Rhythm Pharmaceuticals (RYTM) Q3 2026 earnings review
Rhythm's obesity launch gains patients, and its loss narrows
Rhythm Pharmaceuticals, a rare-disease drugmaker, grew sales rapidly in its second quarter selling Imcivree for US hypothalamic obesity while narrowing its operating loss. Global revenue climbed 29% from last quarter to $92 million, and global patients on paid therapy rose 20%. Chief executive David Meeker also began commercial sales in Japan in October, ahead of his year-end target.
| Global product revenue | $92.1M +29% from last quarter (+80% from a year ago) |
|---|---|
| US start forms in acquired HO | >700 up from >400 at the end of Q2 |
| Operating loss | $39.3M narrowed from $52.7M a year ago |
| Full-year operating expense outlook, excluding one-offs | Cut $10M middle of the range: $370M |
⚖️ Verdict: 🟢 Bullish
The story got better because the US launch kept its pace of about 300 new patient start forms in the quarter while insurance coverage more than doubled to 75% of commercial plans. Rhythm also used a new $750 million loan facility to pay LG Chem $350 million over four years, cutting future portfolio royalties to 1% without issuing shares. One caution: almost all of the $4 million sequential jump in international revenue came from lapping a French rebate charge rather than underlying patient growth.
The question now is how many of the 700 US patient start forms will turn into long-term paid prescriptions. Either widening insurance policies drive another jump in paid patients, or unstated dropout rates and pharmacy inventory swings slow US sales once the initial patient queue clears. Fourth-quarter US dispensed revenue and start-form additions will show which side is right.
🐂 Bull Case
US Launch Keeps Adding Patients and Insurance Coverage
Rhythm sells Imcivree (setmelanotide), a daily injection that reduces hunger and weight in rare neuroendocrine diseases. In March 2026, US regulators approved the drug for acquired hypothalamic obesity (HO), a severe weight condition caused by brain tumors or surgery. Critics worried that early prescriptions came only from a one-time backlog of waiting patients, but third-quarter numbers show steady new demand and much wider insurance coverage.
- Total US patient start forms: more than 700 by September 30, up by about 300 from June
- New forms excluding clinical trial patients: about 295 in the third quarter by our math, matching the prior quarter's pace
- Unique prescribing doctors: more than 500, up from about 300 in June, with about 25% writing repeat prescriptions
- Insurance policies covering the condition: 75% of commercial plans and 60% of Medicaid plans, up from 35% and 25% in June
- US sales from medicine dispensed to patients: up $15.1 million from last quarter
What to watch: fourth-quarter patient start forms and global patients on paid therapy. Another 250 to 300 forms would confirm that community doctors are still adopting the drug beyond the initial wave at major medical centers.
Japan Launch Starts Early With Hospitals Lined Up
"Our commercial launch in Japan represents another important milestone in a market with the potential to become our second largest," chief executive David Meeker said. Rhythm estimates that 5,000 to 8,000 people in Japan live with acquired hypothalamic obesity, compared with about 10,000 in the United States. Japanese regulators approved Imcivree in August, and the company began commercial sales on October 13, beating its year-end target.
The company built a local team of more than 50 employees to target roughly 350 priority hospitals where doctors treat brain tumors. By November, field staff had already met with about 300 of those hospitals and identified more than 1,000 patients who are likely eligible for the drug. Because doctors have already found those patients, sales in Japan can start contributing in the fourth quarter.
What to watch: international revenue growth in the fourth quarter and first quarter of 2027. Meaningful revenue gains outside the United States will show how quickly identified Japanese patients move onto paid prescriptions.
New Loan and LG Chem Deal Cut Royalties
Rhythm is developing bivamelagon, a daily pill licensed from LG Chem that targets the same hunger pathway as Imcivree. "Our restructured bivamelagon royalty agreement with LG Chem reflects our strong belief in the future potential of the portfolio," Meeker said. On November 2, Rhythm agreed to pay LG Chem $350 million over four years to cut the future royalty on its entire MC4R drug portfolio from a low-to-mid single-digit percentage down to 1%.
To fund the buyout without issuing new stock, the company secured a five-year loan facility for up to $750 million from HealthCare Royalty and Blackstone Life Sciences. Rhythm drew $250 million upfront and owes LG Chem $70 million within 15 business days, which raises its cash balance from $320.9 million at quarter-end to about $501 million by our math.
What to watch: interest expense starting in the fourth quarter. The new loan carries an interest rate of at least 5.6% (SOFR plus 4.60% with a 1% floor), which will increase quarterly financing costs while saving future sales royalties.
🐻 Bear Case
Next-Generation Pill Advances, But One Trial Slips
Rhythm wants to move patients to next-generation drugs—bivamelagon, a daily pill, and RM-718, a weekly injection—that did not cause widespread skin darkening in mid-stage trials. Supporters view the pipeline as de-risked because Rhythm chose bivamelagon for two late-stage trials: a 52-week study in acquired hypothalamic obesity starting by year-end, and a 26-week study in Prader-Willi syndrome, a genetic obesity disorder, planned for 2027.
