GSK-2881078

updated

GSK-2881078 is an oral selective androgen receptor modulator with no marketed product and no approval documented in the sources reviewed. Phase 1 and 1b studies reported greater lean mass than placebo, but the only efficacy study in a patient population, a phase 2A trial in 97 people with COPD, left leg-strength intervals crossing zero for women and for men on the kilogram measure and showed no change in patient-reported outcomes. HDL cholesterol, sex hormone-binding globulin and liver enzymes were affected, and no study found reports testosterone, LH or FSH.

Selective androgen receptor modulator (SARM)

  • An openFDA Drugs@FDA query for GSK2881078 on 9 October 2026 returned no matching application; no FDA-approved GSK-2881078 product was located.
  • In the first-in-human study, HDL cholesterol and sex hormone-binding globulin fell in a dose-dependent way; in women at 0.35 mg the differences from placebo were -0.518 mmol/L and -39.1 nmol/L.
  • A phase 1b study in healthy older men and postmenopausal women reported greater lean mass accrual than placebo at all dose levels, but its abstract gives no number.
  • In the phase 2A COPD trial (47 women and 50 men, 13 weeks, with home exercise), 90% intervals for leg-strength differences crossed zero for women on both measures and for men on the kilogram measure.
  • Three studies are registered; no phase 3 study is registered, and the two phase 1 records have no posted results.
  • A systematic review reports that two individuals exposed to GSK2881078 in a clinical trial had rhabdomyolysis.

What is GSK-2881078, and has anything been approved?

GSK-2881078 is a research compound, a selective androgen receptor modulator with no marketed product. An openFDA query on 9 October 2026 returned no GSK2881078 application, and no approval in any country is documented in the sources reviewed.

GSK-2881078 is C14H13F3N2O2S (330.33 g/mol, CAS 1539314-06-1, PubChem CID 86709174), a single defined enantiomer, 1-[(2R)-1-methylsulfonylpropan-2-yl]-4-(trifluoromethyl)indole-5-carbonitrile. Listed synonyms include GSK2881078 and GSK 2881078. There is no salt form and no marketed product, so a vendor powder has no reference standard to be compared against.

An openFDA Drugs@FDA exact brand-name and generic-name query for GSK2881078 returned no matching application on 9 October 2026. That supports the US-scoped statement that no FDA-approved GSK-2881078 product was located. A systematic review of SARM safety states separately that SARMs are not FDA approved and that obtaining SARMs for personal use is illegal. No approval in any country is documented in the sources reviewed.

PubChem CID 86709174: C14H13F3N2O2S, 330.33 g/mol, single defined enantiomer

Chemical identity record

National Library of Medicine. PubChem compound record CID 86709174 (GSK-2881078).

GSK-2881078: PubChem CID 86709174, C14H13F3N2O2S, 330.33 g/mol, CAS 1539314-06-1. The record resolves to a single defined enantiomer, 1-[(2R)-1-methylsulfonylpropan-2-yl]-4-(trifluoromethyl)indole-5-carbonitrile. Listed synonyms include GSK2881078 and GSK 2881078. There is no salt form and no marketed product, so a vendor powder has no reference standard to be compared against.

Participants / model
Chemical identity, not a clinical population
Treatment
Defined molecule, no approved formulation
Follow-up
Not applicable
Study design
NLM chemical record
Funding
not stated in the source

Identity record only; it says nothing about efficacy or safety.

Read the original source
openFDA query, 9 October 2026: no GSK2881078 application returned

Regulatory record

U.S. Food and Drug Administration. openFDA Drugs@FDA API query for brand name and generic name GSK2881078, run on 9 October 2026.

An openFDA Drugs@FDA exact brand-name and generic-name query for GSK2881078 returned no matching application on 9 October 2026. This supports the US-scoped statement that no FDA-approved GSK-2881078 product was located. A systematic review of SARM safety states separately that SARMs are not FDA approved and that obtaining SARMs for personal use is illegal.

Participants / model
FDA application database, not a clinical population
Treatment
Exact substance-name search
Follow-up
Query run on 9 October 2026
Study design
Database query
Funding
not stated in the source

A US-scoped search result. It is not a statement about approvals in other countries.

Read the original source

What did the early studies in healthy people find?

In the first-in-human study, exposure rose in proportion to dose and the half-life was greater than 100 hours. A phase 1b study in older men and postmenopausal women reported greater lean mass accrual than placebo at all dose levels, with women responding more at lower doses than men.

In the first-in-human study, 10 healthy young men received a single dose of 0 mg, 0.05 mg, 0.1 mg or 0.2 mg or matching placebo (Part A). Repeat-dose cohorts (Part B) in men (n=65) were 0.05, 0.2, then 0.08, 0.24, 0.48, 0.75 mg or placebo, and in women (n=24) 0.24 mg, 0.35 mg or placebo, for 7 days at 0.5 mg and 14 days for other doses. Exposure rose in proportion to dose, with a half-life greater than 100 hours. There were no significant effects on vital signs, electrocardiograms, cardiac telemetry or standard clinical laboratory studies.

The phase 1b study was randomized, placebo-controlled, parallel-group, repeat-dose and dose-escalating, in healthy older men and postmenopausal women (three cohorts of each). Dosing was twice daily for the first 3 days then once daily for up to 53 days, with repeated dual-energy X-ray absorptiometry and MRI cross-sectional thigh scans. Compared with placebo there was greater lean mass accrual at all dose levels, and women had a greater response at lower doses than men.

The abstract reports no numeric lean mass change, no kilogram figure and no participant count, so none is given here. A separate cohort found the effect of CYP3A4 inhibition on PK unlikely to be of clinical significance.

First-in-human: 10 men single dose, 65 men and 24 women repeat dose; HDL and SHBG fell

Clinical trial

Clark RV et al. Br J Clin Pharmacol. 2017;83(10):2179-2194. PMID 28449232.

Part A: 10 healthy young men received a single dose of 0 mg, 0.05 mg, 0.1 mg or 0.2 mg or matching placebo. Part B repeat-dose cohorts in men (n=65) were 0.05, 0.2, then 0.08, 0.24, 0.48, 0.75 mg or placebo, and in women (n=24) 0.24 mg, 0.35 mg or placebo, for 7 days at 0.5 mg and 14 days for other doses. Exposure rose in proportion to dose, with a half-life greater than 100 hours. There were no significant effects on vital signs, electrocardiograms, cardiac telemetry or standard clinical laboratory studies. A dose-response effect was observed on lowering both high-density lipoprotein (HDL) and sex hormone-binding globulin (SHBG); in females at 0.35 mg the differences from placebo were -0.518 mmol/L (95% CI -0.703 to -0.334) for HDL and -39.1 nmol/L (95% CI -48.5 to -29.7) for SHBG. Women showed greater sensitivity to these parameters at lower doses than men. Drug-related adverse events were mild. One woman developed a drug rash and was withdrawn. Two men had elevated creatine phosphokinase after physical exertion during follow-up. A serious adverse event occurred in a subject on placebo.

Participants / model
10 healthy young men (single dose); 65 men and 24 women (repeat dose)
Treatment
Oral GSK2881078, 0.05 to 0.75 mg, or placebo
Follow-up
Single dose (Part A); 7 days at 0.5 mg and 14 days for other doses (Part B)
Study design
Original phase 1 trial with placebo
Funding
not stated in the source

Endpoints were PK, vital signs, ECG, telemetry, HDL, SHBG and adverse events. The half-life is given only as greater than 100 hours.

