Muscle building and preservation

First posted October 13, 2026. Satellos registers NCT07872306, a masked phase 2 trial planning 51 adults with genetically confirmed facioscapulohumeral muscular dystrophy (FSHD1/2). Oral forazapadin/SAT-3247, an AAK1 inhibitor, 60 or 120 mg is compared with placebo. Primary outcomes are treatment-emergent adverse events through 48 weeks and dynamometry muscle-force change at 24 and 48 weeks. Functional, disease-specific outcomes cannot be generalized to healthy muscle building or weight-loss treatment.

Status/safety/U.S.: Not yet recruiting; no results or adverse-event rates. The protocol excludes recent GLP-1/GIP treatment. Registration is not marketing approval. Timing: December 15, 2026 estimated start; December 30, 2028 primary and June 30, 2029 final completion, all registry estimates rather than promised readouts.

Sources: ClinicalTrials.gov · NCT07872306.

Remaining gaps: All saved named registry records retrieved and all pages of bounded September5/6–October13 CT.gov discovery downloaded; 25 records screened selectively. Retrieval is not full appraisal. Worldwide registries, all publications/regulatory files, comprehensive harms and full audio/transcripts remain incomplete; prior full successful-check dates preserved. COURAGE in-press full journal tables and BELIEVE withdrawal harms remain unrecovered; PPMD October7 original replay not appraised.

Informal-source coverage: Original October1 COURAGE Reddit repost and October7 program comment were revisited; neither is new confirmation. Enobosarm Cantor direction remains a third-party account; original audio and actual phase3 initiation unverified. Gray-market sourcing discussion excluded.

Full coverage record.

Source date: October 1, 2026; newly appraised October 9. Evidence: sponsor/conference report, not a fully appraised journal publication. In COURAGE (NCT06299098), the low-dose portion continued semaglutide 2.4 mg plus placebo, trevogrumab 25 mg or 75 mg for 52 weeks. DXA lean-mass changes were −7.3% (95% CI −8.8 to −5.8), −5.8% (−6.8 to −4.7) and −4.2% (−5.3 to −3.1), respectively. Those are arm-specific intervals, not intervals for the between-group differences. The sponsor reports no meaningful additional weight loss with low-dose trevogrumab.

MRI/safety/limits: Evaluable thigh-MRI changes were −1.03 ±0.22, −0.29 ±0.12 and −0.32 ±0.13; ± values are standard errors and the release omits volume units and MRI denominators. Any adverse event was reported in 77% of pooled low-dose recipients versus 82% of controls; detailed serious-event and withdrawal counts are missing. The whole registry's 1,005 enrollment spans multiple portions and is not this analysis denominator. Body composition is not demonstrated strength, mobility or fewer falls. Earlier high-dose/garetosmab safety remains separate.

U.S./next: Investigational. A further older-adult phase 2 trial is planned, without a confirmed start/readout. The sponsor describes a Lancet paper as in press; full methods and harms remain pending.

October 1 sponsor report; primary registry.

Remaining gaps: All saved named NCT records refreshed and all pages of official overlap discovery screened (23 returned records). Search starts September 5/6 from the last full successful check, not October 6 alone. Incidental matches excluded; literature, international registries, all regulatory files and complete podcast/audio appraisal remain incomplete.; BELIEVE full withdrawal tables and HOPE-3 extension adverse-event tables remain missing. The October 7 PPMD webpage is still an invitation; a third-party transcript indicates a discussion but no original replay was appraised, so its elapsed date is not a new numerical result.

Informal-source coverage: Read October 1 original NTNPerformance repost of the COURAGE release; it supplies no independent corroboration. A BiohackingU October 7 comment calls trevogrumab phase 3, but the original sponsor/registry specify phase 2; gray-market sourcing context excluded. Revisited the September 9 Cantor enobosarm direction via third-party transcript; no actual phase 3 initiation confirmed, original audio unreviewed, stable claim remains unconfirmed without repeat alert.

Full coverage record.

Source date: October 5, 2026; WMS conference September 29–October 3. Evidence: Sponsor-reported HOPE-3 open-label extension in Duchenne muscular dystrophy.

Of 106 randomized participants, 98 entered the extension (49 per original arm); 82 had month-24 assessments. Delayed-start participants had modeled PUL 2.0 changes of −2.05 points during their placebo year and −0.49 during the following deramiocel year: difference 1.56 points (95% CI 0.47–2.64). The sponsor describes this as 76% less decline. Early-start modeled declines were −0.95 and −0.89 points in years one and two.

Limits/safety: Year two lacked randomized placebo control; models used each year’s own starting score. No alpha was allocated to extension analyses; the study was not powered for month-24 comparisons. Descriptive natural-history comparisons were unmatched. The release omits new adverse-event tables. This is upper-limb function in DMD, not healthy-adult muscle growth or GLP-1 muscle preservation.

