A Phase 3 interventional study of FXS6837 Capsule in Paroxysmal Nocturnal Hemoglobinuria, sponsored by Shanghai Fosun Pharmaceutical Industrial Development Co. Ltd.. Not yet recruiting at 2 sites in China. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-11-04.
Sponsored by Shanghai Fosun Pharmaceutical Industrial Development Co. Ltd. (part of Fosun Pharma) · Phase 3, Interventional, and Treatment
This is an single arm, open label designed phase III study to evaluate the efficacy and safety of oral FXS6837 capsules in PNH patients with residual anemia despite the stable treatment with anti-C5 antibody.
About 20 PNH patients who have received eculizumab stably for at least 6 months before first dosing and still have hemoglobin (Hb) \< 100 g/L will be eligible to be enrolled. All patients will take FXS6837 capsules for 24 weeks according to protocol to evaluate the efficacy and safety of FXS6837 Capsules in PNH patients who remain anemic after anti-C5 monoclonal antibody therapy. After completing the 24-week treatment, all participants who are assessed by the investigator as potentially continuing to benefit from FXS6837 may voluntarily enter a separate long-term open-label extension stud and continue to receive FXS6837 treatment.
191 studies on the registry are indexed under Hemoglobinuria, Paroxysmal; 49 are open to participants now.
This study's planned enrollment of 20 is below the median of 33 across 150 interventional studies indexed under Hemoglobinuria, Paroxysmal.
Browse Hemoglobinuria, Paroxysmal studies →Shanghai Fosun Pharmaceutical Industrial Development Co. Ltd. is the lead sponsor of 34 studies on the registry; 21 are open to participants now.
Counted across the registry records on this site, refreshed daily.
Inclusion criteria: 1. Male or female subjects aged ≥ 18 years at screening; 2. Body weight ≥ 40 kg and (BMI) ≥ 18 kg/m2 at screening; 3. Diagnosis of PNH at least 6 months before screening and confirmed by high-sensitivity flow cytometry with a PNH RBC and granulocyte/monocyte population size of ≥10% within 6 months before screening or during screening; 4. Have received a stable treatment regimen (dose and dosing interval) with anti-C5 monoclonal antibody (eculizumab) for at least 6 months prior to the first dose; 5. Have at least one blood transfusion record within 3 months before screening, or level persistently \< 100 g/L during stable treatment with anti-C5 monoclonal antibody within 3 months before screening (medical history data/laboratory test reports, at least 2 test records with an interval of ≥ 4 weeks); 6. Hb meeting one of the following conditions: (1) Hb concentration \< 100 g/L at the first screening visit, and received RBC transfusion therapy due to PNH-related anemia during the screening period; (2) Mean Hb concentration from two measurements during the screening period \< 100 g/L and all Hb measurements \< 105 g/L during the screening period (these two measurements should be 2 to 6 weeks apart; multiple Hb measurements are allowed during the screening period); 7. Vaccinated against Neisseria meningitidis and Streptococcus pneumoniae before the first dose. If patients have not been previously vaccinated or need booster vaccination (according to local vaccination policies), vaccination should be completed at least 2 weeks before the first dose. If the first dose must occur within 2 weeks after vaccination, prophylactic antibiotic treatment should be used until at least 2 weeks after vaccination; 8. Participants of commit to having no plans for pregnancy or sperm/egg donation from screening until 1 month (female participants) or 3 months (male participants) after the last dose and voluntarily take effective physical methods (including partners); 9. Have a detailed understanding of the nature, significance, possible benefits, potential inconveniences, and potential risks of the trial, and voluntarily participate in this clinical trial; Able to communicate well with the investigators and comply with the requirements of the entire study; Signed a written form. Exclusion criteria: 1. With laboratory evidence of bone marrow failure during screening (reticulocyte count \< 100 × 109/L, or count \< 30 × 109/L, or \< 0.5 × 109/L); Received acute treatment (such as platelet transfusion, granulocyte colony-stimulating factor) for thrombocytopenia or neutropenia within 30 days before screening; 2. Participants receiving other therapies before screening that have not reached the following stable treatment durations:
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.
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.
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).