Read the original source
Phase 1b: older men and postmenopausal women, more lean mass than placebo at all doses, no number given

Clinical trial

Neil D et al. J Clin Endocrinol Metab. 2018;103(9):3215-3224. PMID 29982690.

In a randomized, placebo-controlled, parallel-group, repeat-dose, dose-escalation study in healthy older men and postmenopausal women (three cohorts of each), dosing was twice daily for the first 3 days then once daily for up to 53 days, with repeated dual-energy X-ray absorptiometry and MRI cross-sectional thigh scans. Compared with placebo there was greater lean mass accrual at all dose levels, and women had a greater response at lower doses than men. Transient elevations of alanine aminotransferase were observed. No serious adverse events were reported. A separate cohort found the effect of CYP3A4 inhibition on PK unlikely to be of clinical significance. The abstract reports no numeric lean mass change, no kilogram figure and no participant count.

Participants / model
Healthy older men and postmenopausal women
Treatment
Oral GSK2881078 or placebo, twice daily for 3 days then once daily for up to 53 days
Follow-up
Up to 53 days
Study design
Randomized, placebo-controlled, parallel-group, repeat-dose, dose-escalation phase 1b study
Funding
not stated in the source

The abstract gives no lean mass figure, so the page gives none. Endpoints were lean mass by DXA and thigh MRI, PK, ALT and tolerability.

Read the original source

What did the COPD study show?

In 97 patients with COPD, 13 weeks of GSK-2881078 with a home exercise programme raised lean body mass. The 90% intervals for leg-strength differences versus placebo crossed zero for women on both measures and for men on the kilogram measure, and patient-reported outcomes did not change.

The phase 2A trial, registered as NCT03359473, randomized 47 postmenopausal women and 50 men with COPD (FEV1 30 to 65% predicted, short physical performance battery 3 to 11) 1:1 to once-daily placebo or oral GSK-2881078 (women 1.0 mg, men 2.0 mg) for 13 weeks, with a concurrent home exercise programme of strength training and physical activity. It is the only efficacy study in a patient population.

Differences in adjusted mean change from baseline in one-repetition-maximum leg strength versus placebo were, for women, 8.0 kg (90% CI -2.5 to 18.4) and 5.2% (90% CI -4.7 to 15.0), and for men, 11.8 kg (90% CI -0.5 to 24.0) and 7.0% (90% CI 0.5 to 13.6). Only the men's percentage result excluded zero, and these are 90% intervals, not 95%. Lean body mass increased, but no changes in patient-reported outcomes were observed.

Phase 2A in COPD: 97 patients, 13 weeks, leg-strength 90% intervals crossed zero, patient-reported outcomes unchanged

Randomized controlled trial

Mohan D et al. Thorax. 2023;78(3):258-266. PMID 36283827.

47 postmenopausal women and 50 men with COPD (FEV1 30 to 65% predicted, short physical performance battery 3 to 11) were randomized 1:1 to once-daily placebo or oral GSK2881078 (women 1.0 mg, men 2.0 mg) for 13 weeks with a concurrent home exercise programme of strength training and physical activity. Differences in adjusted mean change from baseline in one-repetition-maximum leg strength versus placebo were, for women, 8.0 kg (90% CI -2.5 to 18.4) and 5.2% (90% CI -4.7 to 15.0); for men, 11.8 kg (90% CI -0.5 to 24.0) and 7.0% (90% CI 0.5 to 13.6). Only the men's percentage result excluded zero, and the intervals are 90%, not 95%. Lean body mass increased, but no changes in patient-reported outcomes were observed. Reversible reductions in HDL cholesterol and transient elevations in hepatic transaminases were the main treatment-related safety findings.

Participants / model
47 postmenopausal women and 50 men with COPD and impaired physical function
Treatment
Oral GSK2881078, 1.0 mg (women) or 2.0 mg (men) once daily, or placebo, with a home exercise programme
Follow-up
13 weeks
Study design
Randomized placebo-controlled phase 2A trial
Funding
not stated in the source

The intervals are 90%, not 95%. Endpoints were leg strength by 1RM, lean body mass, physical function, patient-reported outcomes and safety.

Read the original source
Registry, 9 October 2026: three studies (99, 108 and 97 participants); two have no posted results

Trial registry record

ClinicalTrials.gov query for GSK2881078 run on 9 October 2026; records NCT02045940, NCT02567773 and NCT03359473.

A ClinicalTrials.gov query on 9 October 2026 returned three studies: NCT02045940 (phase 1, n=99, completed, no results posted), NCT02567773 (phase 1, n=108, completed, no results posted) and NCT03359473 (phase 2, n=97, completed, results posted). No study beyond phase 2 is registered. The two phase 1 records without posted results show that studies were run, not efficacy or safety.

Participants / model
Records returned, not a population
Treatment
Not applicable
Follow-up
Query run on 9 October 2026
Study design
Registry query
Funding
not stated in the source

The link opens the phase 2 record, NCT03359473, which has posted results.

Read the original source

Is the claim of lean mass gains at low doses in phase 1 data accurate?

Partly. The phase 1b study reported greater lean mass accrual than placebo at all dose levels, but its abstract gives no number, women responded more than men at lower doses, and HDL cholesterol, SHBG and liver enzymes were affected.

Sellers describe GSK-2881078 as a research compound for muscle weakness and reduced mobility, with lean mass increases documented in phase 1 human data at low doses.

The claim is accurate on its face: in the phase 1b study in healthy older men and postmenopausal women, lean mass accrual was greater than placebo at all dose levels. It is incomplete in three ways. The published abstract reports no number for the lean mass change. Women responded more than men at lower doses. And HDL cholesterol and sex hormone-binding globulin fell in a dose-dependent way in the first-in-human study, while transaminases rose in two separate studies.

A systematic review of 9 randomized trials (970 patients, mean age 57.1 years, range 35.3 to 75.9; mean follow-up 80 days, range 14 to 180) covering six SARMs including GSK2881078 reported pooled before-and-after means: lean body mass 49.46 to 50.86 kg, fat mass 21.99 to 21.85 kg, stair climbing power 352.24 to 315.16 W and leg press 1822.77 to 2191.27 N. These are pooled means across six different molecules, not placebo-controlled effect sizes for GSK-2881078.

Phase 1b: older men and postmenopausal women, more lean mass than placebo at all doses, no number given

Clinical trial

Neil D et al. J Clin Endocrinol Metab. 2018;103(9):3215-3224. PMID 29982690.

In a randomized, placebo-controlled, parallel-group, repeat-dose, dose-escalation study in healthy older men and postmenopausal women (three cohorts of each), dosing was twice daily for the first 3 days then once daily for up to 53 days, with repeated dual-energy X-ray absorptiometry and MRI cross-sectional thigh scans. Compared with placebo there was greater lean mass accrual at all dose levels, and women had a greater response at lower doses than men. Transient elevations of alanine aminotransferase were observed. No serious adverse events were reported. A separate cohort found the effect of CYP3A4 inhibition on PK unlikely to be of clinical significance. The abstract reports no numeric lean mass change, no kilogram figure and no participant count.

