Lawyers for five plaintiffs who saw a $502 million jury verdict cut to $150 million last year are challenging the Texas law that caps punitive damages, saying it unconstitutionally discriminates against the old and the poor.

The constitutional challenge comes as Johnson & Johnson is hoping to convince the U.S. Court of Appeals for the Fifth Circuit to reverse the nine-figure verdict in a trial over its Pinnacle hip implants.

Texas Attorney General Ken Paxton, citing the need to curb “runaway punitive-damages awards,” has stepped in to defend the law with an amicus brief.