Christopher Anzalone
Practice takePresident and CEO, Arrowhead PharmaceuticalsPlozasiran could fundamentally change how severe hypertriglyceridemia is treated
Original post ↗View all ESC 2026 trials
SHASTA-3/4LipidsOpen Access
Plozasiran in patients with severe hypertriglyceridaemia: 12-month results
What happened
Plozasiran cuts triglycerides by ~80% versus placebo in severe hypertriglyceridemia.
- n=757
Does this change practice?
Where experts agree
Arrowhead's leadership and the presenting clinician all emphasize that plozasiran's pancreatitis reduction, not just triglyceride lowering, is the clinically important finding, particularly in higher-risk patients with prior episodes.
What this trial adds
Experts see plozasiran's roughly 80% triglyceride reduction and 78% cut in acute pancreatitis events as a potentially practice-changing advance for severe hypertriglyceridaemia, though questions remain about long-term cardiovascular outcomes and the higher rate of glycemic-control events.
Published field read
The reaction to SHASTA-3/4 is broadly positive, with clinicians and the drug's developers highlighting not just the depth of triglyceride lowering but the clinically meaningful reduction in pancreatitis, especially in patients with prior episodes. No expert voice has pushed back on the results, though independent clinical commentary is limited. The live question is whether these surrogate and pancreatitis findings will translate into cardiovascular event reduction and regulatory approval, and whether the glycemic safety signal warrants closer scrutiny.
Still open
Questions raised in published commentaryWhether the triglyceride and pancreatitis benefits will translate into reduced cardiovascular events over longer follow-up remains untested.
The higher rate of glycemic-control events with plozasiran, flagged in at least one summary, has not yet been discussed in depth by independent clinicians.
It is also unclear how quickly guideline bodies or regulators will act on these data.
Context from published commentary. Source summaries are not a new guideline recommendation.
Who says what
Martha Gulati
Results readoutCardiologistPowerful triglyceride lowering paired with fewer pancreatitis events makes this a standout result
X post ↗
Flagged SHASTA-3/4 as a Hot Line session to watch at ESC
X post ↗Show 4 more perspectivesShow fewer perspectives
James Hamilton
Results readoutChief Medical Officer, Arrowhead PharmaceuticalsDeep, durable triglyceride lowering with a favorable safety profile across a heterogeneous population
Original post ↗
Summarized the one-year result as a substantial 80% triglyceride reduction versus 27% with placebo.
X post ↗Biotech Explained
@explainbiotech“JUST ARRIVED — $ARWR Detailed Phase 3 SHASTA-3/4 data for plozasiran are now out at ESC. The simple story: Plozasiran lowers ApoC-III → triglycerides fall ~80%. But the important part is clinical: Acute pancreatitis events were reduced by 78% vs placebo. At 12 months, >90%”
X ↗Mohammed Al-Qadami
@mohamme76294268“SHASTA-3/4: In 757 patients with severe hypertriglyceridaemia, quarterly plozasiran reduced triglycerides by ~80% and acute pancreatitis events (RR 0.22), with no new safety signal.”
X ↗What should the author answer first?
Upvote a question you would like answered, or open it to join the discussion.
Full evidence
Why the trial, key points, tables, limitations, PICO, abstract, media & sources
Full evidence
Why the trial, key points, tables, limitations, PICO, abstract, media & sources
Why the trial?
Severe hypertriglyceridaemia drives acute pancreatitis and existing therapies lower triglycerides only modestly. SHASTA-3 and SHASTA-4 asked whether plozasiran, an RNA interference agent targeting APOC3, produces deep and durable triglyceride reduction over 12 months.
Does plozasiran reduce triglyceride levels in patients with severe hypertriglyceridaemia?
View moreView less
Key Points
- Evaluate the efficacy and safety of quarterly plozasiran injections over 12 months in patients with severe hypertriglyceridaemia.
- SHASTA-3 and SHASTA-4 were double-blind trials conducted across 24 countries enrolling 757 patients (mean age 53 years; 22% women) with triglyceride levels ≥500 mg/dL.
- Patients were randomized 2:1 to receive four quarterly subcutaneous injections of plozasiran 25 mg or placebo over one year.
- At month 12, median triglycerides fell by 79% in SHASTA-3 and 81% in SHASTA-4 in the plozasiran group versus approximately 27% with placebo in each trial.
- Cumulative acute pancreatitis events decreased by 78% overall with plozasiran versus placebo, and by 100% in patients with baseline triglycerides >880 mg/dL and prior pancreatitis, with no new safety signals.
Evidence details
What drove the result?
| Outcome | Plozasiran | Placebo |
|---|---|---|
| Median triglyceride change at month 12 — SHASTA-3 | −79% | ~−27% |
| Primary · p<0.0001 per trial record (not stated in abstract) | ||
| Median triglyceride change at month 12 — SHASTA-4 | −81% | ~−27% |
| Primary · p<0.0001 per trial record (not stated in abstract) | ||
| Cumulative acute pancreatitis events (pooled) | ||
| Secondary · 78% reduction vs placebo; 100% reduction in the TG>880 mg/dL + prior pancreatitis subset; per-arm counts not reported | ||
Limitations & tradeoffs
Design limitations
The primary endpoint is a lipid surrogate, not a clinical outcome, and results come from a conference press release without journal publication.