Participants / model
Healthy older men and postmenopausal women
Treatment
Oral GSK2881078 or placebo, twice daily for 3 days then once daily for up to 53 days
Follow-up
Up to 53 days
Study design
Randomized, placebo-controlled, parallel-group, repeat-dose, dose-escalation phase 1b study
Funding
not stated in the source

The abstract gives no lean mass figure, so the page gives none. Endpoints were lean mass by DXA and thigh MRI, PK, ALT and tolerability.

Read the original source
First-in-human: 10 men single dose, 65 men and 24 women repeat dose; HDL and SHBG fell

Clinical trial

Clark RV et al. Br J Clin Pharmacol. 2017;83(10):2179-2194. PMID 28449232.

Part A: 10 healthy young men received a single dose of 0 mg, 0.05 mg, 0.1 mg or 0.2 mg or matching placebo. Part B repeat-dose cohorts in men (n=65) were 0.05, 0.2, then 0.08, 0.24, 0.48, 0.75 mg or placebo, and in women (n=24) 0.24 mg, 0.35 mg or placebo, for 7 days at 0.5 mg and 14 days for other doses. Exposure rose in proportion to dose, with a half-life greater than 100 hours. There were no significant effects on vital signs, electrocardiograms, cardiac telemetry or standard clinical laboratory studies. A dose-response effect was observed on lowering both high-density lipoprotein (HDL) and sex hormone-binding globulin (SHBG); in females at 0.35 mg the differences from placebo were -0.518 mmol/L (95% CI -0.703 to -0.334) for HDL and -39.1 nmol/L (95% CI -48.5 to -29.7) for SHBG. Women showed greater sensitivity to these parameters at lower doses than men. Drug-related adverse events were mild. One woman developed a drug rash and was withdrawn. Two men had elevated creatine phosphokinase after physical exertion during follow-up. A serious adverse event occurred in a subject on placebo.

Participants / model
10 healthy young men (single dose); 65 men and 24 women (repeat dose)
Treatment
Oral GSK2881078, 0.05 to 0.75 mg, or placebo
Follow-up
Single dose (Part A); 7 days at 0.5 mg and 14 days for other doses (Part B)
Study design
Original phase 1 trial with placebo
Funding
not stated in the source

Endpoints were PK, vital signs, ECG, telemetry, HDL, SHBG and adverse events. The half-life is given only as greater than 100 hours.

Read the original source
Phase 2A in COPD: 97 patients, 13 weeks, leg-strength 90% intervals crossed zero, patient-reported outcomes unchanged

Randomized controlled trial

Mohan D et al. Thorax. 2023;78(3):258-266. PMID 36283827.

47 postmenopausal women and 50 men with COPD (FEV1 30 to 65% predicted, short physical performance battery 3 to 11) were randomized 1:1 to once-daily placebo or oral GSK2881078 (women 1.0 mg, men 2.0 mg) for 13 weeks with a concurrent home exercise programme of strength training and physical activity. Differences in adjusted mean change from baseline in one-repetition-maximum leg strength versus placebo were, for women, 8.0 kg (90% CI -2.5 to 18.4) and 5.2% (90% CI -4.7 to 15.0); for men, 11.8 kg (90% CI -0.5 to 24.0) and 7.0% (90% CI 0.5 to 13.6). Only the men's percentage result excluded zero, and the intervals are 90%, not 95%. Lean body mass increased, but no changes in patient-reported outcomes were observed. Reversible reductions in HDL cholesterol and transient elevations in hepatic transaminases were the main treatment-related safety findings.

Participants / model
47 postmenopausal women and 50 men with COPD and impaired physical function
Treatment
Oral GSK2881078, 1.0 mg (women) or 2.0 mg (men) once daily, or placebo, with a home exercise programme
Follow-up
13 weeks
Study design
Randomized placebo-controlled phase 2A trial
Funding
not stated in the source

The intervals are 90%, not 95%. Endpoints were leg strength by 1RM, lean body mass, physical function, patient-reported outcomes and safety.

Read the original source
SARM class review: 9 trials, 970 patients, six SARMs, pooled before-and-after means

Systematic review and meta-analysis

Wen J et al. Clin Endocrinol (Oxf). 2025;102(1):3-27. PMID 39285652.

The review included 9 studies and 970 patients, mean age 57.1 years (range 35.3 to 75.9) and mean follow-up 80 days (range 14 to 180), covering six SARMs including GSK2881078. Mean lean body mass went from 49.46 kg before the intervention to 50.86 kg after, and mean fat mass from 21.99 kg to 21.85 kg. Mean stair climbing power fell from 352.24 W to 315.16 W, while mean one-repetition-maximum leg press rose from 1822.77 N to 2191.27 N.

Participants / model
970 patients across 9 randomized trials, mean age 57.1
Treatment
Six different SARMs, oral
Follow-up
Mean follow-up 80 days (range 14 to 180)
Study design
Systematic review of randomized trials
Funding
not stated in the source

These are pooled before-and-after means across six different molecules, not placebo-controlled effect sizes for GSK-2881078.

Read the original source

How large is the registered development program?

Three studies are registered: two phase 1 studies (99 and 108 participants) with no posted results and one phase 2 study (97 participants) with results. No phase 3 study is registered.

A ClinicalTrials.gov query on 9 October 2026 returned three studies: NCT02045940 (phase 1, 99 participants, completed, no results posted), NCT02567773 (phase 1, 108 participants, completed, no results posted) and NCT03359473 (phase 2, 97 participants, completed, results posted). No phase 3 study is registered.

The two phase 1 records without posted results show that studies were run, not whether the compound worked or was safe. Nothing newer than the 2023 COPD report appears in the records reviewed.

Registry, 9 October 2026: three studies (99, 108 and 97 participants); two have no posted results

Trial registry record

ClinicalTrials.gov query for GSK2881078 run on 9 October 2026; records NCT02045940, NCT02567773 and NCT03359473.

A ClinicalTrials.gov query on 9 October 2026 returned three studies: NCT02045940 (phase 1, n=99, completed, no results posted), NCT02567773 (phase 1, n=108, completed, no results posted) and NCT03359473 (phase 2, n=97, completed, results posted). No study beyond phase 2 is registered. The two phase 1 records without posted results show that studies were run, not efficacy or safety.

Participants / model
Records returned, not a population
Treatment
Not applicable
Follow-up
Query run on 9 October 2026
Study design
Registry query
Funding
not stated in the source

The link opens the phase 2 record, NCT03359473, which has posted results.

Read the original source
Phase 2A in COPD: 97 patients, 13 weeks, leg-strength 90% intervals crossed zero, patient-reported outcomes unchanged

Randomized controlled trial

Mohan D et al. Thorax. 2023;78(3):258-266. PMID 36283827.

47 postmenopausal women and 50 men with COPD (FEV1 30 to 65% predicted, short physical performance battery 3 to 11) were randomized 1:1 to once-daily placebo or oral GSK2881078 (women 1.0 mg, men 2.0 mg) for 13 weeks with a concurrent home exercise programme of strength training and physical activity. Differences in adjusted mean change from baseline in one-repetition-maximum leg strength versus placebo were, for women, 8.0 kg (90% CI -2.5 to 18.4) and 5.2% (90% CI -4.7 to 15.0); for men, 11.8 kg (90% CI -0.5 to 24.0) and 7.0% (90% CI 0.5 to 13.6). Only the men's percentage result excluded zero, and the intervals are 90%, not 95%. Lean body mass increased, but no changes in patient-reported outcomes were observed. Reversible reductions in HDL cholesterol and transient elevations in hepatic transaminases were the main treatment-related safety findings.

