72-Hour Knee Analgesic (NaV1.7) Shows Early Promise

Flexion Therapeutics, Inc., recently announced new positive preclinical efficacy and pharmacokinetic data for its locally administered peripheral nerve block candidate.

FX₃₀₁, a NaV1.7 inhibitor is given as a single injection to control post-operative pain. The data, which was presented in an electronic poster presentation for the American Society of Regional Anesthesia, showed a sustained analgesic effect for 72 hours with no motor function impairment.

“These compelling data bolster our excitement about the potential for FX₃₀₁to solve the issues that have plagued most pain drug candidates in the NaV1.7 inhibitor class and address a key unmet need in post-operative pain management—to provide durable and meaningful post-operative pain relief while sparing motor function,” said company President and CEO Michael Clayman, M.D.

“In contrast to liposomal bupivacaine, FX₃₀₁, through its innovative mechanism of action, provided improved analgesic effect while preserving motor function.”

The study used a validated post-operative pain model in pigs. The pigs were divided into three groups: FX₃₀₁(13 mg/mL: total dose 130 mg), liposomal bupivacaine (13.3 mg/mL: total dose 133 mg) or placebo (normal saline) in close proximity to the sciatic nerve before receiving a surgical incision. Both pain and motor function were measured during different intervals through the 72-hour mark.

Overall, the researchers said that FX₃₀₁ offered both greater pain relief and a longer duration of it through 72 hours compared to liposomal bupivacaine or placebo.

“These results support the potential for FX₃₀₁ to become a differentiated peripheral nerve block product which could enable more rapid post=operative ambulation and rehabilitation than existing nerve blocks. We look forward to advancing the FX₃₀₁ GLP toxicology studies this year and intend to initiate human trials in 2021,” Clayman added.