An additional 41 percent in the ACE-LY-004 trial saw their tumors shrink, and the treatment stabilized the disease of 9 percent — for a disease control rate of 90 percent. All of the patients’ cancer had returned after previous treatment.
The findings prompted the U.S. Food and Drug Administration to grant accelerated approval of Calquence as a treatment for relapsed or refractory mantle cell lymphoma in October 2017.
Researchers presented the results at last year’s 59th American Society of Hematology Annual Meeting. The presentation was titled “Efficacy and Safety of Acalabrutinib Monotherapy in Patients with Relapsed/Refractory Mantle Cell Lymphoma in the Phase 2 ACE-LY-004 Study.”
The trial (NCT02213926) covered 124 patients from nine countries. Its main goal was to determine the proportion of patients who achieved a partial or complete response to the therapy. Scientists consider this yardstick, known as overall response rate, a direct measure of a drug’s anti-tumor activity.
Two of the additional trial objectives were seeing how long it took patients’ disease to progress and what their overall survival rate was. Other objectives included seeing how an independent trial review board assessed overall response rate and evaluating the therapy’s safety.
Researchers also assessed its pharmacokinetics, or how the body metabolizes and clears it, and pharmacodynamics, or how it affects the body.
Participants received 100 mg of oral Calquence, a selective BTK inhibitor, twice a day until their disease progressed or they experienced unacceptable toxicity.
After a median follow-up of 15.2 months, 81 percent of patients had responded to the treatment, and 40 percent no longer had signs of cancer. In addition, 9 percent had achieved a stable disease, meaning that 90 percent of patients had some sort of benefit.
It took patients an average of 1.9 months to respond to the therapy. After one year, 72 percent were still responding.
Progression-free survival — the time from beginning of treatment to disease progression or death from any cause — and overall survival — the time until death from any cause — had not been reached at the time of follow-up. This meant that more than half of patients were still alive and progression-free.
At one year, the progression-free survival rate was 67 percent and the overall survival rate 87 percent.
The therapy showed a favorable safety profile, with a low frequency and severity of adverse events, leading to few treatment discontinuations. The most common non-blood-related adverse reactions included headache, diarrhea, fatigue, and muscle pain.
“The results presented for the first time to the medical community highlight the potential of Calquence as a treatment for people with relapsed or refractory mantle cell lymphoma, a life-threatening form of blood cancer. These data reinforce the important progress of our clinical development program as well as our commitment to advancing the treatment of patients with blood cancers,” Sean Bohen, executive vice president of Global Medicines Development and chief medical officer of AstraZeneca, said in a press release.
“Most people living with mantle cell lymphoma will unfortunately relapse, and new treatment options are greatly needed. As shown by the consistent overall response rates observed in this trial across several pre-specified subgroups, acalabrutinib is a welcome new treatment option for certain patients with this aggressive blood cancer,” added Dr. Michael L. Wang, the study’s principal investigator. He is a professor in the Department of Lymphoma/Myeloma at the University of Texas MD Anderson Cancer Center.