researchers report.
In a separate phase 2 study, olpasiran (Amgen), which is given by injection, lowered Lp(a) levels for nearly 1 year after the last dose, also without safety concerns, in a phase 2 trial extension.
Researchers presented these findings in two late breaking science sessions at the recent annual congress of the European Society of Cardiology. The muvalaplin trial was also simultaneously published online as a preliminary communication in JAMA.
Phase 1 trial of muvalaplin
Epidemiologic and genetic evidence suggests that Lp(a) has a causal role in cardiovascular disease (CVD) events, Stephen J. Nicholls, MBBS, PhD, and colleagues wrote.
In initial studies, Lp(a) was reduced by approximately 80% with an antisense oligonucleotide (pelacarsen, Ionis) and by up to 98% with RNA interference (olpasiran) – both injectable therapies.
Muvalaplin is a small molecule that disrupts the binding of apolipoprotein(a) to apo B100 that forms Lp(a), said Dr. Nicholls, from Monash University and Victoria Heart Institute, both in Melbourne.
In this first-in-human, phase 1 trial in 114 healthy individuals, Lp(a) levels were reduced up to 65% following daily administration of 100-800 mg of muvalaplin for 14 days, without safety or tolerability concerns or significant effects on plasminogen, a homologous protein, he said in an interview.
Approximately 20% of the population have high LP(a) levels, Dr. Nicholls noted.
“We saw in the PCSK9 [proprotein convertase subtilisin/kexin type 9] inhibitor trials that Lp(a) lowering is associated with benefit, but those agents substantially lower LDL cholesterol,” he said. “Now, here for the first time we have an oral agent” that lowers Lp(a) levels. However, “we will still need to determine if this leads to a reduction in cardiovascular risk,” in longer and larger trials.
The researchers randomly assigned healthy adults aged 18-69 with a BMI of 30 kg/m2 or less, into two groups.
The 55 participants in the single ascending dose group were randomly assigned to receive muvalaplin (1 mg, 10 mg, 30 mg, 100 mg, 200 mg, 400 mg, or 800 mg) or matching placebo daily for 14 days. They had a mean age of 29 years; 64% were female and 91% were White. Their median Lp(a) level was 10.3 mg/dL.
The 59 participants in the multiple ascending dose group, who were required to have Lp(a) of at least 30 mg/dL, were randomly assigned to receive muvalaplin (30 mg, 100 mg, 300 mg, 500 mg, or 800 mg) or placebo daily for 14 days. They had a mean age of 32; 58% were female and 80% were White. Their median Lp(a) level was 58.4 mg/dL.
The maximum placebo-adjusted Lp(a) reduction was 63% to 65%, which occurred on days 14 and 15, in participants who received doses of at least 100 mg.
The levels returned to baseline by day 29 for the 30-mg dose, day 43 for the 100-mg dose, and day 64 for the 300- to 800-mg doses.
There were no deaths or serious adverse events. Treatment-associated adverse events were reported by 62% in the single ascending dose group and by 80% in the multiple ascending dose group; these were mild and transient and included headache, fatigue, and vomiting.
Muvalaplin had no significant effects on LDL cholesterol, HDL cholesterol, or total cholesterol or apo B100, and did not significantly affect plasminogen levels or activity.
The team is currently conducting the phase 2 KRAKEN trial. They plan to enroll 233 patients aged 40 and older with elevated Lp(a) levels (≥ 175 nmol/L) and high risk for cardiovascular events. The primary outcome is change in Lp(a) levels at 12 weeks, and the estimated primary trial completion is this coming January.