A Phase 2 interventional study of FISH OIL 500MG OMEGA-3 SOFT GEL MINIS and Placebo in Dermatomyositis (DM) and Juvenile Dermatomyositis (JDM), sponsored by National Institute of Environmental Health Sciences (NIEHS). Recruiting at 1 site in United States. Open to participants aged 18 Years to 62 Years. Per ClinicalTrials.gov, last updated 2026-11-10.
Sponsored by National Institute of Environmental Health Sciences (NIEHS) · Phase 2, Interventional, and Treatment
Dermatomyositis (DM) is a rare autoimmune disease that causes muscle weakness, skin rashes, and other symptoms. Researchers think both genetic and environmental factors play a role in this disease. They want to find out more about how diet and lifestyle choices affect people with DM/JDM.
Objective:
To see if omega-3 fatty acid supplements from fish oil, combined with a healthy diet, can help people with DM/JDM.
Eligibility:
Adults 18-62 years old, who live in the United States, can read English, and access Internet to complete questionnaires can participate.
Design:
Participants will have 5 or 6 inpatient visits. For 5 visits they may need to stay in the Clinical Center for up to 5 days. Participants will be screened. They will have a physical exam with blood, urine and stool tests. They will have tests of their heart and lung function. Their muscle strength will be measured. They may have an imaging scan of their thighs and pelvis. They will complete online questionnaires about their health and lifestyle. They may complete two optional skin biopsies. Participants will take 4 small capsules by mouth twice a day for up to 6 months. The capsules will contain omega-3 fatty acids from fish oil or a placebo. The placebo looks just like the regular capsule but contains no active ingredients. Participants will not know which capsules they are taking. They will follow a healthy diet based on the General Healthy Eating Pattern.
Participants will receive dietary coaching and will have virtual check-ins throughout the study. For two 7-day periods, they will wear a watch-like device to track their daily activity and sleep patterns. Participants may opt to remain in the study for an additional 12 weeks. All will receive the fish oil supplements during this stage.
Study Description:
Multi-site, randomized, double-blind, placebo-controlled trial to evaluate the efficacy of O3FA supplementation on improving myositis disease activity, including muscle strength and function and other elements of disease activity, and quality of life in patients with mild to moderately active Dermatomyositis (DM)/Juvenile Dermatomyositis (JDM).
Objectives:
Primary Objective:
-To examine the effect of O3FA supplementation on disease activity in a randomized, placebo-controlled trial in patients with mild to moderately active DM/JDM.
Secondary Objectives:
Exploratory Objectives:
Endpoints:
Primary:
Reduction in DM/JDM disease activity, as assessed by the American College of Rheumatology/European League Against Rheumatism (ACR EULAR) Myositis Response Criteria Total Improvement Score (TIS) 2016 a composite of change in myositis core set activity measures, from Week 0 to Week 24.
Secondary:
Minimum improvement, as defined by ACR EULAR Myositis Response Criteria (i.e., improvement >= 20 points in the TIS) and change in core set measures of myositis disease activity between week 0 and week 24 and between weeks 0 and 12. Frequency of adverse events (AE) in O3FA vs. Placebo group from week 0 to 24.
184 studies on the registry are indexed under Dermatomyositis; 63 are open to participants now.
This study's planned enrollment of 3,000 is above the median of 35 across 130 interventional studies indexed under Dermatomyositis.
Browse Dermatomyositis studies →National Institute of Environmental Health Sciences (NIEHS) is the lead sponsor of 183 studies on the registry; 18 are open to participants now.
Counted across the registry records on this site, refreshed daily.
The criteria were revised on the registry on Oct 30, 2026. See what changed
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
In order to be eligible to participate in this study, an individual must meet all of the following criteria:
Moderately active DM/JDM defined by:
At least 2 of the following criteria:
If an immunosuppressive agent was discontinued prior to the screening visit, then there must be a before week -6 visit:
For discontinuation of biologic or targeted drug therapies or dietary supplements, a washout prior to visit 1 (week -6) is required of 4 terminal half-lives.
