AbbVie Suspends Five Clinical Trials of Leukemia Therapy

AbbVie Inc., the drug company that split off from Abbott Laboratories at the start of the year, suspended five studies on its experimental leukemia and lymphoma medicine after two patient deaths.

The patients died from tumor lysis syndrome, said Tracy Sorrentino, a spokeswoman for North Chicago, Illinois-based AbbVie. The complication stems from the rapid destruction of malignant cells after treatment that can trigger acute kidney failure. It occurs most often with large tumors such as those found in leukemia and lymphoma patients, according to the National Institutes of Health.

AbbVie is looking for new products to diversify beyond its best-selling arthritis drug Humira. ABT-199 is one of the company’s most-promising new compounds and was slated to start the final round of testing usually required for U.S. regulatory approval this year.

“We have every expectation that these trials will come off the partial clinical hold and we’ll be able to initiate Phase 3 trials in 2013 as planned,” she said. “ABT-199 is a highly-potent agent and can result in the tumors reducing really quickly,” she said. “We are working to refine the dose.”

After the complication was discovered, AbbVie and its partner, Roche Holding AG, suspended the dose-escalation portion of the studies to determine the amount of drug that is safest and most effective, Sorrentino said. The risk stems from the drug’s potency and can be managed if the dose is carefully controlled, she said.

Suspended Studies

The trials are in patients with relapsed or hard-to-treat non-Hodgkin’s lymphoma, chronic lymphocytic leukemia and small lymphocytic leukemia, according to the U.S. website Patients originally given the medicine are still able to take it in the trials, Sorrentino said. A study in women with systemic lupus erythematosus is still under way.

The drug, a BCL-2 inhibitor, established a strong “proof of concept” and has shown activity against blood cancers in early trials, AbbVie Chief Executive Officer Richard Gonzalez said on a conference call with investors on Jan. 30.

The suspensions of the trial were mentioned by company executives in response to analysts’ questions on the conference call. One of the patient deaths was reported earlier today by Biotech Strategy Blog.

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