Hemlibra is safe, effective in older patients with other conditions
Data was analyzed from 4 Phase 3 studies that tested therapy in hemophilia A
The efficacy and safety profiles of preventive treatment with Hemlibra (emicizumab-KXWH) are not affected by age or the presence of some simultaneous health conditions, that is, comorbidities, in older people with hemophilia A.
The findings are the result of a post hoc analysis of pooled data from Phase 3 clinical trials that tested Hemlibra in hemophilia A patients. A post hoc analysis is one that’s planned and conducted after a trial has been completed.
“Outcomes in older people with [hemophilia A] with [cardiovascular] risk factors and [HIV/hepatitis C] comorbidities were consistent with those of both younger people with [hemophilia A] and the overall population of people with [hemophilia A]” in these trials, the researchers wrote in “Emicizumab is efficacious in people with hemophilia A with comorbidities aged ≥50 years: analysis of four Phase III trials,” which was published in Research and Practice in Thrombosis and Haemostasis.
Hemlibra is an antibody-based therapy approved for people with hemophilia A, a bleeding disorder caused by the lack or malfunction of the blood clotting protein factor VIII (FVIII). Administered as an injection under the skin, it prevents or reduces the frequency of bleeds by binding to clotting factors IX and X, mimicking the action of FVIII. It can be used in patients with or without inhibitors, or, neutralizing antibodies, against FVIII that can develop with standard FVIII replacement therapies and render them ineffective.
Comparing outcomes in younger, older patients
The adoption of preventive treatment as standard of care for hemophilia A has improved patients’ life expectancy. But “the increasing number of older people with [hemophilia A] presents new challenges, including the management of those with comorbidities, such as [cardiovascular] risk factors, [cardiovascular] disease, and hepatitis C virus (HCV) and HIV infection,” wrote a team of international researchers, including those at Roche and its subsidiary Genentech, which market Hemlibra, who conducted a post hoc analysis of data from four Phase 3 studies that tested Hemlibra in hemophilia A.
The studies included HAVEN 1 (NCT02622321) and STASEY (NCT03191799), which involved hemophilia A patients with FVIII inhibitors; HAVEN 3 (NCT02847637), which enrolled patients without inhibitors; and HAVEN 4 (NCT03020160), which recruited patients regardless of their inhibitor status.
The researchers compared Hemlibra’s effectiveness and safety in hemophilia A patients younger than 50 with older patients who had cardiovascular risk factors or a past or current infection with HIV and/or HCV. A total of 504 patients (median age, 33) with severe hemophilia A were included, with 96 patients making up the older group. Hemlibra was administered for a median of two years.
As expected, comorbidities were more frequent in those 50 and older. Nearly two-thirds of the older patients (72.9%) had at least one cardiovascular risk factor compared with little more than a quarter of the younger patients (26.7%). Also, a greater proportion of older patients had HIV infection (1% vs. 0.7%), HCV infection (50% vs. 19.6%), and HIV and HCV co-infection (22.9% vs. 9.1%).
No significant differences in the mean annualized bleed rate (ABR) for treated bleeds or the number of bleeds per year that required additional treatment were observed between the younger and older groups (1.29 vs. 1.82 bleeds per year).
Similarly, in the older group, there were no significant differences in ABRs for treated bleeds between patients with cardiovascular risk factors, HIV infection, or HCV infection and those without these comorbidities. Older patients with HIV and HCV co-infection had a numerically higher mean ABR relative to younger patients (2.72 vs. 1.29), but the difference wasn’t statistically significant.
The ABR for treated joint and target joint bleeds were similar across younger and older patients with comorbidities.
Also, in the younger group, the mean ABRs for treated bleeds were higher in those with FVIII inhibitors (mean, 1.45 vs. 1.07). In contrast, older patients without FVIII inhibitors had a higher mean ABR relative to those with inhibitors (2.44 vs. 1.22).
For older patients with at least one cardiovascular risk factor, mean ABRs were higher in those without FVIII inhibitors (2.59 vs. 1.15). No notable differences based on inhibitor status were seen for those with HCV or HCV and HIV co-infection.
Rates of adverse events were generally similar between older and younger patients. At least one adverse event was reported in 91.4% in the younger group, 92.7% in the older group, and in up to 95.5% in older patients with comorbidities.
The findings suggest Hemlibra’s effects in older hemophilia A patients with cardiovascular risk factors or HIV/HCV comorbidities are consistent with those of younger patients. Still, the researchers said more studies are needed to assess “the background rates of comorbid conditions in [hemophilia A], as well as the optimal use of hemophilia therapies in this population.”
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