UPDATED: Europe approves Gilead's cancer drug Zydelig amid challenging pricing environment

Less than two months after the FDA approved Gilead Sciences' ($GILD) first cancer drug, Zydelig, the European Medicines Agency (EMA) has followed suit, green-lighting the drug for use in treating two blood cancers. The approval puts Gilead well on track to meet analyst expectations that Zydelig (idelalisib) will be hauling in $1.2 billion in annual sales by 2020, though there's little doubt Gilead will face pressure from European health agencies to keep a lid on the new drug's price.

Zydelig is among a new class of drugs known as PI3k inhibitors. It was approved in the U.S. to treat chronic lymphocytic leukemia (CLL), relapsed follicular B-cell non-Hodgkin lymphoma (FL) and small lymphocytic lymphoma. The EMA approved the drug for use in CLL and FL. In CLL, the approval was supported by late-stage data showing that when added to Roche's ($RHHBY) Rituxan, Gilead's drug prevented the cancer for progressing for twice as long as Rituxan alone, according to the Gilead statement. The EMA approved the drug for treating FL based on Phase II data showing an overall response rate of 54%.

"Although chemo-immunotherapy is initially used to treat both CLL and FL, relapse is common and many patients run out of treatment options to treat the disease as it progresses," said Peter Hillmen, a professor and hematologist at Britain's Leeds Teaching Hospitals NHS Trust, in a statement released by Gilead. "Thus, Zydelig is a welcomed treatment option that offers a new approach in the management of these cancers."

No word yet on how Gilead plans to price Zydelig in Europe, but the company will likely face questions, particularly from the National Institute for Health and Care Excellence (NICE), the U.K.'s drug-price watchdog, which decides what drugs will be covered by the government. NICE has said "no" to several pricey cancer drugs lately, including Roche's Kadcyla for breast cancer, and Johnson & Johnson's ($JNJ) prostate cancer treatment Zytiga.

In September, NICE threatened to bypass drugmakers altogether when assessing the value of new drugs and instead go to the EMA to obtain clinical trial data.

Gilead itself has gotten some pushback from NICE on its new hepatitis C treatment Sovaldi. The drug is priced at $57,000 a course in the U.K.--much lower than its $84,000 price in the U.S.--but NICE still went back to Gilead in June and asked for more evidence that Sovaldi is worth its price. NICE issued a provisional OK in August and is expected to release its final appraisal on Sovaldi later this year.

In the U.S., analysts are reporting that Gilead has priced Zydelig lower than its top competitor, Johnson & Johnson's Imbruvica (ibrutinib)--$7,200 per month vs. $8,200. When added to Rituxan or another cancer treatment, however, the cost of Gilead's therapy could rise to $12,000, they estimate.

Zydelig won't be competing for market share on price alone. Analysts warn that in the U.S., pickup could be slowed by a black-box warning on the product that highlights such side effects as colitis, lung inflammation and potential fatal liver problems. Imbruvica doesn't have a black box. And there's more competition to come: AbbVie's ($ABBV) Rituxan add-on, ABT-199, is in late-stage development.

- here's Gilead's statement

Editor's Note: The story was updated to reflect the most recent status at NICE for Sovaldi.