Participants / model
47 postmenopausal women and 50 men with COPD and impaired physical function
Treatment
Oral GSK2881078, 1.0 mg (women) or 2.0 mg (men) once daily, or placebo, with a home exercise programme
Follow-up
13 weeks
Study design
Randomized placebo-controlled phase 2A trial
Funding
not stated in the source

The intervals are 90%, not 95%. Endpoints were leg strength by 1RM, lean body mass, physical function, patient-reported outcomes and safety.

Read the original source

How does GSK-2881078 work, and what does the body do with it?

GSK-2881078 is a selective androgen receptor modulator. In two cell assays its potency differed about a thousand-fold between systems, and in the first-in-human study its half-life was greater than 100 hours.

In two in vitro bioassays, GSK-2881078 had an EC50 of 4.44 x 10^-6 M in the yeast androgen screen and 3.99 x 10^-9 M in a prostate carcinoma cell reporter gene assay, a roughly thousand-fold difference between assay systems for the same molecule.

In the first-in-human study, exposure rose in proportion to dose and the half-life was greater than 100 hours; the abstract gives no exact value. In the phase 1b study, a separate cohort found the effect of CYP3A4 inhibition on PK unlikely to be of clinical significance.

Lean mass was higher than placebo at every dose level in the phase 1b study, and lean body mass increased in the COPD trial. Patient-reported outcomes did not change in the COPD trial.

Two cell assays: EC50 4.44 x 10^-6 M (yeast) versus 3.99 x 10^-9 M (prostate cell reporter)

Cell study

Zierau O et al. J Steroid Biochem Mol Biol. 2019;189:81-86. PMID 30825507.

In two in vitro bioassays, GSK-2881078 had an EC50 of 4.44 x 10^-6 M in the yeast androgen screen and 3.99 x 10^-9 M in a prostate carcinoma cell reporter gene assay, a roughly thousand-fold difference between assay systems for the same molecule. The authors state that, because of their myoanabolic effects, selective androgen receptor modulators are included in the list of prohibited substances and methods of the World Anti-Doping Agency.

Participants / model
Yeast cells and human prostate carcinoma cells in vitro
Treatment
Cell culture exposure; not a therapeutic route
Follow-up
not stated in the source
Study design
Original mechanistic study
Funding
not stated in the source

Cell findings. The anti-doping statement is from a 2019 journal article and is about the SARM class.

Read the original source
First-in-human: 10 men single dose, 65 men and 24 women repeat dose; HDL and SHBG fell

Clinical trial

Clark RV et al. Br J Clin Pharmacol. 2017;83(10):2179-2194. PMID 28449232.

Part A: 10 healthy young men received a single dose of 0 mg, 0.05 mg, 0.1 mg or 0.2 mg or matching placebo. Part B repeat-dose cohorts in men (n=65) were 0.05, 0.2, then 0.08, 0.24, 0.48, 0.75 mg or placebo, and in women (n=24) 0.24 mg, 0.35 mg or placebo, for 7 days at 0.5 mg and 14 days for other doses. Exposure rose in proportion to dose, with a half-life greater than 100 hours. There were no significant effects on vital signs, electrocardiograms, cardiac telemetry or standard clinical laboratory studies. A dose-response effect was observed on lowering both high-density lipoprotein (HDL) and sex hormone-binding globulin (SHBG); in females at 0.35 mg the differences from placebo were -0.518 mmol/L (95% CI -0.703 to -0.334) for HDL and -39.1 nmol/L (95% CI -48.5 to -29.7) for SHBG. Women showed greater sensitivity to these parameters at lower doses than men. Drug-related adverse events were mild. One woman developed a drug rash and was withdrawn. Two men had elevated creatine phosphokinase after physical exertion during follow-up. A serious adverse event occurred in a subject on placebo.

Participants / model
10 healthy young men (single dose); 65 men and 24 women (repeat dose)
Treatment
Oral GSK2881078, 0.05 to 0.75 mg, or placebo
Follow-up
Single dose (Part A); 7 days at 0.5 mg and 14 days for other doses (Part B)
Study design
Original phase 1 trial with placebo
Funding
not stated in the source

Endpoints were PK, vital signs, ECG, telemetry, HDL, SHBG and adverse events. The half-life is given only as greater than 100 hours.

Read the original source
Phase 1b: older men and postmenopausal women, more lean mass than placebo at all doses, no number given

Clinical trial

Neil D et al. J Clin Endocrinol Metab. 2018;103(9):3215-3224. PMID 29982690.

In a randomized, placebo-controlled, parallel-group, repeat-dose, dose-escalation study in healthy older men and postmenopausal women (three cohorts of each), dosing was twice daily for the first 3 days then once daily for up to 53 days, with repeated dual-energy X-ray absorptiometry and MRI cross-sectional thigh scans. Compared with placebo there was greater lean mass accrual at all dose levels, and women had a greater response at lower doses than men. Transient elevations of alanine aminotransferase were observed. No serious adverse events were reported. A separate cohort found the effect of CYP3A4 inhibition on PK unlikely to be of clinical significance. The abstract reports no numeric lean mass change, no kilogram figure and no participant count.

Participants / model
Healthy older men and postmenopausal women
Treatment
Oral GSK2881078 or placebo, twice daily for 3 days then once daily for up to 53 days
Follow-up
Up to 53 days
Study design
Randomized, placebo-controlled, parallel-group, repeat-dose, dose-escalation phase 1b study
Funding
not stated in the source

The abstract gives no lean mass figure, so the page gives none. Endpoints were lean mass by DXA and thigh MRI, PK, ALT and tolerability.

Read the original source
Phase 2A in COPD: 97 patients, 13 weeks, leg-strength 90% intervals crossed zero, patient-reported outcomes unchanged

Randomized controlled trial

Mohan D et al. Thorax. 2023;78(3):258-266. PMID 36283827.

47 postmenopausal women and 50 men with COPD (FEV1 30 to 65% predicted, short physical performance battery 3 to 11) were randomized 1:1 to once-daily placebo or oral GSK2881078 (women 1.0 mg, men 2.0 mg) for 13 weeks with a concurrent home exercise programme of strength training and physical activity. Differences in adjusted mean change from baseline in one-repetition-maximum leg strength versus placebo were, for women, 8.0 kg (90% CI -2.5 to 18.4) and 5.2% (90% CI -4.7 to 15.0); for men, 11.8 kg (90% CI -0.5 to 24.0) and 7.0% (90% CI 0.5 to 13.6). Only the men's percentage result excluded zero, and the intervals are 90%, not 95%. Lean body mass increased, but no changes in patient-reported outcomes were observed. Reversible reductions in HDL cholesterol and transient elevations in hepatic transaminases were the main treatment-related safety findings.

Participants / model
47 postmenopausal women and 50 men with COPD and impaired physical function
Treatment
Oral GSK2881078, 1.0 mg (women) or 2.0 mg (men) once daily, or placebo, with a home exercise programme
Follow-up
13 weeks
Study design
Randomized placebo-controlled phase 2A trial
Funding
not stated in the source

The intervals are 90%, not 95%. Endpoints were leg strength by 1RM, lean body mass, physical function, patient-reported outcomes and safety.

Read the original source

Is it prohibited in sport, and how long can it be detected?

