Donna Motsinger alleged Cosby gave her wine and a pill that left her incapacitated after picking her up in a limousine in 1972.
The women accuse the former star of using his "enormous power, fame and prestige" to target them.
Victoria Valentino claims Cosby raped her after giving her and a friend pills in 1969.
The comedian's lawyers dismiss the latest claim against him - stemming from 1975 - as a "fabrication".
Phylicia Rashad tweeted her joy at co-star Bill Cosby's sexual assault conviction being overturned.
Women who have accused the US comedian of sexual assault have been speaking out after his release.
Once a national treasure, the comedian was jailed for sexual assault but that conviction has now been overturned.
The US comedian leaves jail hours after a Pennsylvania court overturned his sexual assault conviction.
