Safety and Efficacy Study of GRT6005 in Patients With Osteoarthritis (OA) Knee Pain

Inclusion Criteria:

- Diagnosis of osteoarthritis (OA) of the knee

- OA knee pain present for at least 3 months

- OA knee pain is the predominant (ie, most painful) pain condition

- Patients require medication on at least 4 of 7 days per week to treat OA knee pain for
at least 1 month.

- Dissatisfaction with current OA knee pain treatment and willingness to stop taking all
pain medications except for the study drug and allowed rescue medication

- Average daily pain rating of at least 5 on a 0 to 10 point numerical rating scale
during the 1 week prior to randomization

- Female patients either postmenopausal, surgically sterile or practicing a medically
acceptable method of contraception

- Male patients either status post-bilateral vasectomy or using barrier contraception

Exclusion Criteria:

- Knee pain due to a disorder other than OA

- Other pain that can confound the assessment of, or contribute to, pain at the
reference knee

- Surgery at the reference knee within 6 months of Screening or a history of joint
replacement surgery at the reference knee

- Trauma to the reference knee within 6 months of Screening with active symptoms

- Steroid injections in the reference knee within 3 months of Screening

- Hyaluronic acid injections in the reference knee within 6 months of Screening

- Body Mass Index > 40 kg/m2

- Patient with any protocol-excluded or clinically significant medical, surgical, or
medication history that would limit the patient's ability to complete or participate
in this clinical trial or could confound the study assessments