Family members and a lawmaker who is sponsoring a state Senate bill announced their intentions Monday at a Capitol news conference.
The bill would permit doctors to prescribe the marijuana oil extract.
The families cite a recent independent poll saying 85 percent of Pennsylvania voters believe doctors should be able to prescribe medical marijuana to adults.
The governor's office says Corbett and his staff have met with families on the issue, but he believes federal drug regulators, not states, should be making such policy decisions.
Twenty states have legalized it.