U.S./next milestone: Investigational. PPMD webinar October 7, 2026 at 1 p.m. Eastern; FDA target November 22, 2026 is not guaranteed approval.

Original sponsor report.

Verified available: 2026-09-27; original posting date unknown. Evidence: Official conference abstract available before scheduled presentation.

The extension reports partial regain of weight, fat and visceral fat after stopping bimagrumab and/or semaglutide. NCT05616013 originally randomized 507 adults; treatment ended at week 72, imaging/labs followed to week 96 and weight/BP to week 104. In the baseline-prediabetes subset (n=129), 64.7–91.7% in bimagrumab-containing groups versus 18.8–35.7% on semaglutide alone retained HbA1c <5.7%.

Limitations: Actual abstract posting date unavailable: September 27 is verification, not publication/presentation date. Follow-up denominators, intervals and missing-data details absent. Prior switching/open-label extension and subgroup comparisons limit causal inference; no proof of lasting muscle function or diabetes remission.

Safety: LDL increases on bimagrumab monotherapy reversed below baseline after withdrawal. New adverse-event counts unavailable in the abstract.

U.S. status: Bimagrumab obesity combinations remain investigational.

Next milestone: Ken Attie presentation scheduled September 30, 2026, 15:15 CEST; seek full withdrawal tables.

EASD 2026 abstract 112; Official Lilly EASD schedule.

Source date: 2026-09-17. Evidence: Sponsor conference/development announcement.

Capricor will present HOPE-3 extension and delayed-start analyses in Duchenne muscular dystrophy. Of 106 participants originally randomized, 82 reached the 24-month timepoint: 40 originally assigned to deramiocel and 42 originally assigned to placebo. WMS runs September 29–October 3, with the oral presentation scheduled for October 3. The second year is open-label, with delayed-start and natural-history analyses.

Limitations: The notice provides no numerical 24-month effect or safety estimates. The extension does not maintain a randomized placebo comparison or establish general muscle-preservation efficacy. Earlier 12-month results are baseline evidence, not new September 17 efficacy findings.

Safety: New long-term safety tables pending.

U.S. status: Investigational. The sponsor lists an FDA target action date of November 22, 2026; this does not guarantee approval.

Next milestone: WMS, September 29–October 3, with the oral presentation on October 3. FDA target action date: November 22, 2026.

Capricor original September17 release.

Source date: 2026-09-17. Evidence: Trial registry; prospective study to follow.

A randomized study will measure whether resistance training preserves contractile thigh muscle during tirzepatide treatment. The Technical University of Munich study, NCT07777575, plans to enroll 150 adults with obesity and compare 24 weeks of resistance training with usual care. MRI endpoint assessment is blinded. The primary endpoint is change in contractile thigh muscle volume. The record was first posted on August 20 and updated on September 17; the trial is listed as recruiting.

Limitations: September 7 start is still estimated in the primary registry despite mirrors calling it actual. Muscle volume is distinct from strength and everyday function; no results available. This is a training adjunct study, not a new muscle drug.

Safety: Prospective safety data pending.

U.S. status: Approved tirzepatide is the background treatment; no new indication from registration.

Next milestone: Estimated primary/overall completion May 31, 2027, not a promised readout date.

NCT07777575 current primary registry.

Related findings:

• IVIG add-on improves early inflammatory-myopathy disease activity: TIME IS MUSCLE supports earlier IVIG add-on in a small newly diagnosed inflammatory-myopathy population.

Current position: formal trials now show that drugs can reduce loss of DXA lean mass during GLP-1 treatment. The reviewed programs remain investigational for obesity-related muscle preservation. Preserving lean tissue is promising, but does not by itself establish stronger muscles, fewer falls, or better long-term health. DXA lean mass also includes tissue other than skeletal muscle.

Bimagrumab — activin type II receptor blockade. The peer-reviewed BELIEVE trial (NCT05616013; March 2026) randomized 507 adults with obesity/overweight without diabetes. Its primary endpoint was weight change at 48 weeks; semaglutide was open-label. The high-dose combination lost 17.8 kg versus 14.2 kg with semaglutide 2.4 mg and 3.3 kg with placebo. DXA showed 92.3% of the combination's tissue loss was fat versus 71.1% with semaglutide. Most grip-strength comparisons were not significant; muscle spasms, diarrhea, acne and lipid changes warrant attention. The 72-week extension was open-label with post hoc analyses, so the larger extension headline is weaker evidence. Nature Medicine trial.

A separate bimagrumab/tirzepatide phase 2 study (NCT06643728) is active, not recruiting. The diabetes counterpart (NCT06901349) was withdrawn for strategic business reasons; that is not evidence the ongoing study failed.

