Just hours before one of its executives is set to testify at a Congressional hearing to review insulin pricing, Sanofi (SNY) on Wednesday offered a program that will lower the cost of the diabetes treatment to $99 a month for uninsured patients and others who pay cash in the U.S.

Under the plan, the drug maker maintained patients can buy up to 10 boxes of insulin pens or vials with a valid prescription, beginning in June, and expands a program that began a year ago in which patients were paying $99 for each vial of insulin and $149 for each pack of insulin pens.