Gilead Shuts Down Six Zydelig Trials Following European Medicines Agency Review

March 16, 2016
By Alex Keown, BioSpace.com Breaking News Staff

FOSTER CITY, Calif. – Gilead Sciences halted six trials for its cancer drug Zydelig following concerns of adverse effects and deaths. The trials cancellation raises questions on the future of the cancer treatment as a first line treatment for cancer, the San Francisco Business Times reported this morning.

On Monday, the U.S. Food and Drug Administration issued a healthcare alert about Zydelig due to the reports of an increased rate of adverse events, including deaths. In that warning notice, the FDA said Gilead was halting the six Zydelig trials. The FDA warned healthcare professionals that Zydelig is not approved for previously untreated chronic lymphocytic leukemia.

Zydelig gained regulatory approval in the United States in 2014 for three blood cancers—for relapsed chronic lymphocytic leukemia in combination with Roche 's Rituxan (rituximab); to treat patients with relapsed follicular B-cell non-Hodgkin lymphoma; and relapsed small lymphocytic lymphoma. In Europe, Zydelig for the treatment of chronic lymphocytic leukemia in combination with Rituxan. It is approved on its own for treating follicular lymphoma, a type of non-Hodgkin lymphoma. Zydelig generated $132 million in revenue during its first full year on the market, the San Francisco Business Times said.

Although Gilead has halted the trials, the company has remained fairly tight lipped about their plans for the cancer drug. Nathan Kaiser, a spokesman for Gilead, told ABC News the company is “conducting a comprehensive review of all ongoing studies and are consulting with regulatory authorities.” Kaiser did not disclose details of the patients negatively impacted during the trials, including the number of people who may have died.

Gilead received a warning from the European Medicines Agency last week following reports of harmful side effects and infections in three clinical trials where Gilead’s drug was being used in combination with other cancer therapies. The clinical trials involved patients with chronic lymphocytic leukemia and indolent non-Hodgkin lymphoma. However, the study in chronic lymphocytic leukemia investigated combinations of medicines are currently not approved, the European Medicines Agency said on Friday. Additionally, the EMA said the studies in non-Hodgkin lymphoma included patients with disease characteristics different from those covered by the currently approved indications.

In the United States, Zydelig carries a Boxed Warning regarding serious and fatal toxicities including liver toxicity, diarrhea and colon inflammation (colitis), lung inflammation (pneumonitis) and intestinal perforation, the FDA said when it approved the drug.

Zydelig’s approval came on the heels of other CLL treatments, including Roche’s Gazyva, a follow-up drug to Rituxan, and Imbruvica, the blockbuster treatment from AbbVie and Johnson & Johnson . Imbruvica, which has estimated sales of $11 billion, was recently granted FDA approval for front-line use against CLL, which makes it the first “chemotherapy-free option for patients suffering from the disease,” Bidnessetc noted earlier this week.

Geoffrey Borges, an analyst with Leerink Partners, said issues with combinations of Zydelig and other drugs could hurt long-term growth because combo approaches are a standard way to treat cancer patient, the San Francisco Business Times reported.

Although Gilead has halted the Zydelig trials, company stock is up this morning, trading at $90.76 per share. Since the issues with Zydelig were first reported, Gilead’s stock took a slight downward turn this week, but no sharp drops in price. The company’s blockbuster hepatitis treatments are very strong and continue to drive the stock.