A 2019 paper states that selective androgen receptor modulators are on the World Anti-Doping Agency prohibited list. After a single 760 microgram oral dose, urinary concentration fell to the 2 pg/mL detection limit on day 42.

The authors of a 2019 paper state that, because of their myoanabolic effects, selective androgen receptor modulators are included in the list of prohibited substances and methods of the World Anti-Doping Agency. This page does not establish whether GSK-2881078 is named individually on the current list.

In a human excretion study, a single oral dose of 760 micrograms gave a peak urinary concentration of approximately 920 pg/mL at 8 hours, falling to the detection limit of 2 pg/mL on day 42. After a single oral dose of 1.5 mg, hair concentrations of the intact compound peaked at 1.7 pg/mg in segments collected 3 weeks after administration, declining to 0.7 pg/mg at week 5 and 0.2 pg/mg at week 9. At least four hydroxy metabolites showed similar elimination profiles.

Two cell assays: EC50 4.44 x 10^-6 M (yeast) versus 3.99 x 10^-9 M (prostate cell reporter)

Cell study

Zierau O et al. J Steroid Biochem Mol Biol. 2019;189:81-86. PMID 30825507.

In two in vitro bioassays, GSK-2881078 had an EC50 of 4.44 x 10^-6 M in the yeast androgen screen and 3.99 x 10^-9 M in a prostate carcinoma cell reporter gene assay, a roughly thousand-fold difference between assay systems for the same molecule. The authors state that, because of their myoanabolic effects, selective androgen receptor modulators are included in the list of prohibited substances and methods of the World Anti-Doping Agency.

Participants / model
Yeast cells and human prostate carcinoma cells in vitro
Treatment
Cell culture exposure; not a therapeutic route
Follow-up
not stated in the source
Study design
Original mechanistic study
Funding
not stated in the source

Cell findings. The anti-doping statement is from a 2019 journal article and is about the SARM class.

Read the original source
Excretion study: urine detectable to day 42 after a single 760 microgram dose

Human study

Rading A et al. Drug Test Anal. 2021;13(1):217-222. PMID 33037775.

Following a single oral dose of 760 micrograms, peak urinary concentration was approximately 920 pg/mL at 8 hours, falling to the detection limit of 2 pg/mL on day 42. Following a single oral dose of 1.5 mg, hair concentrations of the intact compound peaked at 1.7 pg/mg in segments collected 3 weeks after administration, declining to 0.7 pg/mg at week 5 and 0.2 pg/mg at week 9. At least four hydroxy metabolites showed similar elimination profiles.

Participants / model
Human volunteers in an excretion study; number not stated in the source
Treatment
Single oral dose, 760 micrograms or 1.5 mg
Follow-up
Urine to day 42; hair to week 9
Study design
Original excretion study
Funding
not stated in the source

An anti-doping detection study, not an efficacy or safety study.

Read the original source

What risks do the studies report?

The first-in-human study reported mild drug-related adverse events, a dose-dependent fall in HDL cholesterol and sex hormone-binding globulin, one drug rash and two men with raised creatine phosphokinase after exertion. Transient transaminase elevations appeared in two studies, and a systematic review reports two rhabdomyolysis cases in a GSK2881078 clinical trial.

In the first-in-human study, a dose-response effect was observed on lowering both HDL cholesterol and sex hormone-binding globulin. In women at 0.35 mg the differences from placebo were -0.518 mmol/L (95% CI -0.703 to -0.334) for HDL and -39.1 nmol/L (95% CI -48.5 to -29.7) for SHBG, and women showed greater sensitivity at lower doses than men. Drug-related adverse events were mild. One woman developed a drug rash and was withdrawn, and two men had elevated creatine phosphokinase after physical exertion during follow-up. A serious adverse event occurred in a subject on placebo.

Transient elevations of alanine aminotransferase were observed in the phase 1b study, which reported no serious adverse events. In the COPD trial, reversible reductions in HDL cholesterol and transient elevations in hepatic transaminases were the main treatment-related safety findings.

A systematic review of SARM safety (33 studies, 2136 patients, 1447 exposed to a SARM, searched 10 November 2022) found drug-induced liver injury in 15 case reports, one Achilles tendon rupture, one rhabdomyolysis and one mild reversible liver enzyme elevation. Elevated alanine aminotransferase was commonly reported in trials, mean 7.1% across trials. Two individuals exposed to GSK2881078 in a clinical trial were reported to have rhabdomyolysis. The authors wrote that recreational SARM use should be strongly discouraged. Most of these class findings are not specific to GSK-2881078.

A PubMed search on 9 October 2026 for GSK2881078 with testosterone, gonadotropin, luteinizing hormone or suppression terms returned 0 records. The only hormone-axis finding located is the dose-dependent fall in sex hormone-binding globulin, a binding protein, not a gonadotropin or a testosterone measurement. No study found reports what GSK-2881078 does to testosterone, LH or FSH in men or women, so nothing here supports a statement about suppression in either direction.

First-in-human: 10 men single dose, 65 men and 24 women repeat dose; HDL and SHBG fell

Clinical trial

Clark RV et al. Br J Clin Pharmacol. 2017;83(10):2179-2194. PMID 28449232.

Part A: 10 healthy young men received a single dose of 0 mg, 0.05 mg, 0.1 mg or 0.2 mg or matching placebo. Part B repeat-dose cohorts in men (n=65) were 0.05, 0.2, then 0.08, 0.24, 0.48, 0.75 mg or placebo, and in women (n=24) 0.24 mg, 0.35 mg or placebo, for 7 days at 0.5 mg and 14 days for other doses. Exposure rose in proportion to dose, with a half-life greater than 100 hours. There were no significant effects on vital signs, electrocardiograms, cardiac telemetry or standard clinical laboratory studies. A dose-response effect was observed on lowering both high-density lipoprotein (HDL) and sex hormone-binding globulin (SHBG); in females at 0.35 mg the differences from placebo were -0.518 mmol/L (95% CI -0.703 to -0.334) for HDL and -39.1 nmol/L (95% CI -48.5 to -29.7) for SHBG. Women showed greater sensitivity to these parameters at lower doses than men. Drug-related adverse events were mild. One woman developed a drug rash and was withdrawn. Two men had elevated creatine phosphokinase after physical exertion during follow-up. A serious adverse event occurred in a subject on placebo.

Participants / model
10 healthy young men (single dose); 65 men and 24 women (repeat dose)
Treatment
Oral GSK2881078, 0.05 to 0.75 mg, or placebo
Follow-up
Single dose (Part A); 7 days at 0.5 mg and 14 days for other doses (Part B)
Study design
Original phase 1 trial with placebo
Funding
not stated in the source

Endpoints were PK, vital signs, ECG, telemetry, HDL, SHBG and adverse events. The half-life is given only as greater than 100 hours.

Read the original source
Phase 1b: older men and postmenopausal women, more lean mass than placebo at all doses, no number given

Clinical trial

Neil D et al. J Clin Endocrinol Metab. 2018;103(9):3215-3224. PMID 29982690.

In a randomized, placebo-controlled, parallel-group, repeat-dose, dose-escalation study in healthy older men and postmenopausal women (three cohorts of each), dosing was twice daily for the first 3 days then once daily for up to 53 days, with repeated dual-energy X-ray absorptiometry and MRI cross-sectional thigh scans. Compared with placebo there was greater lean mass accrual at all dose levels, and women had a greater response at lower doses than men. Transient elevations of alanine aminotransferase were observed. No serious adverse events were reported. A separate cohort found the effect of CYP3A4 inhibition on PK unlikely to be of clinical significance. The abstract reports no numeric lean mass change, no kilogram figure and no participant count.

