The main character was Greer Nelson, a widow who had her physical abilities scientifically enhanced to their fullest potential and donned a catlike costume to fight crime. The first issue was written and pencilled by women - Linda Fite and Marie Severin - and coincided with a handful of other Marvel titles featuring female characters, including Night Nurse and Shanna the She-Devil. Unfortunately, none of these (probably lacking support from the publisher) lasted more than five issues.
The character of Greer Nelson was changed into a super-heroine called Tigra in Giant-Size Creatures #1, and would go on to have plenty of other adventures.
Interestingly, the Cat's costume was taken over by Patsy Walker, a teen-humor character who first appeared in Marvel's Miss America Magazine in 1944; she would have her own title lasting for two decades, starting in 1945. Calling herself Hellcat, she would have several adventures with the superhero teams the Avengers and the Defenders.
Note: This title is often referred to as Claws of the Cat.