Impact of PCSK9 inhibitors on plasma lipoprotein(a) concentrations with or without a background of niacin therapy.

Lipoprotein(a) [Lp(a)] is an atherogenic lipoprotein associated with atherosclerotic cardiovascular disease. Niacin and proprotein convertase subtilisin/kexin type 9 inhibitors (PCSK9i) both lower Lp(a). The objective of the study was to determine if addition of PCSK9i to background niacin therapy further lowers Lp(a). This study is a retrospective analysis of patients who met the following inclusion criteria: initiated PCSK9i therapy, had Lp(a) measurements before and after initiation of PCSK9i, and for the combination therapy group, PCSK9i was added on top of baseline niacin monotherapy. Of the 150 patients included in this study, 136 were on monotherapy (PCSK9i) and 14 were on combination therapy (niacin + PCSK9i). Lp(a) values were assessed in both groups before and after the addition of PCSK9i. Median percent and absolute Lp(a) reductions in the niacin + PCSK9i combination therapy group were -15.3% (interquartile range [IQR] -31.8, -1) and -9 mg/dL (IQR -37.2, -0.5), respectively, from a baseline Lp(a) of 95 mg/dL (IQR 20.5, 171). These reductions were statistically significant or nearly so (P = .04 and P = .05, respectively). Median percent and absolute Lp(a) reductions in the PCSK9i monotherapy group were -17.3% (IQR -34.4, 0) and -6 mg/dL (IQR -16, 0), respectively, from a baseline Lp(a) of 39.5 mg/dL (IQR 15, 117.5). There was no difference in median percent and absolute change in Lp(a) between monotherapy and combination therapy groups (P = .84 and P = .54, respectively). Our study demonstrates that the addition of PCSK9i to background of niacin therapy is associated with ∼15% reduction in Lp(a) beyond that achieved with background niacin monotherapy.

Warden BA ，Minnier J ，Watts GF ，Fazio S ，Shapiro MD ... -  《-》

Discordant response of low-density lipoprotein cholesterol and lipoprotein(a) levels to monoclonal antibodies targeting proprotein convertase subtilisin/kexin type 9.

Clinical trials testing proprotein convertase subtilisin/kexin type 9 inhibitors (PCSK9i) have demonstrated an unanticipated but significant lipoprotein (a) (Lp(a))-lowering effect, on the order of 25% to 30%. Although the 50% to 60% reduction in low-density lipoprotein (LDL)-cholesterol (LDL-C) achieved by PCSK9i is mediated through its effect on LDL receptor (LDLR) preservation, the mechanism for Lp(a) lowering is unknown. We sought to characterize the degree of concordance between LDL-C and Lp(a) lowering because of PCSK9i in a standard of care patient cohort. Participants were selected from our Center for Preventive Cardiology, an outpatient referral center in a tertiary academic medical center. Subjects were included in this study if they had (1) at least 1 measurement of LDL-C and Lp(a) before and after initiation of the PCSK9i; (2) baseline Lp(a) > 10 mg/dL; and (3) continued adherence to PCSK9i therapy. They were excluded if (1) they were undergoing LDL apheresis; (2) pre- or post-PCSK9i LDL-C or Lp(a) laboratory values were censored; or (3) subjects discontinued other lipid-modifying therapies. In total, 103 subjects were identified as taking a PCSK9i and 26 met all inclusion and exclusion criteria. Concordant response to therapy was defined as an LDL-C reduction >35% and an Lp(a) reduction >10%. The cohort consisted of 26 subjects (15 females, 11 males, mean age 63 ± 12 years). Baseline mean LDL-C and median Lp(a) levels were 167.4 ± 72 mg/dL and 81 mg/dL (interquartile range 38-136 mg/dL), respectively. The average percent reductions in LDL-C and Lp(a) were 52.8% (47.0-58.6) and 20.2% (12.2-28.1). The correlation between %LDL and %Lp(a) reduction was moderate, with a Spearman's correlation of 0.56 (P < .01). All subjects except for 1 had a protocol-appropriate LDL-C response to therapy. However, only 16 of the 26 (62%; 95% confidence interval 41%-82%) subjects had a protocol-concordant Lp(a) response. Although some subjects demonstrated negligible Lp(a) reduction associated with PCSK9i, there were some whose Lp(a) decreased as much as 60%. In this standard-of-care setting, we demonstrate moderate correlation but large discordance (∼40%) in these 2 lipid fractions in response to PCSK9i. The results suggest that pathways beyond the LDLR are responsible for Lp(a) lowering and indicate that PCSK9i have the potential to significantly lower Lp(a) in select patients, although confirmation in larger multicenter studies is required.

Edmiston JB ，Brooks N ，Tavori H ，Minnier J ，Duell B ，Purnell JQ ，Kaufman T ，Wojcik C ，Voros S ，Fazio S ，Shapiro MD ... -  《-》

Experience with proprotein convertase subtilisin/kexine type 9 inhibitors (PCSK9i) in patients undergoing lipoprotein apheresis.

We analyzed efficacy and safety of PCSK9i in patients undergoing lipoprotein apheresis (LA) and in patients treated at our outpatient department for metabolic disorders. The medical records of 40 LA patients, taking PCSK9i were reviewed with respect to LDL-cholesterol (LDL-C) and lipoprotein(a) (Lp(a)) lowering as well as occurrence of adverse events. Furthermore, we analyzed the data of 152 patients of our outpatient department, undergoing PCSK9i therapy. Mean pre-apheresis LDL-C value was reduced by PCSK9i from 3.71 ± 1.19 to 1.78 ± 0.84 mmol/l (53 ± 12%). The relative lowering of the pre-apheresis Lp(a) was 20 ± 12% (from 191 ± 63.5 to 152 ± 51.9 nmol/l). 25% of LA patients could stop LA after reaching LDL-C target after initiation of PCSK9i. 75% of the patients are continuing the regular LA therapy, showing an insufficient LDL-C lowering following PCSK9i injections or/and additionally elevated Lp(a) or/and adverse effects of PCSK9i, leading to the discontinuation of injections. The number of LA patients has grown from 112 in 2016 to 128 nowadays due to an increasing percentage of patients with elevated Lp(a) (79% and 89% respectively). The mean reduction rate of LDL-C under PCSK9i therapy in outpatients was 53.03%. In 34% of patients the target value could not be reached. 43% of persons suffered from adverse effects. 3/4 of LA patients could not stop extracorporeal treatment after PCSK9i administration. In hypercholesterolemic patients with coexisting elevated Lp(a) and progressive cardiovascular disease the combination of LA and PCSK9i could be beneficial. The total patients' number in LA units increases due to persons with Lp(a)-hyperlipoproteinemia.

Tselmin S ，Julius U ，Weinert N ，Bornstein SR ，Schatz U ... -  《-》

Use of Low-Density Lipoprotein-Lowering Therapies Before and After PCSK9 Inhibitor Initiation.

Rymer JA ，Mues KE ，Monda KL ，Bratton EW ，Wirtz HS ，Okerson T ，Overman RA ，Brookhart MA ，Muntner P ，Wang TY ... -  《Journal of the American Heart Association》

Real-World Efficacy of Proprotein Convertase Subtilisin/Kexin Type 9 Inhibitors (PCSK9i) in Heterozygous Familial Hypercholesterolemia Patients Referred for Lipoprotein Apheresis.

Matta A ，Bongard V ，Bouisset F ，Taraszkiewicz D ，Rabès JP ，Ferrières J ... -  《MEDICAL SCIENCE MONITOR》