Physicians' Academy for Cardiovascular Education

Antisense oligonucleotide targeting LPA mRNA reduces directly measured Lp(a)-C

Effect of Pelacarsen on Lipoprotein(a) Cholesterol and Corrected Low-Density Lipoprotein Cholesterol

Literature - Yeang C, Karwatowska-Prokopczuk E, Su F, et al. - J Am Coll Cardiol 2022, https://doi.org/10.1016/j.jacc.2021.12.032

Introduction and methods

Background

In previous studies was shown that the antisense oligonucleotide pelacarsen lowers Lp(a) and also oxidized phospholipids (OxPL) on apo(a) and apoB by 70-88%. Somewhat surprisingly, LDL-C levels were reduced up to 26% and total apoB levels up to 16% [1-4].

It is not known whether changes in LDL-C are real or may be caused by laboratory measures of LDL-C (including both true LDL-C plus Lp(a)-cholesterol).

Recently, a novel quantitative, sensitive, high-throughput method has been reported to directly measure Lp(a)-C on isolated Lp(a) holoparticles [5].

In this study, the effect of pelacarsen was assessed on directly measured Lp(a)-C an on corrected LDL-C.

Methods

A phase 2B trial of pelacarsen was previously reported. This was a randomized, double-blind, placebo-controlled, dose-ranging trial of 286 patients with established CVD and Lp(a) levels ≥60 mg/dL. Patients received pelacarsen at 20, 40 or 60 mg every 4 weeks; 20 mg every 2 weeks; or 20 mg every week, or they received placebo for 6 to 12 months.

Direct Lp(a)-C was measured on isolated Lp(a) using LPA4-magnetic beads directed to apo(a). LDL-C was reported as: 1) LDL-C as reported by the clinical laboratory; 2) LDL-Ccorr=laboratory-reported LDL-C minus directly measured Lp(a)-C; and 3) LDL-CcorrDahlén=laboratory LDL-C minus [Lp(a) mass x 0.30] estimated by the Dahlén formula. Primary analysis time point was at week 25/27 (dependent on the dose schedule).

Main results

Baseline levels of LDL-C

Effect of pelacarsen on Lp(a)-C and LDL-C parameters

Correlations between Lp(a)-related variables

Conclusion

The antisense oligonucleotide pelacarsen reduced directly measured Lp(a)-C in a dose-dependent manner, consistent with reduction of Lp(a) molar concentration. Pelacarsen had neutral to modest effects on corrected LDL-C. This analysis further demonstrated that corrected LDL-C is ~13 to 16 mg/dL lower than laboratory-reported LDL-C in patients with elevated Lp(a) levels, and LDL-Ccorr provides an accurate reflection of changes in LDL-C. Moreover, this analysis confirmed that the Dahlén formula overestimates the Lp(a)-C and underestimates LDL-C in subjects with elevated Lp(a) levels.

References

Show references

Find this article online at J Am Coll Cardiol

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