Foucault’s Les mots et les choses at Year 50: An International Conference – Friday, April 17, 2015, 12:00pm to Saturday, April 18, 2015, 6:30pm, The Minda de Gunzburg Center for European Studies, Harvard University, sponsored by History and Theory. Vincent Descombes is the keynote speaker.

This seems a year ahead of time, as the book was published in 1966, but maybe they mean from date of finished manuscript. Thanks to Daniel Hoffman-Schwartz for the link.