SantoSolve AS (OSLO, Norway), a privately held biopharmaceutical company focused on strontium-based therapies for the treatment of pain and inflammatory lesions, announced positive results for 2PX, its topical analgesic formulated for subdermal pain treatment in patients with osteoarthritis (OA) of the knee.

The multicenter, double-blind, placebo-controlled phase II study evaluated 84 patients in Norway, and was designed as a two-arm, 4 + 4 week crossover trial. During the trial, 2PX or placebo was self-administered twice-daily with a proprietary applicator to the site of pain. The study met its prespecified primary endpoint of reducing pain from baseline to study week 4 (P = .038), as measured by WOMAC subscale for pain. A 35% reduction in pain from baseline after 4 weeks of 2PX was observed, compared with a 21% reduction in the control group. No statistically significant differences were found for other efficacy variables in the 4-week parallel group comparison, despite consistent unidirectional trends in favor of the compound.

In the cross-over study phase, 2PX was significantly more efficacious than placebo for WOMAC pain, physical functioning, total scores, pain relief, and intensity, but insignificantly effective for stiffness. The overall safety profile of the 2PX compared with placebo was good, except that erythema occurred more often with the compound.

SantoSolve is currently conducting additional preclinical work to allow long-term administration of the compound. The company, upon completion of the work, will be in a position to initiate phase III trials with long-term administration in OA. In open-label phase II clinical trials, 2PX showed strong analgesic effect in both nociceptive and neuropathic pain conditions.