However, clinical timelines continue to slip and regulatory hurdles remain. The Prader-Willi trial is still "pending alignment with the FDA", and Rhythm pushed enrollment completion for its Imcivree substudy in congenital hypothalamic obesity from the second half of 2026 into 2027. Meanwhile, the LG Chem deal commits Rhythm to $70 million now and $280 million over the next three Septembers before bivamelagon finishes Phase 3 testing.
What to watch: initiation of the bivamelagon Phase 3 trial in acquired hypothalamic obesity by December 31, 2026. A delay past year-end would show that manufacturing work for the pill is still holding back clinical execution.
International Sales Barely Grew Without One-Offs
Rhythm highlighted that revenue outside the United States rose 22%, or $4.4 million, from the second quarter to $24.7 million, and said reimbursed patients continued to grow. The presentation's revenue bridge shows that almost all of that sequential gain came from the absence of a second-quarter French government rebate charge, not from new international sales.
- Reported international revenue: $24.7 million, up $4.4 million from the second quarter
- Second-quarter French Contribution M rebate charge that did not repeat: $3.8 million
- Underlying international revenue growth from last quarter: $0.6 million, or 2.5% by our math
- US specialty pharmacy inventory benefit in the third quarter: $1.3 million, on top of a $2.9 million build in the second quarter
What to watch: fourth-quarter US specialty pharmacy inventory levels and French rebate adjustments. Because US shipments have exceeded prescriptions dispensed to patients for two straight quarters, an inventory drawdown would reduce reported US growth.
Risks this quarter didn't answer
Four standing concerns about prescription conversion, patient retention, and manufacturing costs were not answered in the earnings release or presentation.
- Start-form conversion rate: Rhythm reported that two-thirds of insurance approvals happen within 60 days, but still did not disclose what share of the 700 start forms have turned into paid prescriptions.
- Patient dropout rate in acquired hypothalamic obesity: undisclosed since launch; a figure near the 30% seen in Bardet-Biedl syndrome would lower long-term sales.
- Revenue split by disease: the release states that both acquired hypothalamic obesity and Bardet-Biedl syndrome grew in the US, without giving exact dollar figures for either.
- Cost of sales: rose to 13.2% of product revenue by our math, up from 12.5% in the second quarter and 10.7% a year ago, with no explanation in the release.
💲 Other KPIs
Rhythm's operating loss narrowed from $52.7 million a year ago and $48.6 million in the second quarter because product sales grew faster than staff and trial spending. Research and development fell by 32.8 percentage points of revenue from a year ago, and selling and administrative costs fell by 29.7 percentage points, even as cost of sales rose 2.5 points.
Cash and marketable securities declined by $10.0 million in the third quarter, a much smaller drop than the $48.3 million decrease in the first quarter and $9.7 million in the second. The balance excludes November's $250 million loan draw and $70 million payment to LG Chem, and the biotech group expects cash to fund operations for at least 24 months.
Money owed by customers and specialty pharmacies fell 3.2% from the second quarter by our math, even though product revenue jumped 29.3%. That compares with a 31% rise in the first quarter and an 18% rise in the second, showing that Rhythm collected cash faster from its distributors during the third quarter.
🔮 Guidance
Cut. Rhythm lowered the middle of its full-year spending plan—which excludes stock-based pay and fixed licensing fees—by $10 million, to $370 million, or 25.2% above 2025. By our math, after $261.2 million spent in the first nine months, the plan leaves $108.8 million for the fourth quarter, a 15.4% step-up from the third quarter's $94.2 million. This is the second straight cut after a $20 million reduction last quarter.
Cut. Management reduced the middle of its research and development spending range by $15 million, to $170 million, following a $20 million reduction in the second quarter when manufacturing work shifted into 2027. GAAP research and development rose 14.0% from a year ago in the third quarter to $52.5 million "primarily due to an increase in costs in chemistry, manufacturing, and controls (CMC) activity and clinical trial costs".
Raised. The drugmaker lifted the middle of its commercial and overhead spending plan by $5 million, to $200 million, after holding the range steady since the fourth quarter of 2025. The increase reflects higher staff, marketing, and promotional spending as Rhythm supports the US launch and rolls out Imcivree for acquired hypothalamic obesity in Japan.
❓ Key Questions
What share of the 700 start forms are paid prescriptions?
Rhythm reported more than 700 US start forms for acquired hypothalamic obesity and said two-thirds of insurance approvals happen within 60 days, but has not disclosed the exact conversion rate or how many patients have stopped taking the drug.
How much US revenue came from acquired hypothalamic obesity?
US product revenue grew by $16.5 million from the second quarter, driven by both acquired hypothalamic obesity and Bardet-Biedl syndrome. Disclosing the sales split would show whether the older Bardet-Biedl franchise is still growing on its own.
Why did cost of sales rise above 13% of revenue?
Cost of sales reached 13.2% of product revenue in the third quarter by our math, up from 12.5% in the second quarter and above the 10% to 12% range management previously indicated. Did royalty tiers, inventory write-offs, or free drug programs cause the increase?
What must the FDA agree to before the Prader-Willi trial?
Rhythm plans to start a 26-week Phase 3 study of bivamelagon in Prader-Willi syndrome in 2027 "pending alignment with the FDA". Investors need to know whether regulators have agreed to the six-month trial length and the hunger-score endpoint.