Arrowhead Pharmaceuticals (ARWR) Q4 2026 earnings review
Arrowhead's prescriptions and pipeline advance, but partner revenue drops
Arrowhead Pharmaceuticals — a developer of gene-silencing medicines — accelerated its first drug launch and cleared key clinical hurdles while its partner revenue shrank. Chief executive Christopher Anzalone said the biotech group is turning scientific promise into patient outcomes as weekly prescriptions for its triglyceride drug REDEMPLO roughly doubled to between 50 and 60. By our math, fourth-quarter revenue dropped to $38 million as past partner milestones did not repeat, and operating costs excluding a $215 million regulatory voucher rose to $259 million.
| Q4 revenue (by our math) | $37.8M −85% from a year ago on lower partner milestones |
|---|---|
| REDEMPLO weekly prescriptions | 50–60 up from 20–30 per week last quarter |
| Operating expenses, excluding voucher | $943M +29% for the full year |
| US sHTG launch plan | Unchanged Q2 2027 target via FDA fast-track program |
⚖️ Verdict: 🟢 Bullish
The story got better because the US regulator admitted REDEMPLO's application for severe hypertriglyceridemia into an expedited review program, keeping the second-quarter 2027 launch plan on track while saving the $215 million voucher for a future drug. Early human data also proved Arrowhead can silence genes in the brain with an injection under the skin, and a loan refinancing cut interest costs and removed a $68 million payoff penalty. One caution: the company still hides REDEMPLO dollar sales inside total revenue while sales overhead climbs.
The question now is whether rising prescriptions and the upcoming label expansion can build commercial revenue fast enough to offset draining partner balances and higher sales costs. Either the annual filing reveals strong net pricing per patient, or heavy discounting keeps drug revenue small beside a quarterly burn near $160 million. The product revenue footnote in the upcoming Form 10-K report will tell.
🐂 Bull Case
FDA Fast-Tracks the Larger Triglyceride Market
Arrowhead sells REDEMPLO (plozasiran), an injection that silences a liver gene to lower blood fats called triglycerides, for a rare genetic condition. The bigger prize is severe hypertriglyceridemia (sHTG), a much more common condition that causes painful pancreas inflammation. Arrowhead submitted its application for sHTG ahead of its year-end schedule and won entry into the US regulator's Split Real Time Application Review (STAR) pilot program.
- Pancreatitis attacks in Phase 3 trials: down 78% against placebo across all sHTG patients, and down 91% in patients with a prior attack
- Median triglyceride levels: cut by 79% and 81% in the two Phase 3 studies
- Review clock: shortened from a standard 10 months to 6 months or less, targeting a US launch in the second quarter of 2027
- Priority Review Voucher: kept in reserve after costing $215 million this quarter, because the STAR program does not require one
Entry into STAR matters because the regulator only admits drugs that may show "substantial improvement on a clinically relevant endpoint(s) over available therapies". That decision validates the pancreatitis data before the review even finishes, and lets Arrowhead save its $215 million voucher to speed up a future drug.
What to watch: the FDA approval decision and label wording in the second quarter of 2027. An approval that includes the pancreatitis reduction data in the label would give Arrowhead an edge over Ionis's rival drug.
REDEMPLO Prescriptions Break Above the Initial Plateau
REDEMPLO is approved for familial chylomicronemia syndrome (FCS), a rare disease where body fat levels reach dangerous heights. During the spring, new prescriptions had plateaued at 20 to 30 a week, raising doubts about demand. In the fourth quarter, new-to-brand prescriptions rose 63% from the previous quarter and weekly volume reached 50 to 60.
Doctors and insurers are adopting the treatment faster. More than 640 doctors had prescribed the drug by September, rising past 860 by mid-November, and US health plans now cover 160 million people. Europe is opening too: doctors are prescribing the drug in Germany, and British authorities recommended government funding. The pickup eases the concern that the initial launch was stalling.
What to watch: the exact dollar figure for REDEMPLO sales in the upcoming annual Form 10-K filing. A sequential rise above the third quarter's $2.4 million pace will confirm that higher prescriptions are turning into paid shipments.
Early Human Trials Validate Brain and Dual-Gene Drugs
Until now, RNA interference (RNAi) medicines — drugs that turn off disease-causing genes — have mostly worked in the liver, and brain treatments needed spinal injections. Arrowhead tested two new approaches in early human trials this quarter: an injection under the skin for Alzheimer's disease (ARO-MAPT) and a single drug for heart disease (ARO-DIMER-PA) built to "target and silence two genes simultaneously in one molecule".
Both trials worked. ARO-MAPT cut tau — the toxic brain protein tied to Alzheimer's — by up to 73% on average in spinal fluid, proving the platform can "deliver siRNA across the blood-brain barrier and achieve substantial target gene knockdown in the brain". ARO-DIMER-PA lowered both bad cholesterol (up to 65%) and triglycerides (up to 78%).
What to watch: larger patient trial designs and potential pharmaceutical partner deals for ARO-MAPT in 2027. An upfront licensing payment from a major drugmaker would turn this brain delivery breakthrough into non-dilutive cash.
New Loan Cuts Interest Costs and Saves $68 Million
Arrowhead carried an expensive loan from Sixth Street that charged 15% annual interest, required at least double the borrowed money back on payoff, and took a cut of partner milestones and drug sales. After the quarter ended, the drugmaker refinanced that debt with a new $400 million loan maturing in November 2031.