Half-lives of most common biologics and targeted drug therapies used in the treatment of DM/JDM:
EXCLUSION CRITERIA:
An individual who meets any of the following criteria will be excluded from participation in this study:
Myositis in overlap with another disease will be excluded under the following conditions:
i. Myositis overlapping with another autoimmune disease that precludes accurate assessment of treatment response (e.g., difficulty assessing muscle strength in a patient with scleroderma and associated myositis).
ii. Myositis overlapping with inflammatory bowel disease (IBD), including Crohn's disease, ulcerative colitis, or celiac disease, unless stable and well controlled with no changes in IBD-related medications for at least 3 months prior to enrollment, in which case the patient may be included.
iii. Myositis overlapping with autoimmune thyroid disease (e.g., Hashimoto's disease or Graves' disease), unless the thyroid disease is
stable and well controlled with no changes in thyroid-related medications for at least 3 months prior to enrollment, in which case the
patient may be included.
Concomitant illness that would prevent adequate patient assessment or in the investigators' opinion pose an added risk for study participants. The investigator may consider further evaluation or consultation if clinically indicated prior to study enrollment:
History of , however, the following would be allowable into the study:
Participants with any of the following:
Currently taking supplements or medications that affect lipoproteins. For discontinuation of lipoprotein drug therapies or dietary supplements, a prior to visit 1 (week -6) is required of 4 terminal halflives:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Two enzymes measured in a routine blood test of the liver. Higher levels can mean the liver is under strain or damaged. SGPT and SGOT are older names for ALT and AST.
Criteria usually give a limit as a multiple of the upper limit of normal (ULN), often higher when cancer has spread to the liver.
The top of the normal range for a blood test, as set by the laboratory that runs it. Each lab prints its own range next to your result.
“≤ 2.5 × ULN” means the result can be up to two and a half times that top value.
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
A planned gap after a treatment, so that its effects can lessen before the study treatment or a study assessment. Ask the study team and the doctor who prescribed it before changing any medicine.
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
A condition in which the immune system attacks the body’s own tissues, such as rheumatoid arthritis, lupus, psoriasis, type 1 diabetes or inflammatory bowel disease.
Immunotherapy studies often leave out active autoimmune disease, and some name exceptions, such as thyroid disease on replacement hormone. Check the exceptions this study lists.
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
Hepatitis B is a virus that infects the liver. These are separate tests: HBsAg positive usually means a current infection (a recent vaccination can briefly cause it too); total anti-HBc (HBcAb) positive means an infection now or in the past; HBV DNA measures how much virus is in the blood.
Some studies accept a past infection if HBV DNA is undetectable, sometimes with antiviral medicine during the study. Check what this study allows.
Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.
The New York Heart Association’s four classes of how much heart failure limits physical activity.
Studies set their own limit — many outside heart failure leave out class III–IV, while heart failure studies may ask for a particular class. Check the class this study names.
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
GFR (glomerular filtration rate) is how much blood the kidneys filter each minute. It is usually estimated from a blood test — eGFR, by formulas such as CKD-EPI or MDRD — and some studies ask for it to be measured directly instead. Usually given in mL/min/1.73 m².
Check the method, the units and the minimum the study states. A value of 90 or above is in the normal-or-high range, but kidney damage can show in other tests too.
Blood cells that help blood clot. Too few raises the risk of bleeding and bruising. A usual adult range is about 150–400 × 10⁹/L (150,000–400,000 per µL); each lab has its own reference range.
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
The other ingredients in a medicine besides the active drug, such as fillers, colours or preservatives.
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
The protein in red blood cells that carries oxygen. A low level is anaemia, which can cause tiredness and breathlessness. Measured in g/dL or g/L (9 g/dL is 90 g/L).
ALT and AST (liver enzymes)
Two enzymes measured in a routine blood test of the liver. Higher levels can mean the liver is under strain or damaged. SGPT and SGOT are older names for ALT and AST.
Criteria usually give a limit as a multiple of the upper limit of normal (ULN), often higher when cancer has spread to the liver.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ULN (upper limit of normal)
The top of the normal range for a blood test, as set by the laboratory that runs it. Each lab prints its own range next to your result.
