Sen. Charles Grassley (R-Iowa) continued his campaign over the high price of epinephrine injectors with a letter to Kaléo Pharmaceuticals, producer of an EpiPen rival.

Kaléo’s Auvi-Q lists for $4,500 for a two-pack, although consumers without insurance will pay only $360, Grassley noted, in a letter. This pricing policy raises similar concerns to those for the EpiPen.

While some patients “pay effectively nothing” for the Auvi-Q, the pricing structure “may simply shift the burden and cost to another entity within the health care system,” Grassley said.