18 and older, any sex, with Chronic Phase Myelofibrosis or Primary Myelofibrosis. Patients with the condition only — healthy volunteers not accepted.
Results — posted to ClinicalTrials.gov
Per-arm endpoint measurements with 95% confidence intervals where reported. Source: trial results section.
European Leukemia Net -International Working Group (ELN-IWG) CriteriaPrimary· 18 weeks
The proportion of treated MF-CP patients (primary cohort) that achieve at least a clinical improvement (CI, PR, CR) by combined European Leukemia Net -International Working Group (ELN-IWG) criteria after 6 cycles of pembrolizumab therapy.
Complete Remission - CR: Bone marrow: Age-adjusted normocellularity; \<5% blasts; ≤grade 1 MF and Peripheral blood: Hemoglobin ≥100 g/L and \<UNL; neutrophil count ≥ 1 × 109/L and \<UNL; Platelet count ≥100 × 109/L and \<UNL; \<2% immature myeloid cells and Clinical: Resolution of disease symptoms; spleen and liver not palpable; no evidence of EMH Partial Re
The proportion of treated MPN-AP/BP patients (exploratory cohort) that achieve at least a complete morphologic remission of the leukemic blasts (CR, Cri) by Acute Myeloid Leukemia Response Criteria within 6 cycles of pembrolizumab therapy.
Acute Myeloid Leukemia Response Assessment Criteria:
Complete Response (CR) - The subject must be free of all symptoms related to leukemia and have an absolute neutrophil count of greater than 1 x 109/L, no need for red blood cell transfusion, platelet count greater than 100x 109/L, and normal marrow differential (\<5% blasts) in a normo- or hypercellular
Group
Value
95% CI
Pembolizumab
0
Adverse events — posted to ClinicalTrials.gov
Time frame: 18 weeks.
Reporting threshold: 0%.
Adverse-event reports describe events observed during the trial — not all are caused by the drug.
The purpose of this study is to test the effectiveness of a drug called pembrolizumab in patients with Myeloproliferative Neoplasm (MPN); chronic phase (MF-CP), accelerated phase (MPN-AP), or blast phase (MF-BP). Myelofibrosis neoplasm (MPN) is a group of diseases of the bone marrow in which excessive cells are produced.
Pembrolizumab also known as Keytruda is a drug that has recently been approved in the United Stated by the Food and Drug Administration (FDA) for the treatment of patients with unresectable or metastatic melanoma and disease progression. Pembrolizumab is experimental in the treatment of MPN. The researchers want to find out what effects, good and /or bad it has on participants and the disease.
Participants qualify to take part in this research study if have been diagnosed with a MPN blood disorder called myelofibrosis (MF). Accelerated (10-19% blasts in the blood or bone marrow) and blast phase (\>20% blasts in the blood or bone marrow) MPN has been a difficult disease to treat. The term "blasts" refers to immature cells found in the bone marrow. They are not fully developed, and therefore, do not yet carry out any particular function within the body.
Funds for conducting this research are provided by Merck and Company, the manufacturer of the study drug pembrolizumab.
Publications & conference data
8 peer-reviewed publications reference this trial (live from Europe PMC):
NCT07572123 — Evaluating the Addition of Maintenance Immunotherapy Compared to the Usual Treatment of Chemotherapy and Autologous Stem
· Phase 2, PHASE3
· not yet recruiting
NCT07275216 — Pembrolizumab in Combination With Chemotherapy for the Treatment of Frail Hodgkin Lymphoma Patients Ineligible for Stand
· Phase 2
· not yet recruiting
NCT07302347 — A Study of Pembrolizumab in Japanese Pediatric Participants With Solid Tumors or Lymphomas and Japanese Adult Participan
· Phase 1, PHASE2
· recruiting
NCT06724042 — Study of ISM5939 in Patients With Advanced and/or Metastatic Solid Tumors
· Phase 1
· not yet recruiting
NCT07383441 — Adding Biotherapy or Placebo to Standard Treatment for Advanced Kidney Cancer
· Phase 3
· not yet recruiting
Other John Mascarenhas trials
Trials by the same sponsor.
NCT07447817 — Selinexor and Pacritinib in JAK Inhibitor-naïve MF Patients With Cytopenias
· Phase 2
· not yet recruiting
NCT05467800 — Study of Canakinumab in Patients With Myelofibrosis
· Phase 2
· recruiting
NCT04281498 — Combined Ruxolitinib and Enasidenib in Patients With Accelerated/Blast-phase Myeloproliferative Neoplasm or Chronic-phas
· Phase 2
· completed
Publications: Europe PMC API search by NCT ID, retrieved 10 June 2026
Drug + disease cross-links: matched in real time against Drug Landscape's normalised drug + company + condition tables
Sponsor: as reported to ClinicalTrials.gov by John Mascarenhas
Last refreshed: 21 June 2021
Drug Landscape aggregates and links these public records for informational use only. Always verify against the primary source before clinical or regulatory decisions. Canonical URL: https://druglandscape.com/trial/NCT03065400.