Current and former pharmaceutical sales workers at Daiichi Sankyo Co. Ltd.’s U.S. unit on Monday brought a $100 million sex discrimination class and collective action against the drugmaker, saying they were paid less than male colleagues for doing the same work.

The six women say in their suit, filed in California federal court, that they seek to represent a class of several hundred female sales representatives from the Tokyo-based company in order to end a pattern of “pervasive gender discrimination in their workplace.”