An observational study in Pyruvate Kinase Deficiency, Pyruvate Kinase Deficiency Anemia and Hereditary Hemolytic Anemia, sponsored by Massachusetts General Hospital. Completed at 1 site in United States. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-05-19.
Sponsored by Massachusetts General Hospital · Observational
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Among 14 studies in Myelodysplastic Syndromes by Massachusetts General Hospital — 1 open to participants now, 4 under way, none of them phase 3. Myelodysplastic Syndromes · Massachusetts General Hospital.
Among the 14 studies in Myelodysplastic Syndromes by Massachusetts General Hospital, this one is one of 2 that started in 2022, is the only observational one, and was the 12th registered.
1,997 studies on the registry are indexed under Myelodysplastic Syndromes; 324 are open to participants now.
Browse Myelodysplastic Syndromes studies →1 of the 14 studies in Myelodysplastic Syndromes by Massachusetts General Hospital is open now, in 1 country. Recruiting first, the newest first:
Massachusetts General Hospital · Sites in United States
Ages 18+
By country, each count listing its studies:
Of the 264 Myelodysplastic Syndromes studies recruiting now, 167 (63%) set no upper age limit and 70 (27%) stop at 75 or younger; 57 take children under 18; 17 take healthy volunteers.
This study: 18 Years and older · all sexes · no healthy volunteers.
The full table on the hub →This tab as a report to print or save as PDF → With an account.
14 studies; the count open now beside each. This study's row is marked.
First in 2002; this study’s year is marked. 2 started in 2022.
By drug class, each counting the studies that test any of its medicines:
This study's enrollment of 18 is below the median of 150 across 214 observational studies indexed under Myelodysplastic Syndromes.
Median enrollment 22 across the 13 interventional studies, 18 across the 1 observational. Of the 10 that completed or were terminated, 3 (30%) have results posted.
This tab as a report to print or save as PDF → With an account.
Massachusetts General Hospital is the lead sponsor of 2,589 studies on the registry; 447 are open to participants now.
Of its 223 completed or terminated interventional studies of FDA-regulated products, 168 (75%) have results posted.
None of the studies under way reaches primary completion within a year.
Among the 14 studies in Myelodysplastic Syndromes by Massachusetts General Hospital, from their registry updates:
Nothing recorded among them since 2026-09-25.
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This cross-sectional prevalence assessment study involves a single blood draw in specific patient populations to assess for enzymatic and genomic evidence for acquired pyruvate kinase deficiency.
This cross-sectional prevalence assessment study involves a single blood draw in specific patient populations to assess for enzymatic and genomic evidence for acquired pyruvate kinase deficiency.
The study will recruit patients to two separate cohorts.
It is expected that about 100 people will take part in this research study
Cohort 1 will recruit approximately 50 anemic (Hgb \<11.0 g/dL) MDS patients without overt clinical evidence of hemolysis. Cohort 2 will recruit approximately 50 patients with clonal myeloid disorders of any type with evidence of non-immune, otherwise unexplained hemolytic anemia.
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.
Cohort 1
Cohort 2
Exclusion Criteria:
Cohort 1
Cohort 2
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.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
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).
A yellow substance made when red blood cells are broken down, which the liver clears. A high level can mean a problem with the liver or the bile ducts.
Criteria often allow more for people with Gilbert’s syndrome, a harmless inherited condition that raises bilirubin.
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.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
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.
Bilirubin
A yellow substance made when red blood cells are broken down, which the liver clears. A high level can mean a problem with the liver or the bile ducts.
Criteria often allow more for people with Gilbert’s syndrome, a harmless inherited condition that raises bilirubin.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
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.
Approximately 75 anemic (Hgb \<11.0 g/dL) MDS Participants without overt clinical evidence of hemolysis. \- Single Blood Draw
Procedure: Blood Draw
25 Participants with clonal myeloid disorders of any type with evidence of non-immune, otherwise unexplained hemolytic anemia -Single Blood Draw
Procedure: Blood Draw
Blood specimen 2-4 teaspoons
Overall prevalence of possible or likely acquired pyruvate kinase deficiency
defined by PK enzyme activity or PK:HK ratio \>1 SD below the control mean (healthy subject mean) as measured by enzyme assay, or potentially pathogenic mutations in the PKLR gene as found on PKLR sequencing
Time frame: Day 1
Overall prevalence of definite acquired pyruvate kinase deficiency
Defined by PK enzyme activity below normal (or a PK:HK ratio \<8.7) as measured by enzyme assay, or known pathogenic mutations in the PKLR gene as found on PKLR sequencing
Time frame: Day 1
Red cell pyruvate kinase enzyme activity
Red cell pyruvate kinase enzyme activity in patients not receiving red cell transfusion in the 60 days prior to blood draw
Time frame: 60 days
Red cell pyruvate kinase
hexokinase enzyme activity ratio in patients not receiving red cell transfusion in the 60 days prior to blood draw
Time frame: 60 Day
Somatic mutations in PKLR (and other genes associated with acquired PKD) detected in the hematopoietic clone
Time frame: Day 1
Somatic mutations in other genes associated with hemolytic anemia detected in the hematopoietic clone
Time frame: Day 1
Characterization of pyruvate kinase-related red cell metabolites (ATP, 2,3-DPG) and pyruvate kinase-R protein in patients with clonal myeloid disorders
Time frame: Day 1
Impact of pyruvate kinase activators on PK activity in vitro
Time frame: Day 1
Characterization of other possible factors involved in acquired PKD, including acquired epigenetic or gene expression factors
Time frame: Day 1
Plan to share: Yes — The Dana-Farber / Harvard Cancer Center encourages and supports the responsible and ethical sharing of data from clinical trials. De-identified participant data from the final research dataset used in the published manuscript may only be shared under the terms of a Data Use Agreement. Requests may be directed to Sponsor Investigator or designee. The protocol and statistical analysis plan will be made available on Clinicaltrials.gov only as required by federal regulation or as a condition of awards and agreements supporting the research.
Supporting information: Study protocol, Statistical analysis plan
Time frame: Data can be shared no earlier than 1 year following the date of publication
Access criteria: Contact the Partners Innovations team at http://www.partners.org/innovation
No publications or documents are linked to this record.
Ran from Feb 2022 to primary completion in Feb 2026, 48 months.
Of 78 non-industry observational studies under Myelodysplastic Syndromes, half reached primary completion within 96 months of starting (the median), counting those still running; a quarter within 51. This study's 48 months is below that.
Counting every sponsor, half of 101 studies reached it within 84 months; a quarter within 34.
How these figures are worked out, and which studies are left out of them.
This study is completed, as verified in May 2026. You cannot join it, but the record below documents what was studied.
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