A Phase 1/2 interventional study of MSC-KI-PL-204 in Hoarseness, Dysphonia and Aphonia, sponsored by Karolinska University Hospital. Completed at 1 site in Sweden. Open to participants aged 18 Years to 65 Years. Per ClinicalTrials.gov, last updated 2026-01-27.
Sponsored by Karolinska University Hospital · Phase 1/2, Interventional, and Treatment
The overall aim of the project is to develop a new method for treatment of untreatable severe hoarseness due to vocal fold scarring by local injection of autologous mesenchymal stromal cells (MSC). At present there is no lasting effective treatment for this condition which results in personal suffering, and often extended sick leave, change of work or unemployement for the patients.
Based on the previous results the investigators expect the autologous MSC product KI-MSC-PL-204 to be a new effective treatment without side effects for many patients with severe hoarseness or aphonia due to vocal fold scarring.
The general aim of the project is to develop a treatment for severe hoarseness due to vocal fold (VF) scarring. Vocal fold scarring can be caused by tumor surgery, radiotherapy, severe inflammation or is early acquired (sulcus vocalis with scar) and results in stiff vocal folds with decreased vibratory capacity and severe deterioration or total loss of voice (aphonia). There is no lasting effective treatment. Bone marrow derived mesenchymal stem cells (MSC) are immunomodulatory, decrease inflammation and improve endogenous healing. After receiving ethical permission the investigators have since 2012 treated 16 patients with manifest vocal fold scarring and severe hoarseness by scar resection and local injection of autologous bone marrow MSC to restore speech. This project was the first in the world to study the effects of MSC treatment of vocal fold scarring in humans. Analysis was made before and up to 12 months post operatively with voice recordings, examination with high speed camera and elasticity measurements of the vocal folds with novel technology. No side effects were found for any patient and for two thirds of the patients with 12 months follow-up the vocal fold function improved and no patient deteriorated.
While cell therapy with autologous MSC was classified according to the Tissue Legislation before 2015, it is now regarded as drug treatment. In accordance with this legislation, the MSC production is now full scale GMP. The investigators have recently received permissions from Swedish Medical Product Agency (DNr 5.1-2019-92069) and from the Regional ethic committee (Drn 2019-06160) for an open Phase I/Il study in patients with severe dysphonia and vocal fold scarring to evaluate safety, tolerability and vocal function after surgery with local administration of autologous mesenchymal stromal cell product KI-MSC-PL-204 as an extended study on 15 patients.
MSC may in the future be used to treat patients with severe hoarseness due to scarring, as well as other damages in the airways.
52 studies on the registry are indexed under Hoarseness; 9 are open to participants now.
This study's enrollment of 9 is below the median of 108 across 44 interventional studies indexed under Hoarseness.
Browse Hoarseness studies →Karolinska University Hospital is the lead sponsor of 279 studies on the registry; 55 are open to participants now.
Counted across the registry records on this site, refreshed daily.
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.
Exclusion Criteria:
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.
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.
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.
Hepatitis C is a virus that infects the liver. An HCV antibody test can stay positive after an infection has cleared (and is occasionally positive without one); an HCV RNA test shows whether the virus is there now.
After treatment, hepatitis C counts as cured when HCV RNA is still undetectable 12 weeks or more after the treatment ended. Studies often accept people cured this way.
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.
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.
Hepatitis C tests
Hepatitis C is a virus that infects the liver. An HCV antibody test can stay positive after an infection has cleared (and is occasionally positive without one); an HCV RNA test shows whether the virus is there now.
After treatment, hepatitis C counts as cured when HCV RNA is still undetectable 12 weeks or more after the treatment ended. Studies often accept people cured this way.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
1 single arm: Local injection of autologus MSC product (KI-MSC-PL-204) into scarred vocal fold (0,5-1 million cellls/Vocal fold, maximum 2 million cells if bilateral vocal fold scar)
Biological: MSC-KI-PL-204
Autologous MSC product
Safety and tolerability of treatment
Number of serious adverse events/ adverse events treatment and conseques
Time frame: 3 year
Assessment of VF function by high speed laryngeal/stroboscopy recordings
Description: Assessment of VF function change from baseline to 1 year after treatment, as evaluated by an expert panel of high speed laryngeal/stroboscopy recordings. (Expert panel catagories: (Improved, unchanged, deteriorated)
Time frame: from baseline to 1 year after treatment.
Assessment of subjective VHI change (points)
Assessment of patient´s subjective VHI (voice handicap index) ratings change (points)
Time frame: changes from baseline to 1 year after treatement
Assessment of Phonation Threshold Pressure changes (cmH2O)
Measurements of phonation threshold pressure (PTP) changes from baseline to 1 year after treatment
Time frame: changes from baseline to 1 year after treatment
Assessment of perceptual voice analysis changes (points)
Evaluation by an expert panel of perceptual voice parameters, changes from baseline to 1 year after treatment
Time frame: changes from baseline to 1 year after treatment
Assessment of subjective VFI change (points)
Assessment of Vocal fatigue index (VFI) changes from baseline to 1 year after treatment
Time frame: from baseline to 1 year after treatment
Assessment of maximum phonation time change (seconds)
Measurements of maximum phonation time change from baseline to 1 year after treatment
Time frame: from baseline to 1 year after treatment
Ran from Mar 2021 to primary completion in Jan 2025, 46 months.
How these figures are worked out, and which studies are left out of them.
This study is completed, as verified in Mar 2025. You cannot join it, but the record below documents what was studied.
Get an email when the registry record changes — status, dates, results — or when someone posts here.
Sign in to followQuestions and observations about this study, from anyone following it. Not medical advice, and not a channel to the study team — their contact details are on the registry record.
Sign in to join the discussion. Reading takes no account; posting does. You choose a display name, and a pseudonym is the default.
Nothing here yet. If you are running this trial, taking part in it, or weighing whether to, this is the place to say so.
Karolinska University Hospital →