FDA’s top drug official, responding to criticism about the high price of breakthrough drugs, said the agency is driving toward cures for diseases like cancer and hepatitis, but there will be a transition and possibly “a big down payment” required. Both FDA drug center Director Janet Woodcock and a research advocate played up the potential decrease in societal costs and increase in patients’ quality of life in reacting to controversy around the price of the breakthrough Hepatitis C drug Sovaldi.

FDA approved Sovaldi in December to treat chronic Hepatitis C virus infection and it’s one of FDA’s initial approvals with the new breakthrough therapy designation. However, the product’s high price tag — $84,000 per regimen — has sparked criticism from payors. It has also spurred debate about the cost of paying for cures rather than chronic treatments — an argument employed by Sovaldi sponsor Gilead to defend its pricing strategy.

FDA does not regulate drug pricing and Woodcock did not specifically mention Sovaldi, but when asked about the recent controversy about the pricing of breakthrough drugs said there will be incremental progress toward cures.

“I think we have to in some ways think about this as a transition period,” she said during a panel discussion about the breakthrough designation. “We may have to put a big down payment down now to get something really good.”

She highlighted the cost to society and burden on patients in dealing with the side effects and morbidity of having Hepatitis C. “I really do believe we need to drive toward curing, but you have to have a transition period, she said. “We are driving toward a cure with hepatitis.”

Woodcock further advocated getting these drugs on the market so they could be combined with other products to drive toward cures. “In cancer, I think we have to recognized this is version 1.0, but we’re going to get there,” she said. “And to get there we can’t hold back. We can see that cure.”

Ellen Sigal, chair of Friends of Cancer Research, also highlighted the fact that there is benefit in treatments allowing patients to maintain their quality of life and productivity.

“The one very visible drug that we’re all talking about really is life saving and it also saves a huge amount of money,” she said, citing transplants and cancer. Sovaldi addresses an unmet medical need because it demonstrated efficacy in patients who could not tolerate interferon-based treatments, and who have liver cancer and were awaiting transplantation, FDA said when the drug was approved.

The breakthrough designation was created by the FDA Safety and Innovation Act. The designation expedites the development and review of drugs addressing an unmet medical need. Products receiving the designation must have clinical evidence that they are better than existing treatments and in turn receive attention from the agency’s senior managers.

Friends of Cancer Research was one of the stakeholders spearheading the creation of the program.”We’re all going to get better at this and recognize pricing is an issue, but it is really the issue of ‘Does this work and is this really helping the patient?'” Sigal said. “That’s the question you really have to be asking.”

Urte Gayko, senior vice president of global regulatory affairs for Pharmacyclics, said the company’s breakthrough drug Imbruvica has not been rejected by any public or private insurers. “In our case I think the data was very strong and that has led to full reimbursement,” she said. Imbruvica is an oral drug, so there is a copay, but there are programs in place to help with those payments, she said. The drug was initially approved in November 2013 for mantle cell lymphoma and later expanded to chronic lymphocytic leukemia.