Study: Caplacizumab not cost effective for treating thrombotic thrombocytopenic purpura

In a new study by Yale Cancer Center (YCC) researchers, the drug caplacizumab is shown not to be cost-effective in treating thrombotic thrombocytopenic purpura (TTP) when added to the standard-of-care. The findings are being presented today at the virtual 62nd American Society of Hematology (ASH) Annual Meeting & Exposition.

We performed the first-ever cost effectiveness analysis in acquired TTP and found that the addition of caplacizumab to standard of care treatment is not cost effective at its current drug pricing. This raises the question: Are we doing the right thing for our patients, for our community, and for our health system?"

George Goshua, MD, lead author of the study and clinical fellow in the Hematology/Oncology fellowship training program at YCC

TTP is a life-threatening, rare blood disorder where blood clots form in small blood vessels throughout the body. The clots can limit or block the flow of oxygen-rich blood to the body's organs, such as the brain, kidneys, and heart. Caplacizumab, the first drug approved by the U.S. Food and Drug Administration for treatment of TTP, is used in combination with plasma exchange and immunosuppressive therapy to treat the disorder.

In the study, to analyze the cost effectiveness of adding caplacizumab to standard of care (SOC) in acquired TTP, Goshua and his colleagues developed several cost models using data from two major clinical trials studying TTP (TITAN and HERCULES). The models incorporated the cost of caplacizumab and other SOC treatments for TTP, including therapeutic plasma exchange, the immunosuppressive medication rituximab, number of days in the hospital and in the intensive care unit, TTP recurrence rates, and deaths. In both the TITAN and HERCULES trials, the addition of caplacizumab to SOC yielded a higher cost of treatment, and an improvement in quality-adjusted life years, compared to SOC alone. The incremental cost effectiveness ratio for adding caplacizumab to SOC versus SOC alone was $1.5 million dollars at 5 years with a 95% confidence interval of $1.3-1.7 million, far above the current U.S. standard of $195,330.

"We hope to conduct additional studies utilizing longer-term follow-up data once they become available to assess the full impact of caplacizumab on the cost of treating TTP," added Goshua. "In the short term these patients do have increased relapses and more bleeding with the use of caplacizumab in the clinical trials, so we need to be conscious of the fact that we do not know enough in the TTP field about the long-term effects of caplacizumab."