Indirect Comparison of Lanadelumab and Intravenous C1-INH Using Data from the HELP and CHANGE Studies: Bayesian and Frequentist Analyses

Indirect treatment comparison of oral sebetralstat and intravenous recombinant human C1 esterase inhibitor for on-demand treatment of hereditary angioedema attacks

BACKGROUND

The goal of on-demand treatment for hereditary angioedema attacks is to halt attack progression to minimize morbidity and mortality. Four on-demand treatments have been approved thus far (ecallantide, icatibant, recombinant human C1 esterase inhibitor [rhC1INH], and plasma-derived C1INH). Results from the sebetralstat phase 3 KONFIDENT trial (NCT05259917) have been reported. To put these results into context without head-to-head trials, an indirect treatment comparison (ITC) was conducted to facilitate comparisons of efficacy and safety across treatment options.

METHODS

Based on a systematic literature review and feasibility assessment, only the pivotal trial for intravenous rhC1INH (NCT01188564) reported necessary data for a comparable primary efficacy endpoint (time to beginning of symptom relief) to enable an ITC with oral sebetralstat. Bayesian fixed-effects network meta-analyses models were conducted to indirectly compare the efficacy and safety outcomes of sebetralstat and rhC1INH (NCT01188564, NCT00225147, NCT00262301). A matching-adjusted indirect comparison (MAIC) of efficacy was performed, adjusting for baseline attack severity and demographic characteristics.

RESULTS

The fixed-effects model found no significant differences in time to beginning of symptom relief between sebetralstat 300 mg and rhC1INH 50 IU/kg (hazard ratio [95% credible interval], 0.96 [0.42-2.15] to 1.19 [0.58-2.45]). After adjusting for baseline attack severity, the MAIC showed numerically favorable results with sebetralstat compared with rhC1INH, regardless of whether baseline demographics were matched. The fixed-effects model found no significant differences in treatment-related treatment-emergent adverse events. All sensitivity analyses returned consistent results.

CONCLUSIONS

This ITC found no significant differences in time to beginning of symptom relief and overall treatment-related treatment-emergent adverse events between sebetralstat and rhC1INH.

Indirect treatment comparison of lanadelumab and a C1-esterase inhibitor in pediatric patients with hereditary angioedema

Aim: To compare the efficacy and safety of lanadelumab versus other approved long-term prophylaxis (LTP) treatments in patients with pediatric hereditary angioedema (HAE) aged <12 years. Materials & methods: A systematic literature review was conducted to identify studies of LTP in patients with HAE aged <12 years. Two studies met the inclusion criteria in an indirect treatment comparison of efficacy and safety data in pediatric HAE patients. These were for lanadelumab (SPRING, NCT04070326) and intravenous-C1-esterase inhibitor (C1-INH[IV], NCT02052141). A propensity score analysis used individual patient-level data from both studies in a logistic regression model to estimate inverse probability weights. To avoid convergence issues and an underpowered analysis due to the small sample size (n = 29), the base case was defined as Poisson regression analyses on monthly attack rate adjusting for one covariate (baseline attack rate). Model selection among unadjusted, adjusted and weighted regression models was conducted through the Akaike and Bayesian Information Criteria. Results: Lanadelumab 150 mg every 2 weeks (Q2W) reduced the monthly HAE attack rate by 82.1% versus C1-INH(IV) 1000 IU twice weekly (every 3-4 days [BIW]; rate ratio [RR], 0.1792 [95% CI: 0.0296-1.0853]) and by 88.9% versus C1-INH(IV) 500 IU BIW (RR: 0.1107 [95% CI: 0.0234-0.5239]). Treatment with lanadelumab Q2W reduced the risk of total adverse events by 56.2% versus C1-INH(IV) 1000 IU BIW (RR:0.4377 [95% CI: 0.1536-1.2469]) and by 66.0% versus C1-INH(IV) 500 IU BIW (RR: 0.3401 [95% CI: 0.1234-0.9371]). Conclusion: This exploratory analysis suggested a trend toward greater efficacy and fewer adverse events with lanadelumab 150 mg Q2W compared with C1-INH(IV) BIW 1000 IU and 500 IU in pediatric patients with HAE. Future studies could potentially assess larger samples over longer periods of time for the long-term preventative efficacy, safety and tolerability of lanadelumab and C1-INH(IV).

