Tiopronin delayed-release tablets available in US for patients with cystinuria

Tiopronin (VENXXIVA) delayed-release tablets are now available in the US for patients with cystinuria, Cycle Pharmaceuticals Limited announced in a news release.¹

A 2019 study showed that patients taking tiopronin reported better health-related quality of life than those not taking tiopronin.

Tiopronin delayed-release tablets are FDA approved—in combination with high fluid intake, alkali, and diet modification—for the prevention of cystine stone formation in adult and pediatric patients 9 years of age and older with severe homozygous cystinuria who are not responsive to these measures alone. The tablets are indicated at the dose levels of 100 mg and 300 mg.

This announcement follows the successful launch of generic tiopronin delayed-release tablets, which was reported in May 2024.² Both launches were achieved through a partnership between Cycle and Torrent Pharmaceuticals, with support from Vanscoy Rare Pharmacy as the distribution partner.

Eligible patients taking tiopronin tablets also have access to Cycle’s Therapeutics program, Cycle Vita, which provides financial, product, and clinical education programs tailored to the needs of each patient.

According to Cycle Pharmaceuticals, “Cycle Vita and Vanscoy Rare will actively work with patients and clinics to support the transition of patients prescribed with generic tiopronin delayed-release tablets to VENXXIVA, and continue their access to Cycle Vita’s patient support services.”

Data on tiopronin

A study published in Urolithiasis in 2020 showed that patients taking tiopronin reported better health-related quality of life (HRQOL) compared with patients not taking tiopronin.³

For the study, a cross-sectional survey was conducted on patients who were cystinuria kidney stone formers to assess their HRQOL. The authors noted, “Patients on tiopronin treatment were recruited through the ‘Thiola Total Care Hub,’ a specialty pharmacy used to dispense tiopronin, and compared with patients not taking tiopronin (non-tiopronin group) who were identified from the Cystinuria Contact Registry at New York University School of Medicine.”

HRQOL was assessed using the Wisconsin stone quality of life (WISQOL) questionnaire and the short form-36 version 2 (SF-36v2) questionnaire.

In total, the survey was completed by 312 patients, of whom 267 were taking tiopronin and 45 were not. The tiopronin arm was composed of 144 male patients and 123 female patients, with a mean age of 49 years. The non-tiopronin arm included 10 male patients and 35 female patients with a mean age of 48 years. Across both groups, 24% of respondents used pain medication, with similar rates seen in each arm (tiopronin: 10.5%; non-tiopronin: 15.6%).

Overall, patients in the tiopronin arm reported higher scores on all 4 domains of the WISQOL questionnaire (P < .001). Specifically, patients taking tiopronin had better mean scores for social impact (77.6 vs 69.7), emotional impact (68.3 vs 60.0), disease impact (65.8 vs 59.3), and vitality impact (67.5 vs 58.3).

Similar results were seen on the SF-36v2 questionnaire, where patients in the tiopronin arm reported higher scores on all domains aside from physical functioning. Specifically, patients in the tiopronin arm reported better scores in regard to role physical, bodily pain, general health, vitality, social functioning, and role emotional (all P < .001). In the physical functioning domain, the mean scores were 49.3 in the tiopronin arm vs 49.2 in the non-tiopronin arm (P = .349).

Composite SF-36v2 scores were also higher in the tiopronin arm. The mean physical composite score was 49.5 in the tiopronin arm vs 47.5 in the non-tiopronin arm (P < .001). Similarly, the mean mental composite score was 49.6 in the tiopronin arm compared with 44.4 in the non-tiopronin arm (P < .001).

Based on these data, the authors concluded, “Treatment with tiopronin may provide a positive effect on patients’ HRQOL concerns. Healthcare professionals should continue to monitor patients on tiopronin therapy and partner with patients on issues related to treatment management and disease control.”

REFERENCES
1. New US product launch, VENXXIVA (tiopronin) Delayed-Release Tablets for the treatment of cystinuria. News release. Cycle Pharmaceuticals Limited. Published online and accessed March 18, 2025. https://cyclepharma.com/news/venxxiva-tiopronin-tablets-launch/

2. New tiopronin delayed-release tablets launch with patient support in the US. News release. Cycle Pharmaceuticals Limited. May 7, 2024. Accessed March 18, 2025. https://cyclepharma.com/news/new-tiopronin-delayed-release-tablets-launch/

3. Modersitzki F, Goldfarb DS, Goldstein RL, Sur RL, Penniston KL. Assessment of health-related quality of life in patients with cystinuria on tiopronin therapy. Urolithiasis. 2020;48(4):313-320. doi:10.1007/s00240-019-01174-6