A CTI BioPharma treatment for a form of non-Hodgkin lymphoma has failed a clinical trial key for maintaining its approval in Europe, casting doubt on the drug’s prospects with the FDA.
Seattle-based CTI (NASDAQ: CTIC) said Monday that its drug, pixantrone, failed to meet the goal of improving progression-free survival, which is the length of time a patient lives without the disease worsening. CTI did not release additional details of the study, but said that the results will be submitted to a peer-reviewed journal for publication.
Shares of CTI fell more than 15 percent Monday morning following the announcement of the clinical trial failure.
Pixantrone was developed to fight cancer by interfering with the DNA inside cancer cells, preventing them from making more copies of DNA. This approach was meant to stop cancer cells from dividing, causing them to eventually die. In 2012, the European Commission granted conditional approval for pixantrone used alone as a treatment for adults who have aggressive B-cell non-Hodgkin lymphoma, a form of the disease that starts in the lymphocytes, or B cells.
The conditional approval in Europe required CTI to conduct an additional Phase 3 study. The study enrolled 312 patients who had relapsed after receiving the standard course of treatment for the disease, and were ineligible for a stem cell transplant. Patients in the study were randomized to receive the CTI drug in combination with another cancer treatment, rituximab, or the chemotherapy gemcitabine combined with rituximab.
Pixantrone’s clinical trial failure deals a blow to partner Servier, which had placed a big bet on the drug. In 2014, the French company paid $18.1 million up front to acquire rights to the drug worldwide except for seven European countries, along with Turkey, Israel, and the U.S. Servier pledged to pay up to $117 million more if the drug hit certain milestones. CTI also stood to gain royalties from sales of the drug. Last year, the partners amended the pact to grant Servier rights to the drug in all markets worldwide except for the U.S., where CTI retains rights.
When CTI failed to win FDA approval of pixantrone in 2010 as a treatment for non-Hodgkin lymphoma, the regulator characterized the company’s submission as resembling the results of an exploratory mid-stage study rather than the conclusions of a rigorous Phase 3 clinical trial. The FDA called on the company to conduct another study to demonstrate safety and efficacy.
CTI has has not yet resubmitted an FDA application for pixantrone but it had said that it would assess its U.S. plans for the drug following the post-authorization study required by European regulators. According to CTI’s regulatory filings, the company’s conditional approval in the E.U. requires the company to submit a report about the clinical trial by December of this year.