Incyte, Novartis myelofibrosis trial meets goal

* Spleen size reduced in 28.5 pct of patients at 48 wks

* Side effects include anemia, low platelet counts


By Deena Beasley

CHICAGO (Reuters) – A second pivotal trial of ruxolitinib, developed by Incyte Corp and Novartis, met its goal of showing that the drug significantly reduces spleen size in myelofibrosis patients.

The rare, but potentially deadly, blood cancer is characterized by bone marrow failure, enlarged spleen and debilitating symptoms, including fatigue and pain.

The Phase 3 trial, known as COMFORT II, showed that after 48 weeks ruxolitinib reduced spleen size by at least 35 percent in 28.5 percent of patients, compared with no patients treated with best available therapy.

The drug was also associated with improvement in overall quality of life measures, functioning and symptoms.

The most common side effects for ruxolitinib patients were low platelet counts (8.3 percent) and low hemoglobin levels (42.4 percent).

“Anemia is dependent on the dose of drug used, so it can be easily managed with a reduction of the dose whenever necessary,” said Dr. Alessandro Vannucchi, professor of hematology at the University of Florence and the study’s co-author.

One patient in each arm of the trial dropped out due to thrombocytopenia, but there were no discontinuations due to anemia.

Researchers said one patient’s death may have been related to ruxolitinib treatment.

The trials were not designed to measure survival, but “of course patients were compared,” said Dr. Vannucchi. “At present we are not able to say that the drug can impact survival.”

The first trial, COMFORT I, results of which were announced previously, showed that 42 percent of patients who received ruxolitinib achieved at least a 35 percent reduction in spleen volume at 24 weeks, compared with 0.7 percent of patients given a placebo.

The drug is designed to block abnormal signaling in the Janus kinase (JAK) pathway, which regulates blood cell production, and is activated in myelofibrosis patients.

“There is no effective therapy,” said Dr. Vannucchi. “This is really an exciting drug in this field … I am very convinced that it will be an important chance for these patients.”

Novartis and Incyte said the studies provide the basis for worldwide regulatory filings starting in the second half of this year.

Analysts, on average, have predicted annual ruxolitinib sales of $592 million for Incyte and $357 million for Novartis by 2015, according to Thomson Pharma.