ASH: Pharmacyclics' ibrutinib seizes center stage with promising leukemia results

Pharmacyclics ($PCYC) continued its drumbeat of positive data for its would-be chronic lymphocytic leukemia blockbuster ibrutinib, with large majorities of two groups of older patients responding to the drug. Partnered with Johnson & Johnson ($JNJ) in a major market deal, Pharmacyclics demonstrated fresh evidence that ibrutinib could control malignancies in patients who were both treatment naïve and unresponsive to other meds.

The drug is designed to inhibit Bruton's tyrosine kinase--or BTK--shutting down and eliminating leukemia cells without inflicting widespread damage on healthy cells. And the data backs up J&J's decision to ink a $975 million licensing deal--with a hefty $150 million upfront gamble--for one of the most promising late-stage cancer drugs now in the pipeline. Analysts say the treatment has the potential to earn $5 billion a year, according to a report in Bloomberg.

Here's why: Investigators concluded that 71% of untreated patients demonstrated a complete or partial response, compared to 67% of a group of relapsed patients and half of the elderly subjects in a particularly high-risk cohort. And after nearly two years of follow-up, the disease had not progressed  in 96% of the previously untreated group, compared to 76% of the relapsed and high-risk patients. And while a laundry list of nonsevere side effects were recorded, the trial also underscored the drug's promising ability to treat the disease without inflicting older patients with severe toxicity.

In another study, ibrutinib combined with Rituxan was effective in 83% of patients. And all but two of the 40 patients in that trial continued without disease progression after three and 6 months of follow-up.

"If we can replicate these high survival rates and good tolerability with ibrutinib through larger scale Phase III studies, we may find it to be an extremely valuable new therapy for not just elderly, but for all CLL patients," said John C. Byrd, M.D., the lead author of the ibrutinib study, in a press release.

- here's the press release
- read the report from Bloomberg

ALSO: In a 12-month follow-up of Ariad's ($ARIA) pivotal study for ponatinib, investigators reported that the therapy had erased signs of chronic myeloid leukemia in about half of patients who were no longer responding to other medications. More than half of the patients getting the drug, meanwhile, achieved a "major response." The new data underscores Ariad's excellent odds of getting an FDA approval for the drug by the March 27 PDUFA date, setting up its first drug launch in the U.S. Story

PLUS: Celldex Therapeutics' antibody drug conjugate, CDX-011, produced positive results in a mid-stage study for advanced breast cancer. Company execs tell TheStreet that they plan to get regulators to sign off on a confirmatory study that can pave the way to an accelerated approval. Report

PLUS: Boehringer Ingelheim says that it garnered positive data from its Phase II study of volasertib in newly diagnosed patients with acute myeloid leukemia, setting the stage for a Phase III study to launch in early 2013. Release