Objectives: Female physicians in medicine are increasing, but disparities in female authorship exist. The aim of this study was to characterise factors associated with female first (FF) and female senior (SF) authorship in later phase systemic oncological clinical trials in biliary tract cancer (BTC) and identify any changes over time., Setting: Embase/Medline identified trial publications in BTC (2000-2020) were included. χ 2 tests and log regression were used (assessed factors associated with FF and SF authorship, including changes over time (STATA V.16))., Primary Outcome Measure: FF and SF authorship in later phase systemic oncological clinical trials in BTC., Secondary Outcome Measure: Any changes over time?, Results: Of 501 publications, 163 met inclusion criteria. The median percentage of female author representation in publications was 25%; there were no female authors in 13% of publications. Geographic location of the home institution of the first and senior authors was Asia (42%/42%), Europe (29%/29%), USA (24%/22%) and other (4%/6%), respectively. Overall, FF and SF author representation was 20% and 10%, respectively. The median position of the first female author was second in all the publication author lists. The phase of trial, journal-impact factor, industry funding or whether the study met its primary endpoint did not impact FF/SF author representation. More SF authors had home institutions in 'other' geographic locations (40% in 10 trials) (p=0.02) versus Asia (6%), Europe (8%) and USA (14%). There were no significant changes in FF/SF representation over time (p=0.61 and p=0.33 respectively)., Conclusions: FF and SF author representation in later phase systemic clinical trial publications in BTC is low and has not changed significantly over time. The underlying reasons for this imbalance need to be better understood and addressed., Competing Interests: Competing interests: The authors of this manuscript have the following competing interests; all outside of this submitted work: MGM has received research grant support from Servier, Ipsen, and NuCana. She has received travel and accommodation support from Bayer and Ipsen and speaker honoraria from Pfizer, Ipsen, NuCana, and Mylan. She has served on advisory boards for Incyte, Celgene, Ipsen, Sirtex, Baxalta and Astra Zeneca; all outside this submitted work. JB has received honoraria from Merck Serono, Roche, Sanofi, and Bayer; all outside this submitted work. LG has received research funding (to institution): Agios, Adaptimmune, Bayer, Merck, Macrogenics, Genentech, Novartis, Incyte, Loxo Oncology, Relay Therapeutics, QED, Taiho Oncology, Leap Therapeutics, Bristol Meyers Squibb, Nucana. Scientific Advisory Committee (to self): Agios Pharmaceuticals Inc, Alentis Therapeutics AG, H3Biomedicine, Incyte Corporation, QED Therapeutics, Sirtex Medical Ltd, Taiho Oncology Inc; Consulting (to self): Agios Pharmaceuticals Inc, Alentis Therapeutics, Genentech, Exelixis, Incyte Corporation, QED Therapeutics, Sirtex Medical Ltd, Taiho Oncology Inc; DSMC (to self): AstraZeneca; all outside this submitted work. ADW has received educational grant support from Roche, and honoraria from Bristol-Myers Squibb, Servier Suisse, Merck Sharp & Dohme, Bayer, EMD Serono, Lilly, Sanofi, Celgene, Astra Zeneca, AbbVie, Sanofi-Aventis Deutschland, SHIRE and Pfizer; all outside this submitted work. DG receives indirect research funding from Amgen, Celgene, and Pfizer and is on a data safety monitoring board for Sun Biopharma and has received honorarium from Astra Zeneca; all outside this submitted work. RS has received research funding from Merck, Exelis Pharmaceuticals, Pieris, Taiho, Rafael Pharmaceuticals and has served on advisory boards for Merck, Seattle Genetics, Exelis Pharmaceuticals, QED therapeutics, Debipharm, Agios, Clovis and Incyte; all outside this submitted work. MM receives research funding from Bayer and Lilly; all outside this submitted work. ML has received honoraria from Roche, Agios, Novartis, Astra-Zeneca; all outside of this submitted