TRAFFIC.

Methods	Study design: stated as randomised, placebo‐controlled, double‐blind, phase II trial. Multicentre trial (different hospitals), randomisation code: 1:1:1 Recruitment: no data (USA)
Participants	People with moderate‐to‐severe intermittent claudication (N randomised and received first dose = 190, planned N = 180) Age (mean): 67 years (placebo), 65 years (single‐dose), 69 years (double‐dose) Sex (N males/females): 73%/27% (placebo), 71%/29% (single‐dose), 82%/18% (double‐dose) Severity: ABI: in all groups mean levels between 0.5 and 0.6 (data from figure)
Interventions	FGF‐2: recombinant fibroblast growth factor‐2 2 × 30 µg/kg FGF‐2 (days 1 and 30); 61 participants received 1 dose, 53 all doses 1 × 30 µg/kg FGF‐2 (day 1), placebo (day 30); 66 participants received 1 dose, 61 all doses 2 × placebo (days 1 and 30); 63 participants received 1 dose, 60 all doses As 2 intra‐arterial infusions (15 µg/kg FGF‐2 per limb), each over 10 minutes
Outcomes	Change in peak walking time from baseline to 90 days (primarya), Peak walking time change from baseline to 180 days Claudication onset time and ABI change from baseline to 90 and 180 days Quality‐of‐life change from baseline to 30, 90, and 180 days Safety (adverse events, incl. changes in retinal examination)
Notes	aDifference between 3 groups based on analysis of variance
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Randomisation codes were generated
Allocation concealment (selection bias)	Low risk	Allocation by sequentially opening sealed assignment envelopes
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Blinding procedure is not explicitly reported
Blinding of outcome assessment (detection bias) Objective outcomes	Low risk	Outcome measurement is not likely to be influenced by lack of blinding
Blinding of outcome assessment (detection bias) Subjective outcomes	Unclear risk	Blinding procedure is not explicitly reported
Incomplete outcome data (attrition bias) Death	Low risk	Only few missing data, which are balanced in numbers across intervention groups
Incomplete outcome data (attrition bias) Limb amputation	Unclear risk	Results not explicitly reported
Incomplete outcome data (attrition bias) Ulceration	Unclear risk	The study did not address this outcome
Incomplete outcome data (attrition bias) Rest pain	Unclear risk	The study did not address this outcome
Incomplete outcome data (attrition bias) Walking ability	Low risk	N missing data are low (< 15%). Reasons for missing are reported and balanced across groups
Incomplete outcome data (attrition bias) Haemodynamic measures	Low risk	N missing data are low (< 15%). Reasons for missing are reported and balanced across groups
Incomplete outcome data (attrition bias) Adverse events /severe complications	Low risk	Only few missing data (no aggregate data)
Selective reporting (reporting bias)	Unclear risk	The study protocol is not available, results for limb amputation not reported
Other bias	Low risk	The study appears to be free of other sources of bias