Participants / model
Healthy older men and postmenopausal women
Treatment
Oral GSK2881078 or placebo, twice daily for 3 days then once daily for up to 53 days
Follow-up
Up to 53 days
Study design
Randomized, placebo-controlled, parallel-group, repeat-dose, dose-escalation phase 1b study
Funding
not stated in the source

The abstract gives no lean mass figure, so the page gives none. Endpoints were lean mass by DXA and thigh MRI, PK, ALT and tolerability.

Read the original source
Phase 2A in COPD: 97 patients, 13 weeks, leg-strength 90% intervals crossed zero, patient-reported outcomes unchanged

Randomized controlled trial

Mohan D et al. Thorax. 2023;78(3):258-266. PMID 36283827.

47 postmenopausal women and 50 men with COPD (FEV1 30 to 65% predicted, short physical performance battery 3 to 11) were randomized 1:1 to once-daily placebo or oral GSK2881078 (women 1.0 mg, men 2.0 mg) for 13 weeks with a concurrent home exercise programme of strength training and physical activity. Differences in adjusted mean change from baseline in one-repetition-maximum leg strength versus placebo were, for women, 8.0 kg (90% CI -2.5 to 18.4) and 5.2% (90% CI -4.7 to 15.0); for men, 11.8 kg (90% CI -0.5 to 24.0) and 7.0% (90% CI 0.5 to 13.6). Only the men's percentage result excluded zero, and the intervals are 90%, not 95%. Lean body mass increased, but no changes in patient-reported outcomes were observed. Reversible reductions in HDL cholesterol and transient elevations in hepatic transaminases were the main treatment-related safety findings.

Participants / model
47 postmenopausal women and 50 men with COPD and impaired physical function
Treatment
Oral GSK2881078, 1.0 mg (women) or 2.0 mg (men) once daily, or placebo, with a home exercise programme
Follow-up
13 weeks
Study design
Randomized placebo-controlled phase 2A trial
Funding
not stated in the source

The intervals are 90%, not 95%. Endpoints were leg strength by 1RM, lean body mass, physical function, patient-reported outcomes and safety.

Read the original source
SARM safety review: 33 studies, 2136 patients, liver injury cases, two rhabdomyolysis cases with GSK2881078

Systematic review and meta-analysis

Vignali JD et al. J Xenobiot. 2023;13(2):218-236. PMID 37218811.

A systematic review searched PubMed, Scopus, Web of Science and ClinicalTrials.gov on 10 November 2022 and included 33 studies: 15 case reports or case series and 18 clinical trials, total 2136 patients with 1447 exposed to a SARM. Case reports covered drug-induced liver injury (n=15), Achilles tendon rupture (n=1), rhabdomyolysis (n=1) and mild reversible liver enzyme elevation (n=1). Elevated alanine aminotransferase was commonly reported in trials, mean 7.1% across trials. Two individuals exposed to GSK2881078 in a clinical trial were reported to have rhabdomyolysis. The authors wrote that recreational SARM use should be strongly discouraged.

Participants / model
2136 patients across 33 studies, 1447 exposed to a SARM; recreational users in the case reports
Treatment
Oral SARMs, various
Follow-up
Studies searched to 10 November 2022
Study design
Systematic review of case reports and clinical trials
Funding
not stated in the source

Class-level findings across many SARMs. Only the two rhabdomyolysis cases are GSK2881078-specific.

Read the original source
PubMed search, 9 October 2026: 0 records on testosterone, LH or suppression

PubMed search record

PubMed search run on 9 October 2026: GSK2881078 AND (testosterone OR gonadotropin OR "luteinizing hormone" OR suppression). 0 records returned.

The search returned 0 records. The only hormone-axis finding located in any GSK-2881078 study is the dose-dependent fall in sex hormone-binding globulin in the phase 1 trial, which is a binding protein, not a gonadotropin or a testosterone measurement. In the records reviewed, no study reports what GSK-2881078 does to testosterone, LH or FSH in men or women, so no claim about suppression or its absence can be made from them.

Participants / model
Records returned, not a population
Treatment
Not applicable
Follow-up
Search run on 9 October 2026
Study design
Literature search
Funding
not stated in the source

A search result shows what PubMed returned on that date. It is not proof that no unindexed study exists.

Read the original source

Why does GSK-2881078 sit in C tier?

A real mechanism and a lean-mass signal in early studies support the C. The data are thin: one efficacy study in 97 patients, no registered phase 3 study, and patient-reported outcomes that did not change.

Lean mass was higher than placebo at every dose level in the phase 1b study, and lean body mass increased in the COPD trial. The limits are the amount of data and what it shows about the patient: in the COPD trial, the 90% intervals for leg strength crossed zero for women on both measures and for men on the kilogram measure, and patient-reported outcomes did not change. That keeps the grade below B.

It stays above D because nothing failed outright and no serious adverse event was attributed to the drug in either phase 1 study. Nothing newer than the 2023 COPD report appears in the records reviewed.

Phase 1b: older men and postmenopausal women, more lean mass than placebo at all doses, no number given

Clinical trial

Neil D et al. J Clin Endocrinol Metab. 2018;103(9):3215-3224. PMID 29982690.

In a randomized, placebo-controlled, parallel-group, repeat-dose, dose-escalation study in healthy older men and postmenopausal women (three cohorts of each), dosing was twice daily for the first 3 days then once daily for up to 53 days, with repeated dual-energy X-ray absorptiometry and MRI cross-sectional thigh scans. Compared with placebo there was greater lean mass accrual at all dose levels, and women had a greater response at lower doses than men. Transient elevations of alanine aminotransferase were observed. No serious adverse events were reported. A separate cohort found the effect of CYP3A4 inhibition on PK unlikely to be of clinical significance. The abstract reports no numeric lean mass change, no kilogram figure and no participant count.

Participants / model
Healthy older men and postmenopausal women
Treatment
Oral GSK2881078 or placebo, twice daily for 3 days then once daily for up to 53 days
Follow-up
Up to 53 days
Study design
Randomized, placebo-controlled, parallel-group, repeat-dose, dose-escalation phase 1b study
Funding
not stated in the source

The abstract gives no lean mass figure, so the page gives none. Endpoints were lean mass by DXA and thigh MRI, PK, ALT and tolerability.

Read the original source
Phase 2A in COPD: 97 patients, 13 weeks, leg-strength 90% intervals crossed zero, patient-reported outcomes unchanged

Randomized controlled trial

Mohan D et al. Thorax. 2023;78(3):258-266. PMID 36283827.

47 postmenopausal women and 50 men with COPD (FEV1 30 to 65% predicted, short physical performance battery 3 to 11) were randomized 1:1 to once-daily placebo or oral GSK2881078 (women 1.0 mg, men 2.0 mg) for 13 weeks with a concurrent home exercise programme of strength training and physical activity. Differences in adjusted mean change from baseline in one-repetition-maximum leg strength versus placebo were, for women, 8.0 kg (90% CI -2.5 to 18.4) and 5.2% (90% CI -4.7 to 15.0); for men, 11.8 kg (90% CI -0.5 to 24.0) and 7.0% (90% CI 0.5 to 13.6). Only the men's percentage result excluded zero, and the intervals are 90%, not 95%. Lean body mass increased, but no changes in patient-reported outcomes were observed. Reversible reductions in HDL cholesterol and transient elevations in hepatic transaminases were the main treatment-related safety findings.

