Takhzyro better than Cinryze at preventing HAE attacks: Study
Researchers drew on data from Phase 3 clinical trials in the absence of direct comparison
HAE is marked by recurrent swelling episodes in various parts of the body, including the skin and digestive and respiratory tracts. The attacks can be painful and even life-threatening, especially when they affect the airways.
Some medications help stop the swelling from occurring or make the episodes less severe. Both Takhzyro and Cinryze are marketed by Takeda Pharmaceuticals, which funded the study.
Takhzyro blocks the enzyme kallikrein, whereas Cinryze replenishes C1 esterase inhibitor levels in the blood. Blocking kallikrein and replenishing C1 esterase inhibitor prevent bradykinin, a signaling molecule that makes blood vessels dilate and leak fluid, and cause swelling, from building up.
Comparing Takhzyro, Cinryze indirectly
Because the two medications haven’t been directly compared before, researchers in Germany drew on data from patients who took part in Phase 3 clinical trials to make an indirect comparison. Three of the researchers work at Takeda.
The study, called PATCH, included 27 patients who received 300 mg of Takhzyro injected under the skin every two weeks in HELP (NCT02586805) and 84 others who entered in its open-label extension (NCT02741596).
It also included 120 patients who received 1,000 units of Cinryze into the bloodstream twice a week for three months as part of CHANGE (NCT01005888) and then once or twice a week as they rolled over into an open-label extension (NCT00462709).
Average treatment duration was about the same for Takhzyro and Cinryze (170 vs. 159 days). The proportion of female patients was significantly lower among those treated with Takhzyro (62.2% vs. 75.8%), however.
About three times as many patients taking Takhzyro had received previous long-term prophylaxis (preventive treatment) compared with those treated with Cinryze (90.1% vs. 31.7%).
Those on Takhzyro also had had fewer past attacks, as seen by the lower proportion of patients with two to three attacks in a month (13.5% vs. 25.8%) or with more than three (35.1% vs. 58.3%).
After accounting for these differences, researchers found that the number of attacks among those treated with Takhzyro in a month was about half that among those on Cinryze.
Laryngeal attacks, or those occurring in the neck or throat, were about five times less frequent with Takhzyro. Also, the rate of monthly attacks requiring on-demand treatment in Takhzyro-treated patients was about a third of that with Cinryze.
Being younger than 18, being female, having no chronic diseases, and having fewer than two attacks in a month and no previous laryngeal attacks were linked to fewer swelling episodes.
“The PATCH study contributes and enhances current knowledge in the evaluation of [long-term prophylaxis] for HAE,” the researchers wrote. While both medications “improved the HAE “disease burden,” the indirect comparison showed Takhzyro may be better than Cinryze at preventing attacks, including those affecting the breathing passages.