The new facility cuts the interest rate to the benchmark SOFR rate plus 5.50%, knocks $68 million off the payoff bill from the old loan, and "eliminates these required prepayments or sweeps". That resolves a persistent balance-sheet drag over the next five years and lets Arrowhead keep all cash from future partnerships and REDEMPLO sales.
What to watch: quarterly interest expense in the transition report for the final three months of 2026. The lower rate and retired payoff premium should immediately reduce financing costs.
🐻 Bear Case
Partner Revenue Drains While Drug Sales Stay Hidden
"Arrowhead has fundamentally changed over the past 12 months," chief executive Christopher Anzalone said, calling it a business "beginning to translate promise into real patient outcomes". Yet the income statement still hides how much money its only approved drug makes. Arrowhead groups prescription sales and partner payments into a single revenue line.
By our math, fourth-quarter total revenue dropped 50% from the third quarter to $37.8 million, and fell 85% from a year ago when the company booked large payments from Sanofi and Sarepta. Meanwhile, deferred revenue — cash already collected from Novartis that turns into revenue as Arrowhead finishes lab work — drained by another $13.4 million to $113.0 million.
The company reported $1.8 million in cost of product revenue for the year, proving it is shipping commercial boxes, but withheld the sales figure. Because partner revenue is shrinking as the Novartis balance runs down, investors cannot tell what doctors and insurers actually pay for REDEMPLO after rebates.
What to watch: the revenue footnote in the Form 10-K annual report. It must separate partner revenue from product sales so investors can calculate the net price per prescription.
Commercial Expansion Pushes Quarterly Operating Costs Higher
Preparing to sell REDEMPLO to a much larger patient group in 2027 is driving overhead higher before the revenue arrives. Full-year selling, general and administrative expenses — sales reps, marketing and corporate overhead — rose 63% to $202.0 million, while research and development costs — clinical trials and lab work — climbed 22% to $739.1 million.
- Fourth-quarter selling and overhead costs: $67.2 million by our math, up 78% from a year ago
- Fourth-quarter research costs: $190.5 million by our math, up 9% from a year ago
- Fourth-quarter operating expenses excluding the $215 million voucher: $259.4 million by our math, up from $245.3 million in the third quarter
- Fourth-quarter cash drain excluding the voucher: $158.9 million by our math
Even without the one-time $215 million voucher purchase, quarterly spending reached a new high for the year while revenue shrank, widening the annual operating loss to $707.2 million.
What to watch: quarterly selling and overhead spending in early 2027 as the sales force expands to cover more than 20,000 doctors for the sHTG launch.
Risks this quarter didn't answer
Three standing risks from prior quarters received no update in the year-end earnings release and await the full annual report or upcoming medical updates.
- Ionis patent lawsuit: no update in the release on the September 2025 suit claiming REDEMPLO infringes Ionis's patent; the Form 10-K legal footnote will show the current status.
- Obesity clinical data: the release did not include the expected late-2026 clinical update for fat-targeting drugs ARO-ALK7 and ARO-INHBE or the new obesity trial filing.
- Sarepta partnership scope: no breakdown of partner revenue after Sarepta took over certain preclinical tasks in the spring; the Form 10-K collaboration table will show the exact fourth-quarter contribution.
💲 Other KPIs
Cash and marketable securities fell by $373.9 million in the fourth quarter from $1,566.9 million in June, driven by the $215.0 million FDA voucher purchase and $158.9 million in operating cash use by our math. Total cash remains 29.8% higher than a year ago following January's $930 million stock and convertible note financings.
The average diluted share count rose 5.9% for the full fiscal year from 133.8 million in fiscal 2025, reflecting the January 2026 common stock offering and ongoing at-the-market share sales. Ending shares outstanding reached 141.3 million in September, up 4.1% from a year ago but nearly unchanged from 141.1 million in June.
🔮 Guidance
Unchanged. Arrowhead plans for a US commercial launch in severe hypertriglyceridemia in the second quarter of 2027, pending FDA approval. Because the regulator accepted the application into the STAR pilot program — which targets an action at least one month faster than a six-month priority review — the drugmaker kept its schedule without spending its Priority Review Voucher.
Unchanged. The biotech group still expects to finish its global Phase 3 trial of zodasiran for homozygous familial hypercholesterolemia (a rare genetic high-cholesterol disease) in mid-2027. Arrowhead completed enrollment during the year, expanding the study to 70 patients from an initial target of 60 due to high doctor and patient demand.
❓ Key Questions
What were net REDEMPLO sales in the fourth quarter?
Prescriptions rose 63% from the third quarter and weekly volume hit 50 to 60, but the release only shows $1.8 million in annual cost of product revenue. Investors need the dollar sales figure to see what insurers pay after discounts.
How many prescriptions are refills versus new patients?
Cumulative new-to-brand prescriptions reached 950 by September and 1,250 by mid-November. Because patients inject REDEMPLO once every three months, disclosing how many stay on the drug for their second and third doses will show true patient retention.
When will Arrowhead release the next obesity trial results?
Earlier in the year, executives aimed to share more clinical data on fat-targeting drugs ARO-ALK7 and ARO-INHBE before the end of 2026. The year-end release did not mention the obesity programs, leaving the timeline unclear.
What is the expected quarterly cash burn for 2027?
By our math, operating expenses excluding the $215 million voucher rose to $259.4 million in the fourth quarter as sales and overhead costs jumped 78% from a year ago. Investors need to know how much higher commercial spending will climb ahead of the sHTG launch.