Participants / model
47 postmenopausal women and 50 men with COPD and impaired physical function
Treatment
Oral GSK2881078, 1.0 mg (women) or 2.0 mg (men) once daily, or placebo, with a home exercise programme
Follow-up
13 weeks
Study design
Randomized placebo-controlled phase 2A trial
Funding
not stated in the source

The intervals are 90%, not 95%. Endpoints were leg strength by 1RM, lean body mass, physical function, patient-reported outcomes and safety.

Read the original source
Registry, 9 October 2026: three studies (99, 108 and 97 participants); two have no posted results

Trial registry record

ClinicalTrials.gov query for GSK2881078 run on 9 October 2026; records NCT02045940, NCT02567773 and NCT03359473.

A ClinicalTrials.gov query on 9 October 2026 returned three studies: NCT02045940 (phase 1, n=99, completed, no results posted), NCT02567773 (phase 1, n=108, completed, no results posted) and NCT03359473 (phase 2, n=97, completed, results posted). No study beyond phase 2 is registered. The two phase 1 records without posted results show that studies were run, not efficacy or safety.

Participants / model
Records returned, not a population
Treatment
Not applicable
Follow-up
Query run on 9 October 2026
Study design
Registry query
Funding
not stated in the source

The link opens the phase 2 record, NCT03359473, which has posted results.

Read the original source
First-in-human: 10 men single dose, 65 men and 24 women repeat dose; HDL and SHBG fell

Clinical trial

Clark RV et al. Br J Clin Pharmacol. 2017;83(10):2179-2194. PMID 28449232.

Part A: 10 healthy young men received a single dose of 0 mg, 0.05 mg, 0.1 mg or 0.2 mg or matching placebo. Part B repeat-dose cohorts in men (n=65) were 0.05, 0.2, then 0.08, 0.24, 0.48, 0.75 mg or placebo, and in women (n=24) 0.24 mg, 0.35 mg or placebo, for 7 days at 0.5 mg and 14 days for other doses. Exposure rose in proportion to dose, with a half-life greater than 100 hours. There were no significant effects on vital signs, electrocardiograms, cardiac telemetry or standard clinical laboratory studies. A dose-response effect was observed on lowering both high-density lipoprotein (HDL) and sex hormone-binding globulin (SHBG); in females at 0.35 mg the differences from placebo were -0.518 mmol/L (95% CI -0.703 to -0.334) for HDL and -39.1 nmol/L (95% CI -48.5 to -29.7) for SHBG. Women showed greater sensitivity to these parameters at lower doses than men. Drug-related adverse events were mild. One woman developed a drug rash and was withdrawn. Two men had elevated creatine phosphokinase after physical exertion during follow-up. A serious adverse event occurred in a subject on placebo.

Participants / model
10 healthy young men (single dose); 65 men and 24 women (repeat dose)
Treatment
Oral GSK2881078, 0.05 to 0.75 mg, or placebo
Follow-up
Single dose (Part A); 7 days at 0.5 mg and 14 days for other doses (Part B)
Study design
Original phase 1 trial with placebo
Funding
not stated in the source

Endpoints were PK, vital signs, ECG, telemetry, HDL, SHBG and adverse events. The half-life is given only as greater than 100 hours.

Read the original source

Studies and sources

PubChem CID 86709174: C14H13F3N2O2S, 330.33 g/mol, single defined enantiomer

Chemical identity record

National Library of Medicine. PubChem compound record CID 86709174 (GSK-2881078).

GSK-2881078: PubChem CID 86709174, C14H13F3N2O2S, 330.33 g/mol, CAS 1539314-06-1. The record resolves to a single defined enantiomer, 1-[(2R)-1-methylsulfonylpropan-2-yl]-4-(trifluoromethyl)indole-5-carbonitrile. Listed synonyms include GSK2881078 and GSK 2881078. There is no salt form and no marketed product, so a vendor powder has no reference standard to be compared against.

Participants / model
Chemical identity, not a clinical population
Treatment
Defined molecule, no approved formulation
Follow-up
Not applicable
Study design
NLM chemical record
Funding
not stated in the source

Identity record only; it says nothing about efficacy or safety.

Read the original source
First-in-human: 10 men single dose, 65 men and 24 women repeat dose; HDL and SHBG fell

Clinical trial

Clark RV et al. Br J Clin Pharmacol. 2017;83(10):2179-2194. PMID 28449232.

Part A: 10 healthy young men received a single dose of 0 mg, 0.05 mg, 0.1 mg or 0.2 mg or matching placebo. Part B repeat-dose cohorts in men (n=65) were 0.05, 0.2, then 0.08, 0.24, 0.48, 0.75 mg or placebo, and in women (n=24) 0.24 mg, 0.35 mg or placebo, for 7 days at 0.5 mg and 14 days for other doses. Exposure rose in proportion to dose, with a half-life greater than 100 hours. There were no significant effects on vital signs, electrocardiograms, cardiac telemetry or standard clinical laboratory studies. A dose-response effect was observed on lowering both high-density lipoprotein (HDL) and sex hormone-binding globulin (SHBG); in females at 0.35 mg the differences from placebo were -0.518 mmol/L (95% CI -0.703 to -0.334) for HDL and -39.1 nmol/L (95% CI -48.5 to -29.7) for SHBG. Women showed greater sensitivity to these parameters at lower doses than men. Drug-related adverse events were mild. One woman developed a drug rash and was withdrawn. Two men had elevated creatine phosphokinase after physical exertion during follow-up. A serious adverse event occurred in a subject on placebo.

Participants / model
10 healthy young men (single dose); 65 men and 24 women (repeat dose)
Treatment
Oral GSK2881078, 0.05 to 0.75 mg, or placebo
Follow-up
Single dose (Part A); 7 days at 0.5 mg and 14 days for other doses (Part B)
Study design
Original phase 1 trial with placebo
Funding
not stated in the source

Endpoints were PK, vital signs, ECG, telemetry, HDL, SHBG and adverse events. The half-life is given only as greater than 100 hours.

Read the original source
Phase 1b: older men and postmenopausal women, more lean mass than placebo at all doses, no number given

Clinical trial

Neil D et al. J Clin Endocrinol Metab. 2018;103(9):3215-3224. PMID 29982690.

In a randomized, placebo-controlled, parallel-group, repeat-dose, dose-escalation study in healthy older men and postmenopausal women (three cohorts of each), dosing was twice daily for the first 3 days then once daily for up to 53 days, with repeated dual-energy X-ray absorptiometry and MRI cross-sectional thigh scans. Compared with placebo there was greater lean mass accrual at all dose levels, and women had a greater response at lower doses than men. Transient elevations of alanine aminotransferase were observed. No serious adverse events were reported. A separate cohort found the effect of CYP3A4 inhibition on PK unlikely to be of clinical significance. The abstract reports no numeric lean mass change, no kilogram figure and no participant count.

Participants / model
Healthy older men and postmenopausal women
Treatment
Oral GSK2881078 or placebo, twice daily for 3 days then once daily for up to 53 days
Follow-up
Up to 53 days
Study design
Randomized, placebo-controlled, parallel-group, repeat-dose, dose-escalation phase 1b study
Funding
not stated in the source

The abstract gives no lean mass figure, so the page gives none. Endpoints were lean mass by DXA and thigh MRI, PK, ALT and tolerability.

