Rhythm Pharmaceuticals Signals Momentum Despite Rising Costs

Rhythm Pharmaceuticals ((RYTM)) has held its Q1 earnings call. Read on for the main highlights of the call.

Rhythm Pharmaceuticals’ latest earnings call struck an optimistic tone as management highlighted steady revenue growth, accelerating international demand and a strong early launch for its new hypothalamic obesity indication, all backed by solid cash reserves. Executives acknowledged rising expenses and continued losses, but argued that commercial momentum and regulatory wins position the company for long‑term value despite near‑term volatility.

Quarterly Revenue Growth

Global net revenue reached $60.1 million in the first quarter of 2026, up 5% from $57 million in the prior quarter, underscoring steady top‑line momentum. The United States remained the core market, contributing 61% of total revenue and serving as the anchor for the company’s commercial performance.

International Revenue Acceleration

Revenue outside the U.S. climbed from $18.3 million to $23.2 million, a robust 27% sequential gain that outpaced domestic growth. Management credited higher volumes in Germany and France, as well as named‑patient markets such as Saudi Arabia and Greece, for fueling this expansion.

Growth in Reimbursed Patients

The number of patients on reimbursed therapy increased 8% quarter over quarter, signaling broader real‑world uptake of IMCIVREE. Growth was led by Bardet‑Biedl syndrome patients and international early access programs, which are helping build a base of recurring revenue.

Strong Early Hypothalamic Obesity Launch

The acquired hypothalamic obesity launch in the U.S. showed early strength, with more than 150 start forms submitted in the first six weeks after approval, including roughly 40 from clinical trial conversions. Around 110 unique prescribers, most of them new to IMCIVREE and primarily endocrinologists, wrote scripts as the salesforce expanded from 16 to 42 reps to tap an estimated 10,000‑patient HO market across the U.S. and Europe.

Regulatory and Market Access Milestones

Regulatory momentum remained a key theme as the company secured FDA approval for acquired HO in March and quickly followed with European Commission authorization after a positive CHMP opinion. In Japan, regulators have accepted the new drug application, and management is working toward potential approval and launch by late 2026, with broader EU country launches targeted for 2027.

Real‑World Evidence and Early Access Programs

Early access initiatives in France and Italy have generated meaningful experience with reimbursed patients, laying groundwork for future broader launches. Notably, France’s AP1 program has produced real‑world data from more than 60 HO patients, some treated for up to a year, with results slated for presentation at the European Congress of Endocrinology.

Cash Position and Runway

The company ended the quarter with about $341 million in cash, cash equivalents and short‑term investments, providing an estimated operational runway of at least 24 months. This liquidity gives management flexibility to fund commercial expansion, manufacturing investments and clinical programs without immediate financing pressure.

Pipeline and Clinical Milestones

Management emphasized that pipeline development remains on track, with a series of near‑term catalysts expected. Upcoming readouts include six‑month data in Prader‑Willi syndrome, midyear updates for RM‑718, Part C HO results on the next earnings call and ongoing CMC work to support a Phase III start of bivamelagon in HO by the end of 2026.

GAAP Losses and Cash Burn

Despite revenue gains, Rhythm posted a GAAP net loss of $0.83 per share in the quarter, highlighting the cost of its expansion. Operating activities consumed approximately $44.2 million of cash, underscoring that profitability remains a medium‑term goal rather than an immediate milestone.

Sharp Increase in SG&A Spending

Selling, general and administrative expenses jumped to $63.6 million from $39.1 million a year earlier, a 62.7% increase reflecting the HO launch build‑out. The company cited higher headcount, stock‑based compensation and stepped‑up marketing as it scales its commercial infrastructure.

Higher R&D Investment

Research and development expenses rose to $41.7 million from $37.0 million in the prior year’s quarter, representing a roughly 12.7% increase. The uptick primarily reflects expanded staffing and supports the broader clinical and manufacturing agenda around IMCIVREE and next‑generation assets.

Revenue Variability and Inventory Effects

Management cautioned that revenue may remain lumpy in the near term, partly because of specialty pharmacy inventory patterns and variable order timing from named‑patient markets. A prior $1.8 million inventory build in the fourth quarter, coupled with uneven ordering cycles, can shift sales recognition between quarters.

Payer Policy and Reimbursement Uncertainty

While early payer responses and initial approvals for HO have been encouraging, leadership warned that formal coverage policies could take three to nine months to settle. That timeline introduces uncertainty around payer mix and realized net pricing per patient as insurers refine their approaches to this rare disease therapy.

Launch Conversion Dynamics

The company noted that most prescribers have to date written only a single prescription, reflecting an initial test‑and‑learn phase rather than immediate broad adoption. Future growth beyond trial patients will depend on patients’ visit schedules and ongoing physician education, suggesting that HO uptake will build steadily rather than surge all at once.

Japan Cohort Efficacy Nuances

In discussing clinical data, management flagged that placebo‑adjusted BMI reductions in the Japanese cohort were modestly smaller than in the full 142‑patient study. They attributed this in part to the fact that placebo patients in Japan did not gain weight as Western counterparts did, introducing some uncertainty given small sample sizes and potential cultural or lifestyle differences.

Forward‑Looking Guidance and Outlook

For 2026, Rhythm reaffirmed non‑GAAP operating expense guidance of $385 million to $415 million, split roughly evenly between R&D and SG&A, with spending expected to climb as CMC and clinical supply needs grow. The company also reiterated its commercial expectations, including continued growth in reimbursed patients, phased HO payer policy adoption over several months, international launch timelines into 2027 and a planned Phase III start for bivamelagon in HO by year‑end 2026.

Rhythm’s earnings call painted a picture of a company trading near‑term losses and expense growth for durable market positioning in a specialized obesity niche. Investors will need to balance the promise of expanding indications, international launches and a deepening pipeline against ongoing cash burn and reimbursement uncertainty, but management’s confident tone suggests a clear strategic path ahead.