Janssen Initiates CALLISTO Program to Study Xarelto for VTE in Cancer Patients

June 10, 2015—Janssen Pharmaceuticals, Inc. and its development partner, Bayer HealthCare, announced the initiation of CALLISTO, a comprehensive clinical research program for their oral anticoagulant, rivaroxaban (Xarelto), in patients with active cancer. The studies are evaluating the medicine for the prevention and treatment of blood clots in patients with a wide range of cancer types.

The companies noted that in patients with cancer, the risk of venous thromboembolism (VTE), which is a blood clot in the deep veins or the lungs, is up to five times higher compared to people the same age without cancer, and the risk magnifies in those undergoing chemotherapy.

The CALLISTO oncology research program is part of Janssen and Bayer HealthCare's broader EXPLORER clinical development program, which is evaluating patient populations being treated for blood clots or those at high risk for developing them. The CALLISTO program will encompass the field of cancer-associated thrombosis through nine studies, including seven clinical trials and two registries, across various cancer types and in more than 4,000 patients globally.

The advisory council for the program will be chaired by Alok A. Khorana, MD. Dr. Khorana is the Sondra and Stephen Hardis Chair in Oncology, Vice Chair for Clinical Services, Director of the GI Malignancies Program, Taussig Cancer Institute Cleveland Clinic, Cleveland, Ohio.  Dr. Khorana is also Co-Chair of the VTE prevention study steering committee.

The research will evaluate rivaroxaban in the following studies.

A prospective, randomized, double-blind, placebo-controlled trial will explore the primary prevention of VTE in adult patients with active cancer who are scheduled to undergo therapy to control, slow, or eradicate the cancer, such as chemotherapy, in the outpatient setting. Endpoints include the incidence of VTE and major bleeding events. The trial will enroll patients at high risk of developing blood clots based on their modified Khorana risk score (a recognized scoring system for predicting blood clots in patients with cancer) and will study patients with solid cancers, including but not limited to those of the pancreas, lungs, stomach, colon, rectum, bladder, breast, kidney, and ovary, and those with lymphoma. Because one-third of all VTE events are asymptomatic, the study will follow patients over a 6-month period and use periodic medical imaging to evaluate the occurrence of “silent” clot formation, which will help identify when these events are happening.

Three studies will compare rivaroxaban to the low-molecular-weight heparin dalteparin, the current standard of care for the treatment of VTE in patients with active cancer. Endpoints include the incidence of recurrent events and major bleeding. The studies will enroll patients with various cancer types and will include two randomized studies and one quality-of-care improvement analysis.

Two observational registries, one in the United States and one outside the United States, will follow various outcomes of cancer patients with blood clots who are treated with an anticoagulant to better understand the treatment of VTE and the prevention of recurrent events in this patient population. A substudy will assess the treatment of blood clots specifically in patients with cancer who must undergo surgical procedures.

Three additional studies will focus on important clinical aspects, such as concomitant use of rivaroxaban with standard cancer therapies, like chemotherapy, and assessment of a bridging strategy for patients taking rivaroxaban or low-molecular-weight heparin in instances when chemotherapy-induced vomiting makes oral therapies challenging.

The EXPLORER program is evaluating patients with chronic heart failure, coronary artery disease, peripheral artery disease, acute coronary syndrome, embolic stroke of undetermined source, and now, active cancer. By the time of its completion, more than 275,000 patients will have participated in the clinical development program, other completed and ongoing clinical trials, investigative registries, and noninterventional studies, stated Janssen.