Read the original source
Phase 2A in COPD: 97 patients, 13 weeks, leg-strength 90% intervals crossed zero, patient-reported outcomes unchanged

Randomized controlled trial

Mohan D et al. Thorax. 2023;78(3):258-266. PMID 36283827.

47 postmenopausal women and 50 men with COPD (FEV1 30 to 65% predicted, short physical performance battery 3 to 11) were randomized 1:1 to once-daily placebo or oral GSK2881078 (women 1.0 mg, men 2.0 mg) for 13 weeks with a concurrent home exercise programme of strength training and physical activity. Differences in adjusted mean change from baseline in one-repetition-maximum leg strength versus placebo were, for women, 8.0 kg (90% CI -2.5 to 18.4) and 5.2% (90% CI -4.7 to 15.0); for men, 11.8 kg (90% CI -0.5 to 24.0) and 7.0% (90% CI 0.5 to 13.6). Only the men's percentage result excluded zero, and the intervals are 90%, not 95%. Lean body mass increased, but no changes in patient-reported outcomes were observed. Reversible reductions in HDL cholesterol and transient elevations in hepatic transaminases were the main treatment-related safety findings.

Participants / model
47 postmenopausal women and 50 men with COPD and impaired physical function
Treatment
Oral GSK2881078, 1.0 mg (women) or 2.0 mg (men) once daily, or placebo, with a home exercise programme
Follow-up
13 weeks
Study design
Randomized placebo-controlled phase 2A trial
Funding
not stated in the source

The intervals are 90%, not 95%. Endpoints were leg strength by 1RM, lean body mass, physical function, patient-reported outcomes and safety.

Read the original source
Registry, 9 October 2026: three studies (99, 108 and 97 participants); two have no posted results

Trial registry record

ClinicalTrials.gov query for GSK2881078 run on 9 October 2026; records NCT02045940, NCT02567773 and NCT03359473.

A ClinicalTrials.gov query on 9 October 2026 returned three studies: NCT02045940 (phase 1, n=99, completed, no results posted), NCT02567773 (phase 1, n=108, completed, no results posted) and NCT03359473 (phase 2, n=97, completed, results posted). No study beyond phase 2 is registered. The two phase 1 records without posted results show that studies were run, not efficacy or safety.

Participants / model
Records returned, not a population
Treatment
Not applicable
Follow-up
Query run on 9 October 2026
Study design
Registry query
Funding
not stated in the source

The link opens the phase 2 record, NCT03359473, which has posted results.

Read the original source
SARM safety review: 33 studies, 2136 patients, liver injury cases, two rhabdomyolysis cases with GSK2881078

Systematic review and meta-analysis

Vignali JD et al. J Xenobiot. 2023;13(2):218-236. PMID 37218811.

A systematic review searched PubMed, Scopus, Web of Science and ClinicalTrials.gov on 10 November 2022 and included 33 studies: 15 case reports or case series and 18 clinical trials, total 2136 patients with 1447 exposed to a SARM. Case reports covered drug-induced liver injury (n=15), Achilles tendon rupture (n=1), rhabdomyolysis (n=1) and mild reversible liver enzyme elevation (n=1). Elevated alanine aminotransferase was commonly reported in trials, mean 7.1% across trials. Two individuals exposed to GSK2881078 in a clinical trial were reported to have rhabdomyolysis. The authors wrote that recreational SARM use should be strongly discouraged.

Participants / model
2136 patients across 33 studies, 1447 exposed to a SARM; recreational users in the case reports
Treatment
Oral SARMs, various
Follow-up
Studies searched to 10 November 2022
Study design
Systematic review of case reports and clinical trials
Funding
not stated in the source

Class-level findings across many SARMs. Only the two rhabdomyolysis cases are GSK2881078-specific.

Read the original source
SARM class review: 9 trials, 970 patients, six SARMs, pooled before-and-after means

Systematic review and meta-analysis

Wen J et al. Clin Endocrinol (Oxf). 2025;102(1):3-27. PMID 39285652.

The review included 9 studies and 970 patients, mean age 57.1 years (range 35.3 to 75.9) and mean follow-up 80 days (range 14 to 180), covering six SARMs including GSK2881078. Mean lean body mass went from 49.46 kg before the intervention to 50.86 kg after, and mean fat mass from 21.99 kg to 21.85 kg. Mean stair climbing power fell from 352.24 W to 315.16 W, while mean one-repetition-maximum leg press rose from 1822.77 N to 2191.27 N.

Participants / model
970 patients across 9 randomized trials, mean age 57.1
Treatment
Six different SARMs, oral
Follow-up
Mean follow-up 80 days (range 14 to 180)
Study design
Systematic review of randomized trials
Funding
not stated in the source

These are pooled before-and-after means across six different molecules, not placebo-controlled effect sizes for GSK-2881078.

Read the original source
Two cell assays: EC50 4.44 x 10^-6 M (yeast) versus 3.99 x 10^-9 M (prostate cell reporter)

Cell study

Zierau O et al. J Steroid Biochem Mol Biol. 2019;189:81-86. PMID 30825507.

In two in vitro bioassays, GSK-2881078 had an EC50 of 4.44 x 10^-6 M in the yeast androgen screen and 3.99 x 10^-9 M in a prostate carcinoma cell reporter gene assay, a roughly thousand-fold difference between assay systems for the same molecule. The authors state that, because of their myoanabolic effects, selective androgen receptor modulators are included in the list of prohibited substances and methods of the World Anti-Doping Agency.

Participants / model
Yeast cells and human prostate carcinoma cells in vitro
Treatment
Cell culture exposure; not a therapeutic route
Follow-up
not stated in the source
Study design
Original mechanistic study
Funding
not stated in the source

Cell findings. The anti-doping statement is from a 2019 journal article and is about the SARM class.

Read the original source
Excretion study: urine detectable to day 42 after a single 760 microgram dose

Human study

Rading A et al. Drug Test Anal. 2021;13(1):217-222. PMID 33037775.

Following a single oral dose of 760 micrograms, peak urinary concentration was approximately 920 pg/mL at 8 hours, falling to the detection limit of 2 pg/mL on day 42. Following a single oral dose of 1.5 mg, hair concentrations of the intact compound peaked at 1.7 pg/mg in segments collected 3 weeks after administration, declining to 0.7 pg/mg at week 5 and 0.2 pg/mg at week 9. At least four hydroxy metabolites showed similar elimination profiles.

Participants / model
Human volunteers in an excretion study; number not stated in the source
Treatment
Single oral dose, 760 micrograms or 1.5 mg
Follow-up
Urine to day 42; hair to week 9
Study design
Original excretion study
Funding
not stated in the source

An anti-doping detection study, not an efficacy or safety study.

Read the original source

Why is GSK-2881078 in C tier?

C fits a compound with a real mechanism and a lean-mass signal in early studies but thin data: one efficacy study in 97 patients, no registered phase 3 study, and nothing newer than the 2023 COPD report in the records found. That study's 90% intervals for leg strength crossed zero for women on both measures and for men on the kilogram measure, and patient-reported outcomes did not change. It stays above D because nothing failed outright and no serious adverse event was attributed to the drug in either phase 1 study.