Stemmler 2011 A.

Study characteristics
Methods	Randomised multicentre phase II trial. Accrual between 2003 and 2006. Groups comparable at baseline in all regards except menopausal status.
Participants	Overall, a total of 141 participants (91 in Arm A + Arm B) with histologically confirmed metastatic breast cancer. In mTNBC subgroup there were 36 participants (9 in Arm A, 12 in Arm B and 15 in Arm C). The sample size of Arm B was halved for analysis. 100% metastatic breast cancer.
Interventions	GemVin vs GemCis. ARM A: GemVin: Gemcitabine 1000 mg/m2 + vinorelbine 25 mg/m2. ARM B: GemCis: Gemcitabine 1000 mg/m2+ cisplatin 30 mg/m2. Treatment for a maximum of six (3 week) cycles.
Outcomes	OS (no results provided for mTNBC subgroup). TTP (no results provided for mTNBC subgroup). OTRR (proportions and exact binomial confidence intervals reported; these were used to calculate numerators and denominators for OTRR fractions). Toxicity (no results provided for mTNBC subgroup).
Notes	No reported deaths due to toxicity. OTRR: 11.1%, 95% CI: 0.3–48.3 (GemVin); 58.3%, 95% CI: 27.7–84.8 (GemCis). Randomisation procedure not stated ‐ just reported as "randomised". All randomised participants were analysed in time‐to‐event analyses (ITT). "This study was supported by Lilly GmbH Germany." This study was included in Egger 2017 but the reported mTNBC subgroup results for OTRR were inadvertently not included.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Method of random sequence generation not reported. Stated as "randomised" only.
Allocation concealment (selection bias)	Unclear risk	Not stated.
Blinding of participants and personnel (performance bias) All outcomes	High risk	Registered as 'open‐label' trial (https://www.clinicaltrials.gov/ct2/show/NCT00480597).
Blinding of outcome assessment (detection bias) (overall survival)	Low risk	Open‐label study. Unlikely that assessment of OS would be influenced by lack of blinding.
Blinding of outcome assessment (detection bias) (outcomes other than overall survival and quality of life)	Unclear risk	Blood and biochemistry tests, and imaging took place during therapy. No details were provided on whether there was a central (independent) evaluation team for assessing tumour response rates.
Incomplete outcome data (attrition bias) (time‐to‐event outcomes)	Low risk	In the overall analysis (not mTNBC specific), all 45 and 46 participants randomised to intervention and control groups, respectively, were analysed in time‐to‐event analyses (intent‐to‐treat analyses).
Incomplete outcome data (attrition bias) (binary outcomes)	High risk	In the overall analysis (not mTNBC specific), 10 of 45 and 9 of 46 participants randomised to intervention and control groups, respectively, were not assessed/assessable for tumour response (20.3% of all randomised participants). 0 of 45 and 4 of 46 participants randomised to intervention and control groups, respectively, were not included in the safety population for evaluating toxicities (5.8% of all randomised participants).
Selective reporting (reporting bias)	High risk	In the overall analysis (not mTNBC specific), all outcomes in the trial report were listed in the ClinicalTrials.gov record and vice versa. However, only OTRR results were reported for mTNBC specific results (https://www.clinicaltrials.gov/ct2/show/NCT00480597).
Other bias	Low risk	None identified.