Subjects will have painful primary or post-operative intermetatarsal neuroma. Each subject will be randomly allocated to receive either ALGRX 4975 or placebo in a 1:1 ratio. Study drug or placebo will be injected into the intermetatarsal space containing a painful neuroma. Subjects will complete weekly assessments for the Average Foot Pain Severity, the 7 Interference Items of the BPI, and the number of analgesic units taken. Some subjects may be followed by monthly telephone interviews to assess their level of pain over the six-month period following treatment.~Plasma concentrations will be assessed pre-dose and post dose at 5, 10, 15, 20, 30, and 45 min and at 1, 1.5, 2, 2.5, 3 and 4 hours.~Safety will be assessed at baseline and during the study with adverse events (all visits), vital signs (Visit 2 pre and post-injection and Visit 3 or at early termination), and laboratory assessments (hematology, chemistry, urinalysis) and ECG (Screening and Visit 3 or at early termination). The injection site will be examined and assessed by a 6-point scale for erythema, edema, and hemorrhage before the injection and at 1, 2 and 4 hours after the injection. A pain on injection NRS will be assessed immediately post- injection at 15, 30, and 45 minutes and 1, 2, 3, and 4 hours after study drug administration. A sensory examination of the foot will be performed before the injection and 4 hours after the injection and at the completion of the study. If a subject has injection pain, the foot may be wrapped in ice for up to 20 minutes, analgesic medication may be provided.
Subjects will have painful primary or post-operative intermetatarsal neuroma. Study drug or placebo will be injected into the space containing the neuroma. Subjects will complete weekly assessments for severity of foot pain, a brief pain inventory, and the amount of pain medication taken. Subjects will be seen for a screening visit, a treatment visit, and two follow-up visits after treatment. The last scheduled visit is one month after treatment. Some subjects may be followed by monthly telephone interviews to assess their level of pain over the six-month period following treatment.