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. 2015 Nov 17;3:48. doi: 10.1186/s40425-015-0093-x

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© Tan et al. 2015

Open AccessThis article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.

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Fig. 3 — Evolution of Phase 2 and Phase 3 trial registration over time. Using a total of 347 studies where trial start date was available the number of phase 2 and phase 3 trial registered per year since 1999 is shown. Twenty nine phase 3 entries did not include start dates and are sorted based on continuing (ongoing or anticipated) or completed status