Desmodium styracifolium Total Flavone Capsules for Urolithiasis: A Phase 3 Randomized Clinical Trial.

The short version

This phase 3 randomized trial of 606 adults in China explored whether Guang Jing, a capsule made from the total flavonoids (plant pigment compounds with antioxidant activity) of the traditional Chinese herb Desmodium styracifolium, helps ureteral stones pass out of the body. A ureteral stone is a mineral deposit lodged in the tube that carries urine from the kidney to the bladder. Treatment that encourages passage is called medical expulsive therapy, and the authors note that alpha-blocker drugs, the guideline option, have shown mixed results in large trials. No oral medicine is currently approved for urolithiasis, and Guang Jing is already approved in China for ureteral stones. Participants were adults aged 18 to 70 with a newly diagnosed ureteral stone of 5 to 10 mm and a traditional Chinese medicine pattern called damp-heat accumulation (urethral burning, lower back pain or blood in the urine). At 34 hospitals, three of every four received 3 capsules (0.6 g) of Guang Jing three times daily for 28 days, and the rest received identical placebo capsules. Neither participants nor investigators knew who received which. Passage was confirmed by CT scan on day 28, read by blinded investigators. By day 28, 44.6% of the Guang Jing group (204 of 457) had passed their stone versus 33.8% of the placebo group (50 of 148). That is a 10.9 percentage point difference (relative risk 1.32, so passage was about one-third more likely; P = .03). At day 14 the groups did not differ significantly (29.1% vs 22.3%; P = .14), and stone movement distance was almost identical (29.5 vs 29.7 mm). Among those with 0.6 to 1.0 cm stones, passage was 37.2% vs 24.4% (a larger gap in the bigger stones), and 66.2% of Guang Jing participants with distal stones, the lower part of the ureter near the bladder, passed them. Adverse events were similar (19.3% vs 18.2%, meaning side effects were about as common with the capsule as with placebo), with no medication-related serious events. The authors describe the absolute benefit as modest, since 55.4% of the Guang Jing group did not pass a stone by day 28. The trial enrolled a fairly uniform group, mostly from southern China, and the subgroup results were exploratory. The authors state that this homogeneous population limits how far the findings generalize, and that CT slice thickness may have missed small differences in stone movement. They plan further trials in Europe and North America and call for studies to identify who benefits most and to establish how the extract works in humans.

Key findings

• In a phase 3 trial of 606 adults in China with 5 to 10 mm ureteral stones, 44.6% of those taking Guang Jing (a capsule of total flavonoids, plant compounds with antioxidant activity, from Desmodium styracifolium) passed their stone within 28 days, compared with 33.8% on placebo (P = .03).
• The absolute difference was 10.9 percentage points (95% CI 2.0 to 19.7), and 55.4% of the Guang Jing group still had no confirmed stone passage by day 28.
• Stone passage at day 14 and the distance stones moved did not differ between groups, and the larger-stone and distal-stone subgroup results were exploratory.
• Adverse events were similar with Guang Jing and placebo (19.3% vs 18.2%), and the 2 serious events in the Guang Jing group were judged unrelated to the capsule by the investigators.
• All participants were Asian adults recruited at 34 sites in China, so the authors state that generalizability to other populations is untested.

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