you can imagine.
• Change in BPI-SF Pain Interference From Baseline to Day 28 [28 days]: Change from baseline (measured prior to randomization) to Day 28 was calculated for pain interference (mean of 7 interference items). Each interference item is recorded on a NRS 0-10, where 0=No interference and 10=Interferes completely.

Sex: All, ages: 18 Years to 80 Years

Inclusion Criteria:

* Provision of informed consent prior to any study specific procedures.
* Male or non-fertile females
* Painful symptoms due to neuropathic pain for a period of 3 months to 5 years, associated with mechanical allodynia and/or punctate hyperalgesia.

Exclusion Criteria:

* Other pain that may confound assessment of neuropathic pain.
* Diagnosis of any severe neurological disease.
* History of significant psychiatric disease/condition and/or history of psychotic disorders among first degree relatives.

Participant flow

Outcome results

• Change in Mean Numerical Rating Scale (NRS) Pain Score From Baseline to Last 5 Days on Treatment (Primary), Least squares mean, Scores (units) on NRS: A - AZD2066 -2.14 +/- 0.358; 2 - Placebo -1.26 +/- 0.337
• Patients With ≥30% Reduction From Baseline in NRS Pain Intensity Score (Responder Rate) at Day 28 (Secondary), Number, Participants: A - AZD2066 16; 2 - Placebo 10
• Patients With ≥50% Reduction From Baseline in NRS Pain Intensity Score (Responder Rate) at Day 28 (Secondary), Number, Participants: A - AZD2066 10; 2 - Placebo 5
• Patients With Patient Global Impression of Change (PGIC) Score of at Least "Much Improved" (Responder Rate) at Day 28 (Secondary), Number, Patients: A - AZD2066 10; 2 - Placebo 10
• Change in Short Form McGill Pain Questionnaire (SF-MPQ) Sensory Index From Baseline to Day 28 (Secondary), Least squares mean, Scores (units) on SF-MPQ Sensory Index: A - AZD2066 -6.39 +/- 1.278; 2 - Placebo -3.98 +/- 1.188
• Change in SF-MPQ Affective Index From Baseline to Day 28 (Secondary), Least squares mean, Scores (units) on SF-MPQ Affective Index: A - AZD2066 -1.1 +/- 0.52; 2 - Placebo -0.9 +/- 0.50
• Change in Brief Pain Inventory-Short Form (BPI-SF) Pain Severity From Baseline to Day 28 (Secondary), Least squares mean, Scores (units) on BPI-SF pain severity: A - AZD2066 -2.12 +/- 0.385; 2 - Placebo -1.25 +/- 0.360
• Change in BPI-SF Pain Interference From Baseline to Day 28 (Secondary), Least squares mean, Scores on BPI-SF pain interference: A - AZD2066 -1.98 +/- 0.376; 2 - Placebo -1.72 +/- 0.360

Adverse events

Serious adverse events by term

Other adverse events by term

Limitations and caveats: Early termination of study for safety reasons leading to fewer subjects analyzed than originally planned.

• Biljana Lilja, Study director, AstraZeneca R&D Södertälje151 85 Södertälje, Sweden
• Brett Stacey, Principal investigator, Oregon Health and Science University Comprehensive Pain Clinic, Portland, OR 97239, USA