Pharma Friday – Endocrine News Weekly roundup

One centers on a Phase 3 trial of TEPEZZA delivered subcutaneously via an on-body injector (OBI) in moderate-to-severe active thyroid eye disease (TED).

The other reports Regeneron’s submission to the FDA for priority review of garetosmab, a monoclonal antibody targeting Activin A, for fibrodysplasia ossificans progressiva (FOP), supported by the OPTIMA trial data.

The narratives cover trial design, primary and secondary endpoints, safety observations, and regulatory context.

Clinical study design and primary evidence for TEPEZZA OBI in TED

This is presented as statistically significant and clinically meaningful in the context of proptosis improvement.

A numerical trend favored TEPEZZA OBI for GO-QoL visual functioning subscale, though this did not reach statistical significance.

The most common adverse events occurring in 10% or more of participants included muscle spasms, tinnitus, weight decrease, ear discomfort, nausea, and diarrhea.

Expert commentary emphasizes the potential for broader patient access through a subcutaneous delivery approach that could mirror IV-level efficacy.

• The source summarizes two distinct regulatory and clinical developments reported by Endocrine News in early April 2026.
• Investigational approach: A Phase 3 study evaluated TEPEZZA given by subcutaneous injection using an on-body injector in adults with moderate-to-severe active TED.
• Primary endpoint and result: The trial met its primary endpoint with a 24-week placebo-controlled period showing a 77% proptosis response rate for TEPEZZA OBI, versus 19.6% with placebo.
• Secondary outcomes: Additional prespecified secondary endpoints demonstrated statistical significance and clinical relevance, including overall responder rate, proportion achieving a Clinical Activity Score (CAS) of 0 or 1, changes in diplopia across ordinal categories, diplopia response metrics, complete diplopia responder rate, and improvements in the Graves’ Ophthalmopathy Quality of Life (GO-QoL) appearance subscale at week 24.
• Safety profile: Adverse events aligned with TEPEZZA’s established safety expectations for IV administration, with the notable addition of mild-to-moderate injection-site reactions observed in some patients treated subcutaneously, not leading to treatment interruption or discontinuation.
• Context for TED: The description characterizes TED as a serious, progressive, and potentially vision-threatening autoimmune condition that can manifest with proptosis, diplopia, eye pain, redness, and swelling.

FDA for Priority Review as a therapy for adults with FOP.

The decision process is anticipated by an action date in August 2026.

HO can affect the jaw, spine, hip, and rib cage, with substantial impacts on speaking, eating, walking, and breathing; weight loss and mobility loss are noted as consequences.

Both doses substantially reduced new HO lesions at 56 weeks compared with placebo, with the primary endpoint showing a 94% reduction for the 3 mg/kg group (1 lesion vs 19 lesions; p=0.0274) and a 90% reduction for the 10 mg/kg group (2 lesions vs 19 lesions; p=0.0260).

A post-hoc analysis demonstrated greater than 99% reductions in mean total lesion volume for both doses versus placebo.

Common adverse reactions (incidence ≥30%) included epistaxis, increased hair growth, abscess, and acne.

Additional regulatory submissions are anticipated in other jurisdictions.

The safety and efficacy profile of garetosmab, and its potential utility in FOP, remain investigational and have not been fully approved by any authority at the time of the report.

• Regulatory submission: Regeneron’s garetosmab has been accepted by the U.S.
• Mechanistic target and rationale: Garetosmab is a monoclonal antibody that binds and inhibits Activin A, a protein implicated in the development of heterotopic ossification (HO) lesions in FOP.
• Disease context and burden: FOP is described as an ultra-rare, lifelong genetic disorder characterized by progressive HO within muscles, tendons, ligaments, and connective tissue, leading to considerable functional impairment and skeletal deformity.
• Trial evidence supporting BLA: The Biologics License Application is underpinned by data from the OPTIMA Phase 3 trial in adults with FOP, which evaluated two regimens of garetosmab (3 mg/kg and 10 mg/kg).
• Safety signals: Across all 63 participants aged 18 and older in OPTIMA, serious treatment-emergent adverse events occurred in a small number across the different dosing groups and placebo.
• Regulatory context and designation status: The FDA previously granted Fast Track and Orphan Drug Designation for garetosmab for HO prevention in FOP.

Safety observations align with the established TEPEZZA safety profile, with injection-site reactions being the primary new consideration for the subcutaneous format.

However, the article notes that regulatory status is contingent on FDA review, and ongoing international regulatory considerations are mentioned.

The safety results are characterized as acceptable within the trial context, though as with all investigational assets, broader post-marketing or real-world safety data would be required to fully characterize risk.

• The reported TEPEZZA OBI results are framed as extending the known efficacy of TEPEZZA IV, with a subcutaneous route intended to increase convenience and accessibility while maintaining IV-level clinical impact.
• For garetosmab, the BLA is rooted in robust efficacy signals from OPTIMA.
• The source acknowledges the seriousness of both conditions—TED and FOP—and underscores the potential implications of expanded administration options or targeted therapies for patient populations facing chronic or progressive disease courses.

The emphasis on Activin A blockade as a disease-modifying approach in FOP highlights a strategic focus on intervening in HO lesion development and burden.

• If TEPEZZA OBI gains regulatory approval or positive labeling, this subcutaneous delivery method could broaden access by offering a more convenient administration route without compromising efficacy, potentially reducing patient burden associated with IV infusions and clinic visits.
• The regulatory pathway for garetosmab remains contingent on FDA decision-making, with the Priority Review designation reflecting potential significance if approved.

• The source indicates that full study results for the TEPEZZA OBI trial will be presented at an upcoming medical congress, suggesting that some data remain to be disclosed or peer-reviewed in full.
• While the OPTIMA trial data are summarized with strong efficacy signals, the broader long-term safety profile and real-world applicability of garetosmab remain to be established outside trial conditions.
• The report notes that inclusion of garetosmab in Pharma Fridays does not imply endorsement, signaling a neutral editorial stance and the preliminary nature of regulatory conclusions.

• The TED-oriented update centers on a randomized, placebo-controlled Phase 3 design with a 24-week primary assessment period, focusing on objective proptosis outcomes and a suite of ocular and quality-of-life endpoints.
• The FOP-focused update relies on a Phase 3 trial with dosing arms for garetosmab, reporting both lesion count and lesion volume as key efficacy metrics across a 56-week horizon, with safety data collected as adverse events and treatment-emergent events.

• What will the full congress presentation reveal regarding long-term outcomes, durability of proptosis and diplopia improvements, and real-world tolerability of TEPEZZA OBI?
• How will regulatory agencies harmonize safety concerns, and will additional safety data emerge in broader patient populations or longer follow-up periods for garetosmab?
• Will the subcutaneous TEPEZZA option alter treatment sequencing or patient selection criteria in TED management, and how will payer dynamics influence adoption?

• The content reflects an industry-summary of select developments with emphasis on topline results and regulatory trajectories.