Patient-level indirect treatment comparison of lanadelumab versus pdC1-INH i.v. in hereditary angioedema patients: PATCH study

BACKGROUND

Hereditary angioedema (HAE) is an autosomal dominant inherited disease in which patients suffer from local attacks primarily affecting skin and gastrointestinal tract, and sometimes even the upper respiratory tract leading to asphyxiation. Since head-to-head trials between authorized treatments are lacking, this study compares efficacy and safety of lanadelumab and intravenous plasma-derived C1-esterase inhibitor (pdC1-INH i.v.) in HAE patients on long-term prophylaxis by means of an indirect treatment comparison.

METHODS

Efficacy and safety of lanadelumab against pdC1-INH i.v. were analyzed in a fully prespecified indirect comparison based on individual patient data (n = 231) from the HELP and CHANGE clinical trials. Primary and secondary efficacy endpoints were compared using a generalized linear model for count data. Confounding variables were identified a priori via systematic literature research and validated by clinical experts. Adjustment of confounders was implemented using a conditional regression model.

RESULTS

Lanadelumab showed a statistically significant improvement in reduction of HAE attack rates compared to pdC1-INH i.v. across multiple endpoints: Monthly attack rate of patients treated with lanadelumab was less than half compared to pdC1-INH i.v. (Rate ratio: 0.486; 95% CI: 0.253, 0.932). Monthly rate of laryngeal attacks was found to be five times lower for lanadelumab (Rate ratio: 0.2; 95% CI: 0.044, 0.915) and monthly rate of acute treated HAE attacks among lanadelumab patients was about one third of the attack rate of pdC1-INH i.v. patients (Rate ratio: 0.366; 95% CI: 0.185, 0.727).

CONCLUSION

This study contributes to current knowledge in the treatment of HAE by indicating a statistically significant reduction of HAE attacks under lanadelumab compared to pdC1-INH i.v.

Network meta-analysis for indirect comparison of lanadelumab and berotralstat for the treatment of hereditary angioedema

Aim: With no head-to-head studies comparing the effectiveness of lanadelumab and berotralstat for prevention of hereditary angioedema (HAE) attacks, this network meta-analysis (NMA) aimed to indirectly compare the effectiveness of these treatments. Materials & methods: The NMA, using the published data from Phase III trials, was performed using a frequentist weighted regression-based approach following Rücker et al. Efficacy outcomes of interest were HAE attack rate per 28 days and ≥90% reduction in monthly HAE attacks. Results & conclusion: In this NMA, lanadelumab 300 mg administered every 2 weeks or every 4 weeks was associated with statistically significantly higher effectiveness versus berotralstat 150 mg once daily (q.d.) or 110 mg q.d. for both efficacy outcomes assessed.

Impact of lanadelumab in hereditary angioedema: a case series of 12 patients in Canada

BACKGROUND

Hereditary angioedema (HAE) is a rare autosomal dominant disease resulting in recurring episodes of swelling, leading to considerable patient morbidity and mortality. Lanadelumab is a plasma kallikrein inhibitor that is approved as 1st line therapy in Canada for long term prophylaxis of HAE attacks.

OBJECTIVE

To describe our clinical findings from a case series of adult patients with HAE type 1/2 who have been initiated on lanadelumab.

METHODS

A chart review of HAE type 1/2 patients at three academic centers in Canada was undertaken with demographic and clinical data extracted. Patients were included if they had been receiving lanadelumab for at least 6 months. Patients with other causes of angioedema were excluded.

RESULTS

12 patients meeting enrollment criteria were identified. Compared to pre-lanadelumab, patients had mean reductions of 72% and 62% in attack rate and treated attack rate respectively. 3 patients reported complete remission from attacks after starting lanadelumab. Most patients had significant improvements in HAE impact on social outings.

CONCLUSION

Our case series findings support the 2019 International/Canadian HAE guideline that lanadelumab is an effective therapy for long term prophylaxis. In our patient population, initiation of lanadelumab improved disease control, minimized the burden of treatment and improved HAE impact on social outings.