Baxter International and CTI BioPharma Corp. announced that its experimental blood cancer drug met its primary endpoint in a late-stage study.
The companies announced top-line results for the primary endpoint from PERSIST-1, a Phase III registration clinical trial evaluating pacritinib, an oral JAK2/FLT3 multikinase inhibitor, for the treatment of patients with primary or secondary myelofibrosis, a rare bone marrow cancer. The companies said that the study met its primary endpoint, the proportion of patients achieving a 35 percent reduction in spleen volume from baseline at week 24, in the intent-to-treat population with statistically significant activity in patients irrespective of their initial platelet count, including those with thrombocytopenia, a severe and life-threatening condition.
There was also a reduction in transfusion dependence in a group of 50 patients. According to the companies, the safety profile in the study was consistent with prior mid-stage trials. Three patients discontinued therapy and nine patients required dose reduction for diarrhea.
“Despite the introduction of JAK2 inhibitors as effective therapies for patients with myelofibrosis, there remains a treatment gap for patients with disease-related or treatment emergent thrombocytopenia. The currently approved drug may require dose titration to less effective doses in this patient population, thus limiting our ability to effectively treat them. Results from the PERSIST-1 randomized trial demonstrate that pacritinib could address this unmet medical need,” said Claire Harrison, MD, Consultant Hematologist, Guy’s and St. Thomas’ NHS Foundation Trust, Guy’s Hospital, London, United Kingdom and one of the principal investigators for PERSIST-1. “It is encouraging to see that patients were able to receive therapeutic doses of pacritinib over a long period of time irrespective of their baseline platelet or red blood cell count while having the therapeutic benefit in reduction in spleen volume and disease-related symptoms and improvement in transfusion dependency.”
The news sent CTI BioPharma’s shares up 24 percent in premarket trading.
Pacritinib, one of four cancer compounds being developed by CTI BioPharma, is a JAK2/FLT3 multikinase inhibitor, which works by disrupting the production of a protein that is key to regulating the immune system and contributes to the growth of cancer cells.
“The positive top-line results illustrate the potential of this investigational treatment to become a valuable new treatment option for this challenging disease. Pacritinib is an important component of Baxter’s growing oncology portfolio, and we look forward to partnering with CTI BioPharma to share these results with physicians and discussing next steps with regulatory agencies,” said David Meek, Head of Oncology at Baxter BioScience.
In 2013, Baxter paid CTI $60 million upfront, with a promise of $112 million in development milestones for rights to the drug if approved. Under the deal, CTI retains exclusive commercialization rights in the US, while Baxter has exclusive rights ex-US.
Myelofibrosis is a serious and life-threatening chronic bone marrow disorder caused by the accumulation of malignant bone marrow cells that triggers inflammation and scars the bone marrow. The replacement of bone marrow with scar tissue limits its ability to produce red blood cells, prompting the spleen and liver to take over this function. Patients with the disease experience symptoms including enlargement of the spleen, anemia, extreme fatigue and pain. The disease affects roughly 18,000 patients in the US, with a median age of diagnosis of 64 years old.
Source: CTI BioPharma Corp.
Last updated: 3/9/15; 10:00am EST