Trevogrumab ± garetosmab — myostatin ± activin A blockade. The 599-person COURAGE trial (NCT06299098) reported complete 26-week results at EASD 2025. With semaglutide alone, DXA lean mass decreased 3.3 kg; adding lower/higher-dose trevogrumab reduced that loss to 1.5/1.9 kg. The triplet reduced loss to 0.9 kg and increased fat loss, but had substantially more discontinuations and two deaths. The sponsor reported no established causal association with those deaths. These are sponsor/conference results using an efficacy analysis that excludes post-discontinuation data; reported P values were not adjusted for multiple comparisons. Regeneron complete 26-week report. June 2026 presentations added body-composition analyses, not a verified new pivotal functional result. 2026 presentation list.

Apitegromab — selective inhibition of myostatin activation. EMBRAZE (NCT06445075) is now a full peer-reviewed paper (June 2026), not just a 2025 press release. It randomized 102 adults receiving tirzepatide. Among 87 completers with 24-week DXA, lean mass fell 1.6 kg with apitegromab versus 3.5 kg with placebo: 1.9 kg less loss. Fat loss was similar, 8.5 versus 8.0 kg. At eight weeks after stopping both treatments, the lean-mass difference had narrowed to 0.9 kg; exploratory physical-function results showed no notable between-group difference. Detailed safety results are summarized below; the small, mostly female sample and completer analysis limit generalization. Nature Medicine EMBRAZE report.

SRK-439 — next selective myostatin inhibitor. A phase 1 healthy-volunteer study is ongoing. It is not yet evidence of efficacy alongside GLP-1 treatment. Scholar Rock's recent emphasis is severe neuromuscular disease, and further obesity development needs to be followed explicitly. August 2026 status, company obesity partnering plans.

Enobosarm — formal oral selective androgen-receptor modulator program. Included only as Veru's regulated development program. Sponsor-reported QUALITY results in 168 adults aged at least 60 support lean-mass/function preservation with semaglutide, but were short and population-specific. The newer phase 2b PLATEAU trial enrolled 239 adults aged at least 65 with BMI at least 35; its primary outcome is incremental weight reduction, with DXA, stair-climb function, and bone density among secondary outcomes. August 2026 program update.

EMBRAZE: tirzepatide + apitegromab versus tirzepatide + placebo. Safety follow-up continued through week 40 (24 weeks of treatment plus 16 weeks off treatment), with 51 participants per arm. Any adverse event occurred in 39/51 (76%) versus 36/51 (71%); serious events in 1/51 (2%) each. Nausea was reported by 20 versus 16 participants, fatigue by 13 versus 6, and headache by 11 versus 5. Study-drug discontinuations due to adverse events were 2 versus 3; the paper does not separately enumerate each component stopped or study withdrawal. Deaths and total infusion-reaction incidence were not separately reported. Safety table, article and methods.

BELIEVE: semaglutide 2.4 mg + bimagrumab 30 mg/kg versus semaglutide 2.4 mg + bimagrumab placebo. The week-48 safety populations were 55 versus 56, distinct from 57 randomized per arm. Any adverse event occurred in 54/55 (98.2%) versus 51/56 (91.1%); serious events in 4/55 (7.3%) versus 6/56 (10.7%); adverse-event treatment discontinuations in 3/55 (5.5%) versus 5/56 (8.9%). Muscle spasms affected 63.6% versus 8.9%, acne 52.7% versus 8.9%, and diarrhea 49.1% versus 35.7%. One non-serious combination-arm episode was adjudicated as pancreatitis despite the investigator-coded row being zero. Adjusted LDL change was +11.1 ± 4.3 versus −14.0 ± 2.4 mg/dL (mean ± standard error). Safety table and footnotes, lipid results.

These are observed adverse events, not necessarily treatment-caused side effects. The small phase 2 comparisons cannot establish equal safety, a safety advantage, or rare-event risk. BELIEVE's separate weeks 48–72 extension and longer registry follow-up should not be mixed with these week-48 rates.

• Sponsor-announced: SRK-439 phase 1 topline anticipated late 2026; enobosarm PLATEAU interim DXA results Q1 2027, final topline Q4 2027. These are sponsor windows, not guaranteed dates; sources above.
• Completed regulatory action, different indication: FDA approved apitegromab for SMA on September 11, 2026, superseding the previously expected September 30 action date. Obesity-related muscle preservation remains investigational. See the focused update above. Earlier forecast retained for provenance: August regulatory status.
• No reliable public readout date verified: bimagrumab/tirzepatide efficacy or COURAGE's 52-week maintenance results. A registry completion date should not be presented as a publication deadline.

What would materially strengthen the case: replicated preservation of measured muscle, improvement in strength/function, durable benefit after withdrawal, and acceptable longer-term safety. No approval timing for obesity muscle preservation can responsibly be inferred from these phase 1/2 results.