Rhythm Pharmaceuticals Q3 Revenue Rises 79% on IMCIVREE Launch

Rhythm Pharmaceuticals reported a 79% year-over-year increase in third-quarter net product revenue as the U.S. launch of IMCIVREE for acquired hypothalamic obesity gained traction. The company also outlined plans to move oral MC4R agonist bivamelagon into two Phase 3 trials while expanding IMCIVREE’s international commercial footprint.

Net product revenue reached $92.1 million for the three months ended September 30, 2026, up from $51.3 million a year earlier and 29% from $71.3 million in the second quarter. Rhythm said 73% of quarterly revenue came from the U.S., with growth primarily driven by product dispensed to American patients following the acquired hypothalamic obesity launch.

The number of patients globally receiving IMCIVREE through reimbursed therapy increased 20% sequentially. Rhythm also cited a $1.3 million U.S. specialty-pharmacy inventory effect and a $4.4 million ex-U.S. benefit that included higher revenue and the normalization of a second-quarter charge in France.

U.S. acquired hypothalamic obesity launch gains traction

Between the March 19 FDA approval and September 30, Rhythm received more than 700 patient start forms for IMCIVREE in acquired hypothalamic obesity, including 71 forms from clinical-trial patients. About half of the forms were for adults older than 22, while approximately 30% involved patients ages 12 to 21 and 20% involved children ages 4 to 11.

The company reported start forms from more than 500 unique prescribers, with endocrinologists accounting for 80% and evenly divided between adult and pediatric specialists. About 25% of providers had submitted forms for more than one acquired hypothalamic obesity patient.

Rhythm said access and reimbursement continued to develop during the launch. Two-thirds of reimbursement approvals occurred in less than 60 days, and 75% were granted either at or without prior authorization. Positive coverage policies represented 75% of commercially insured lives and 60% of Medicaid covered lives as of quarter-end.

The company also reported continued growth in the number of Bardet-Biedl syndrome patients on therapy and said it had established a dedicated field force for that indication.

Japan launch underway, European preparations continue

Rhythm began selling IMCIVREE for acquired hypothalamic obesity in Japan on October 13. The company estimates that 5,000 to 8,000 people in Japan have the condition, based on its review of tumor registries and claims data.

Rhythm has more than 50 employees in Japan, including 16 hospital affairs leads and six scientific affairs managers. Its commercial strategy focuses on roughly 350 priority hospitals. Field teams had engaged with about 300 of those institutions and identified more than 1,000 patients considered likely to be eligible for IMCIVREE.

Country-level European launches are expected in 2027. Rhythm estimates acquired hypothalamic obesity prevalence at approximately 10,000 patients across Germany, France, Spain, Italy, the U.K. and the Netherlands. The German G-BA process has begun, while reimbursement dossiers have been submitted in France, Italy, the U.K., Spain and the Netherlands.

Bivamelagon headed for two Phase 3 studies

Rhythm plans to advance bivamelagon, a once-daily oral MC4R agonist, into global, placebo-controlled Phase 3 trials for acquired hypothalamic obesity and Prader-Willi syndrome.

The acquired hypothalamic obesity study is designed to run for 52 weeks, with BMI reduction as its primary endpoint. The Prader-Willi syndrome trial will last 26 weeks and use reduction in hyperphagia, measured by the HQ-CT, as its primary endpoint. Rhythm’s broader MC4R portfolio also includes weekly injectable candidate RM-718 and setmelanotide, marketed as IMCIVREE.

The company amended its exclusive bivamelagon license agreement with LG Chem, reducing the royalty on MC4R portfolio sales to 1% from a low-to-mid-single-digit rate. The new royalty takes effect January 1, 2029, or upon the first commercial sale of bivamelagon if that occurs earlier.

Under the amendment, Rhythm will pay an additional $350 million over four years, beginning with $70 million due within 15 business days of the amendment’s effective date. The remaining installments comprise $100 million in September 2027, $100 million in September 2028 and $80 million in September 2029. The agreement retains $30 million of development milestones and adds a new $200 million commercial milestone to the existing $175 million of commercial milestones, with revised sales thresholds applying across the MC4R portfolio.

Loss narrows as operating spending rises

Rhythm’s third-quarter net loss attributable to common stockholders narrowed to $42.4 million, or $0.61 per share, from $54.3 million, or $0.82 per share, a year earlier.

Research and development expense increased to $52.5 million from $46.0 million, while selling, general and administrative expense rose to $66.8 million from $52.4 million. Total third-quarter operating expenses were $119.2 million, including $25.0 million of stock-based compensation.

For full-year 2026, Rhythm anticipates non-GAAP operating expenses of $360 million to $380 million. That range includes $165 million to $175 million of R&D spending and $195 million to $205 million of SG&A expense. The company defines the measure as GAAP operating expenses excluding stock-based compensation and fixed consideration related to in-licensing and milestone payments. It did not provide a reconciliation to projected GAAP operating expenses because future stock-based compensation could not be calculated with confidence.

Rhythm ended September with $320.9 million in cash, cash equivalents and short-term investments, compared with $416.1 million a year earlier. That balance excluded a $250 million initial draw under a new $750 million term-loan facility and the subsequent $70 million payment tied to the licensing amendment. The five-year facility carries interest at SOFR plus 4.60%, subject to a 1% SOFR floor, and requires no amortization. Rhythm expects its available cash to fund planned operations for at least 24 months.

Key uncertainties identified by the company include clinical-trial enrollment and outcomes, regulatory approvals, commercialization execution, pricing and reimbursement, competition, international compliance requirements, liquidity and broader economic conditions.