Rhythm Pharmaceuticals, Inc. Q1 FY2026 earnings call

• Base business: Ongoing progress in VBS with growing awareness of the disease and adaptation to connect with right healthcare providers. - Acquired HO: FDA approval on March 19th, broad label, expanded commercial organization to 42 sales reps and scaled patient services team, received over 150 start forms in six weeks, 110 unique prescribers. - International: European Commission granted marketing authorization for acquired HO, rapid progress towards Japan approval with 50 employees in Japan, pre-launch tactics in place. - BBS: Steady growth in prescriptions, some patients transitioned insurance plans but most returned to reimbursed therapy.

In the first quarter of 2026, revenues were $60 million. For BBS, there was steady growth in prescriptions with some patients transitioning insurance plans but most returned to reimbursed therapy. For acquired HO, estimated to be approximately twice the size of BBS with 10,000 patients in US and Europe and 5,000 - 8,000 in Japan, there was a strong start with over 150 start forms in six weeks, 40 of which were for clinical trial patients, and 110 unique prescribers. Revenue outside the US increased from $18.3 million to $23.2 million in Q1, driven by increased sales volumes in Germany, France, and certain name patient sales markets. US revenue was affected by specialty pharmacy inventory changes and patient insurance plan transitions, but then returned to Q4 levels.

• Expect non-GAAP operating expenses in fiscal year 2026 to be approximately $385 to $415 million, comprised of non-GAAP R&D of approximately $197 to $213 million, and non-GAAP SG&A expenses of approximately $188 to $202 million. - Pending late-breaking abstract acceptance, goal to share Dr. Miller's six-month data in PWS at ENDO meeting in June. Anticipate sharing 718 data mid-year and Part C results in HO and potentially available data in PWS at Q2 earnings call. CMC work and BIVA bioequivalent studies for new formulation underway with goal to start Phase III trial with BIVA-Melegon in HO by end of 2026.

Q: On patient start forms and identification, update on number and where from; A: Continued progress, 2000 number increased, vast majority of start forms from physicians engaged prior to approval.

Q: On early launch progress sustainability, cadence; A: Pleased with early six weeks, trial conversions continue, most patients come from regularly scheduled visits.

Q: On 110 prescribers makeup; A: Vast majority wrote one script, breadth beyond priority accounts.

Q: On gating factors for doctors prescribing second/third patient; A: Pace of patient visits and education on other causes of AHO.

Q: On reimbursement dynamics for HO patients; A: Early in launch, payer mix varies, education from BBS launch helpful.

Q: On HO launch start forms vs expectations; A: Pleased with speed, start forms higher than BBS launch, some payers approved quicker.

Q: On PWS clinical value-add of setmelanotide; A: Biology suggests both reduction in hyperphagia symptoms and weight decrease.

Q: On Japan HO market feedback and launch trajectory; A: KOLs concerned about disease, engaged early, patient identification ongoing.

Q: On HO launch start forms vs BBS and patient pool diversity; A: Higher start forms than BBS, majority tumor-related but broader label covers other causes.

Q: On Prader-Willi syndrome trial design for XUS approval; A: Expect label with hyperphasia reduction and weight/bMI decrease