“≤ 2.5 × ULN” means the result can be up to two and a half times that top value.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Corticosteroids (steroids)
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Immunosuppression
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Washout period
A planned gap after a treatment, so that its effects can lessen before the study treatment or a study assessment. Ask the study team and the doctor who prescribed it before changing any medicine.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
BMI (body mass index)
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Autoimmune disease
A condition in which the immune system attacks the body’s own tissues, such as rheumatoid arthritis, lupus, psoriasis, type 1 diabetes or inflammatory bowel disease.
Immunotherapy studies often leave out active autoimmune disease, and some name exceptions, such as thyroid disease on replacement hormone. Check the exceptions this study lists.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
HIV
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hepatitis B tests
Hepatitis B is a virus that infects the liver. These are separate tests: HBsAg positive usually means a current infection (a recent vaccination can briefly cause it too); total anti-HBc (HBcAb) positive means an infection now or in the past; HBV DNA measures how much virus is in the blood.
Some studies accept a past infection if HBV DNA is undetectable, sometimes with antiviral medicine during the study. Check what this study allows.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Clinically significant
Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
NYHA class (heart failure)
The New York Heart Association’s four classes of how much heart failure limits physical activity.
Studies set their own limit — many outside heart failure leave out class III–IV, while heart failure studies may ask for a particular class. Check the class this study names.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Cancer (malignancy)
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
GFR and eGFR (kidney filtering)
GFR (glomerular filtration rate) is how much blood the kidneys filter each minute. It is usually estimated from a blood test — eGFR, by formulas such as CKD-EPI or MDRD — and some studies ask for it to be measured directly instead. Usually given in mL/min/1.73 m².
Check the method, the units and the minimum the study states. A value of 90 or above is in the normal-or-high range, but kidney damage can show in other tests too.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Platelets
Blood cells that help blood clot. Too few raises the risk of bleeding and bruising. A usual adult range is about 150–400 × 10⁹/L (150,000–400,000 per µL); each lab has its own reference range.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraindication
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Excipients
The other ingredients in a medicine besides the active drug, such as fillers, colours or preservatives.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hypersensitivity
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hemoglobin (Hb)
The protein in red blood cells that carries oxygen. A low level is anaemia, which can cause tiredness and breathlessness. Measured in g/dL or g/L (9 g/dL is 90 g/L).
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Fish oil supplement and healthy diet
Dietary Supplement: FISH OIL 500MG OMEGA-3 SOFT GEL MINIS
Placebo capsules look identical to fish oil but contain corn oil, complemented by healthy diet
Dietary Supplement: Placebo
Translucent, light yellow, oblong soft gelatin capsule containing a straw to amber light liquid.
Placebo capsules look identical to fish oil but contain corn oil, complemented by healthy diet
Reduction in DM/JDM disease activity, as assessed by the ACR EULAR Myositis Response Criteria Total Improvement Score, a composite assessment of change in myositis core set activity measures, between the O3FA vs. placebo groups.
Assessed at 24 weeks for the treatment arm (O3FA) and the placebo arm.
Time frame: From Week 0 to Week 24
Meeting minimum clinical improvement in disease activity in O3FA and placebo groups
Minimum clinical improvement defined by ACR EULAR myositis response criteria: improvement of \>= 20 points in the Total Improvement Score (TIS) between the O3FA vs. placebo groups at Week 24
Time frame: From Week 0 to Week 24
The effects of O3FA on DM/JDM disease activity
Change in myositis disease activity as assessed by specific core set disease activity measures between the O3FA vs. placebo groups
Time frame: From Week 0 to Week 24
Safety and Tolerability
Incidence of adverse events by NCI CTC Adverse Event assessments between the O3FA vs. placebo groups.
Time frame: From Week 0 to Week 24
Plan to share: No — Participants will be enrolled from a rare disease population, and there is a risk of deidentifying the data.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
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Studies of the drug tested here: Fish Oils
National Institute of Environmental Health Sciences (NIEHS) →