The purpose of this study is to provide replicated evidence of safety and efficacy of 100 mg ketoprofen in Diractin®.

The study will investigate safety and efficacy of Diractin® at relieving signs and symptoms of knee OA, including the primary endpoint of patient assessment of pain.

Inclusion Criteria:

• Informed consent signed and dated
• Age > 45 years
• Class I-III OA of the knee and subject meets American College of Rheumatology (ACR) clinical classification criteria for osteoarthritis of the knee

Exclusion Criteria:

• Skin lesions or dermatological diseases in the treatment area
• Directly or indirectly involved in the conduct and administration of this study
• Received any investigational medicinal product within 30 days prior to Screening Visit or participation in any previous clinical study with Diractin®
• Pregnancy or lactation
• Residents of psychiatric wards, prisons or other state institutions
• Malignancy within the past 2 years
• Depressive disorders requiring treatment with tricyclics, treatment with other antidepressants must be stable for 3 months prior to screening and throughout the study
• Epilepsy
• Schizophrenia
• Neuropathic pain and any other pain condition requiring chronic use of pain medication
• Known hypersensitivity or allergy (including photoallergy) to NSAID´s including ketoprofen and to ingredients of the IMP
• Preexisting asthma or bronchospasm after taking aspirin or other NSAIDs
• Unable to discontinue analgesic therapy including opioids, NSAID´s, tramadol, muscle relaxants, gabapentin, pregabalin, duloxetine, venlafaxine, capsaicine or other drugs approved or used for the treatment of pain for the duration of the study