Statistical certainty
Pancreatitis results are pooled across the two trials without per-arm counts or confidence intervals, and safety is described only as 'no new safety signals' with no numeric data.
Structured PICO
Does plozasiran reduce triglyceride levels in patients with severe hypertriglyceridaemia?
P
Population
757 patients (mean age 53 years; 22% women) with triglyceride levels of 500 mg/dL or greater, followed for one year.
I
Intervention
Plozasiran 25 mg via four quarterly subcutaneous injections over one year
C
Comparator
Placebo via four quarterly subcutaneous injections over one year
O
Outcome
Median triglycerides at month 12surrogate
Plozasiran significantly reduces triglyceride levels and the risk of acute pancreatitis in patients with severe hypertriglyceridemia.
Discussion
No takes yet. Share an insight, caveat, or question.
Expert reaction
What experts said about SHASTA-3/4
ESC Congress 2026
3 experts quoted, 2 with a clear stance so far. We show the split once 3 have one.
Expert labels are toward SHASTA-3/4's result, from named public quotes (n=2). As of Aug 31, 2026.
Where experts stand
Experts see plozasiran's roughly 80% triglyceride reduction and 78% cut in acute pancreatitis events as a potentially practice-changing advance for severe hypertriglyceridaemia, though questions remain about long-term cardiovascular outcomes and the higher rate of glycemic-control events.
The reaction to SHASTA-3/4 is broadly positive, with clinicians and the drug's developers highlighting not just the depth of triglyceride lowering but the clinically meaningful reduction in pancreatitis, especially in patients with prior episodes. No expert voice has pushed back on the results, though independent clinical commentary is limited. The live question is whether these surrogate and pancreatitis findings will translate into cardiovascular event reduction and regulatory approval, and whether the glycemic safety signal warrants closer scrutiny.
Agreement
Arrowhead's leadership and the presenting clinician all emphasize that plozasiran's pancreatitis reduction, not just triglyceride lowering, is the clinically important finding, particularly in higher-risk patients with prior episodes.
3 clinicians say this directly
What they’re arguing about
supportiveneutralcautiouscritical
Counts are expert takes we classified by axis. Tap a row to see the takes behind its count.
Still unclear
Whether the triglyceride and pancreatitis benefits will translate into reduced cardiovascular events over longer follow-up remains untested. The higher rate of glycemic-control events with plozasiran, flagged in at least one summary, has not yet been discussed in depth by independent clinicians. It is also unclear how quickly guideline bodies or regulators will act on these data.
Key expert perspectives
MGMartha GulatiCardiologistResults readoutAug 31
Powerful triglyceride lowering paired with fewer pancreatitis events makes this a standout result
Gulati highlighted the 79% and 81% triglyceride reductions versus placebo and the 78% drop in acute pancreatitis events, calling the combination "powerful." She noted that over 90% of treated patients achieved triglycerides below 500 mg/dL on plozasiran, while flagging the low enrollment of women at 22%.
CAChristopher AnzalonePresident and CEO, Arrowhead PharmaceuticalsPractice takeAug 31
Plozasiran could fundamentally change how severe hypertriglyceridemia is treated
Anzalone described the pancreatitis reduction as potentially the most important finding for patients and physicians, especially in those with prior episodes. He positioned plozasiran as best in class for safety, efficacy, and convenience with quarterly dosing, saying the broad study population closely resembles today's diverse patient landscape.
Flagged SHASTA-3/4 as a Hot Line session to watch at ESC
Țica previewed the Hot Line 9 session listing SHASTA-3/4 alongside trials on blood pressure control and salt substitution in CKD.
Distilled from their postX post
Implication
Supports quarterly plozasiran to lower pancreatitis risk in severe hypertriglyceridemia; extends prior data to 12-month outcomes in two phase 3 trials.
Abstract
SHASTA-3 and SHASTA-4 were double-blind trials conducted across 24 countries in patients with triglyceride levels of 500 mg/dL or greater. In total 757 patients (mean age 53 years; 22% women) were randomised 2:1 to four quarterly subcutaneous injections of plozasiran 25 mg or placebo over one year. For the primary endpoint, median triglycerides at month 12 fell 79% in SHASTA-3 and 81% in SHASTA-4 versus approximately 27% with placebo in each trial. Across the trial populations cumulative acute pancreatitis events were reduced by 78% with plozasiran versus placebo; in the subset with triglycerides above 880 mg/dL and a prior history of acute pancreatitis, a 100% reduction in acute pancreatitis events was observed. No new safety signals were identified. Source: ESC Congress 2026 press release, 30 August 2026.
Coverage & sources
Journal, society, and media accounts. Useful signal, not independent expert judgment.
Cite This Study
Gerald Watts (2026) conducted an RCT in Severe hypertriglyceridaemia (n=757). Plozasiran vs. Placebo was evaluated on Median triglycerides at month 12. Plozasiran reduced median triglycerides at 12 months by 79% to 81% versus 27% with placebo, and reduced cumulative acute pancreatitis events by 78%.