6/28/23, 12:01 AM CALISTO Pathway Feedback Search Clinical Topics Home Studies CALISTO CALISTO Disease Deep vein thrombosis Trial question What is the effect of fondaparinux in patients with acute, symptomatic superficial vein thrombosis of the legs? Study design Multi-center Double blinded RCT Population Characteristics of study participants 64.0% female N = 3002 36.0% male 3002 patients (1918 female, 1084 male) Inclusion criteria: patients with acute, symptomatic lower limb superficial vein thrombosis at least 5 cm long, as confirmed by standardized compression ultrasonography Key exclusion criteria: cancer treatment within the previous 6 months; symptomatic or asymptomatic deep vein thrombosis, symptomatic documented PE, or documented history of superficial vein thrombosis within the previous 3 months or deep vein thrombosis or PE within the previous 6 months Interventions N=1502 fondaparinux (subcutaneous dose of 2.5 mg daily for 45 days) N=1500 placebo (matching placebo of sodium chloride SC once daily for 45 days) Primary outcome https://web.pathway.md/studies/reczZ32xkbTcRgh5c 1/2 6/28/23, 12:01 AM CALISTO Pathway Death from any cause or symptomatic pulmonary embolism, symptomatic deep vein thrombosis, or symptomatic extension to saphenofemoral junction or symptomatic recurrence of superficial vein thrombosis at day 47 5.9 % 5.9 4.4 % 3.0 % Significant decrease 1.5 % NNT = 20 0.9 0.0 % Fondaparinux Placebo Significant decrease in death from any cause or symptomatic PE, symptomatic deep vein thrombosis, or symptomatic extension to the saphenofemoral junction or symptomatic recurrence of superficial vein thrombosis at day 47 (0.9% vs. 5.9%; RR 0.15, 95% CI 0.08 to 0.26) Secondary outcomes Significant decrease in deep vein thrombosis or PE at 47 days (0.2% vs. 1.3%; RR 0.15, 95% CI 0.05 to 0.5) No significant difference in death at 47 days (0.1% vs. 0.1%; RR 1.99, 99% CI 0.18 to 21.87) Safety outcomes No significant differences in major bleeding (0.1% vs. 0.1%, p=1.00). Significant difference in serious adverse events (0.7% vs. 1.1%). Conclusion In patients with acute, symptomatic lower limb superficial vein thrombosis at least 5 cm long, as confirmed by standardized compression ultrasonography, fondaparinux was superior to placebo with respect to death from any cause or symptomatic PE, symptomatic deep vein thrombosis, or symptomatic extension to the saphenofemoral junction or symptomatic recurrence of superficial vein thrombosis at day 47. Reference Decousus H, Prandoni P, Mismetti P et al. Fondaparinux for the treatment of superficial-vein thrombosis in the legs. N Engl J Med. 2010 Sep 23;363(13):1222-32. Open reference URL https://web.pathway.md/studies/reczZ32xkbTcRgh5c 2/2