work. TB-S has received research funding (to institution): Agios, Arys, Boston Biomedical, Bayer, Amgen, Merck, Celgene, Lilly, Ipsen, Clovis, Seattle Genetics, Array Biopharma, Genentech, Novartis, Mirati, Merus, Abgenomics, Incyte, Pfizer, BMS. Consulting (to institution): Ipsen, Array Biopharma, Pfizer, Seattle Genetics, Bayer, Genentech, Incyte and Merck. Consulting (to self): AbbVie, Boehringer Ingelheim, Janssen, Eisai, Daichii Sankyo, Natera, TreosBio, Celularity, Exact Science, Sobi, Beigene, Astra Zeneca and Foundation Medicine. IDMC/DSMB (to self): Astra Zeneca, Exelixis, Lilly, PanCan and 1Globe; all outside this submitted work. RKK has received research funding (to institution): Adaptimmune, Agios, Astra Zeneca, Bayer, Bristol Myers Squibb, Eli Lilly, EMD Serono, Exelixis, Merck, Novartis, Partner Therapeutics, QED, Taiho. Consulting (to institution): Agios, Astra Zeneca, BMS. IDMC/DSMB (to self): GNE/Roche. Scientific Advisory Board (to self): GNE/Roche, Gilead, Exact Sciences, Ipsen; all outside this submitted work. JF has received research funding (to institution): Ono Pharmaceutical, MSD, Sumitomo Dainippon, J-Pharma, Yakult Honsha, AstraZeneca, Daiichi Sankyo, Eisai, Bayer, Pfizer, NanoCarrier, Kyowa Hakko Kirin, Taiho Pharmaceutical, Chugai Pharma, Sanofi, Takeda, Mochida Pharmaceutical, Astellas Pharma, Eli Lilly Japan, and honoraria from Eisai, Bayer Yakuhin, Taiho Pharmaceutical, Ono Pharmaceutical, Novartis, Yakult Honsha, Teijin pharma, Shionogi, EA pharma, Eli Lilly Japan, Takeda, Chugai Pharma, Mochida Pharmaceutical, Nihon Servier, Sanofi, Fujifilm Toyama Chemical, Nobel pharma, Pfizer, Sawai Pharmaceutical, Daiichi Sankyo, Sumitomo Dainippon, Merck Bio, Nippon Kayaku, MSD, Shire, Kyowa Hakko Kirin; all outside this submitted work. LR had received consulting fees from Amgen, ArQule, AstraZeneca, Basilea, Bayer, BMS, Celgene, Eisai, Exelixis, Genenta, Hengrui, Incyte, Ipsen, Lilly, MSD, Nerviano Medical Sciences, Roche, Sanofi; lectures fees from AbbVie, Amgen, Eisai, Gilead, Incyte, Ipsen, Lilly, Roche, Sanofi; travel expenses from Ipsen; and institutional research funding from Agios, ARMO BioSciences, AstraZeneca, BeiGene, Eisai, Exelixis, Fibrogen, Incyte, Ipsen, Lilly, MSD, Nerviano Medical Sciences, Roche, Zymeworks; all outside this submitted work. CM received grants from ONO Pharmaceutical, grants and personal fees from Yakult Honsha, grants from Eisai, grants and personal fees from MSD K.K., grants and personal fees from J-Pharma, grants and personal fees from AstraZeneca, grants from Merck biopharma, personal fees from Teijin Pharma, grants and personal fees from Taiho Pharmaceutical, personal fees from Novartis, personal fees from Abbvie; all outside this submitted work. AL has received travel and educational support from Ipsen, Pfizer, Bayer, AAA, Sirtex, Novartis, Mylan and Delcath. Speaker honoraria from Merck, Pfizer, Ipsen, and Incyte. Advisory honoraria from EISAI, Nutricia Ipsen, QED, and Roche. Member of the Knowledge Network and NETConnect Initiatives funded by Ipsen; all outside this submitted work. RH has served on advisory boards for Roche, BMS, Eisai, Celgene, Beigene, Ipsen, BTG. He has received speaker fees from Eisai, Ipsen, Mylan, PrimeOncology and has received travel and educational support from Bayer, BMS and Roche; all outside this submitted work. JK has received research funding (to institution) from AstraZeneca, Merck, Roche, Ipsen. Advisory board (to self) received from Pfizer, Merck, Celgene, AstraZeneca, Roche, EISAI, Lilly, BMS; all outside this submitted work. JV has had a consulting or advisory role for Agios, AstraZeneca, Delcath Systems, Keocyt, Genoscience Pharma, Incyte, Ipsen, Merck, Mundipharma EDO, Novartis, PCI Biotech, Pfizer, Pieris Pharmaceuticals, QED, and Wren Laboratories; Speakers’ Bureau for Imaging Equipment Limited, Ipsen, Novartis, Nucana; and received Travel Grants from Celgene and Nucana; all outside this submitted work., (© Author(s) (or their employer(s)) 2022. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)