Able to have children. For women this usually means from the first period until menopause, unless permanently unable to through surgery; for men, unless permanently sterile. Read who the line is about — participants, women, men, or their partners.
Criteria about it usually ask for contraception during the study and for a time after it.
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
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.
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.
The number of neutrophils, white blood cells that help fight infection, in a given amount of blood. Too few raises the risk of infection.
It is a count, not a percentage of the white cells. Limits are written in units that mean the same: ≥ 1.5 × 10⁹/L is ≥ 1,500 per mm³ (µL). Each lab has its own reference range.
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.
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.
Blood tests of how long blood takes to clot. The INR is the prothrombin time (PT) put on a common scale; about 1 is usual for someone not taking a blood thinner.
Criteria often make an exception for people on a blood thinner such as warfarin, whose INR is raised on purpose.
Cancer that has spread from where it began to other parts of the body. “Metastatic” cancer is cancer that has spread this way.
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.
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.
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.
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.
Vaccines made with a weakened form of the germ, such as measles–mumps–rubella (MMR), chickenpox and yellow fever. They can be risky when the immune system is weakened. Flu injections are not live; the nasal flu spray is.
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
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.
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.
Reproductive potential
Able to have children. For women this usually means from the first period until menopause, unless permanently unable to through surgery; for men, unless permanently sterile. Read who the line is about — participants, women, men, or their partners.
Criteria about it usually ask for contraception during the study and for a time after it.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraception
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
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.
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.
Absolute neutrophil count (ANC)
The number of neutrophils, white blood cells that help fight infection, in a given amount of blood. Too few raises the risk of infection.
It is a count, not a percentage of the white cells. Limits are written in units that mean the same: ≥ 1.5 × 10⁹/L is ≥ 1,500 per mm³ (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.
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.
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.
INR, PT and aPTT (clotting tests)
Blood tests of how long blood takes to clot. The INR is the prothrombin time (PT) put on a common scale; about 1 is usual for someone not taking a blood thinner.
Criteria often make an exception for people on a blood thinner such as warfarin, whose INR is raised on purpose.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Metastases
Cancer that has spread from where it began to other parts of the body. “Metastatic” cancer is cancer that has spread this way.
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.
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.
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.
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.
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.
Live vaccines
Vaccines made with a weakened form of the germ, such as measles–mumps–rubella (MMR), chickenpox and yellow fever. They can be risky when the immune system is weakened. Flu injections are not live; the nasal flu spray is.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Investigational drug or device
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
100 mg FXS6837 capsule
Drug: FXS6837 Capsule
FXS6837 capsule will be taken orally for 24 weeks
Proportion of participants with hemoglobin (Hb) level ≥ 120 g/L in at least 3 of 4 measurements between Week18 and Week24 in the absence of RBC transfusion (defined as no RBC transfusion after Week2 through Week24)
Time frame: 24 weeks from Baseline (Week 18 through Week 24)
Proportion of participants with an increase from baseline in Hb level of ≥ 20 g/L in at least 3 of 4 measurements between Week18 and Week24 in the absence of RBC transfusion (defined as no RBC transfusion after Week2 through Week24)
Time frame: 24 weeks from Baseline (Baseline, Week 18 through Week 24)
Proportion of participants without RBC transfusion during the treatment period from between Week2 to Week24
Time frame: Week2 to Week24
Change from baseline in Hb as mean of visits between Week18 and Week24
Time frame: 24 weeks from Baseline (Baseline, Week 18 through Week 24)
Change from baseline in reticulocyte count during the treatment period from Week18 to Week24
Time frame: 24 weeks from Baseline (Baseline, Week 18 through Week 24)
Percent change from baseline in lactate dehydrogenase (LDH) levels during the treatment period from Week18 to Week24
Time frame: 24 weeks from Baseline(Baseline, Week 18 through Week 24)
Proportion of participants with LDH ≤ 1.5 × upper limit of normal (ULN) in at least 3 of 4 measurements between Week18 and Week24;
Time frame: 24 weeks from Baseline (Week 18 through Week 24)
Change from baseline in Functional Assessment of Chronic Illness Therapy - Fatigue Scale (FACIT-Fatigue) score during the treatment period from Week18 to Week24
Time frame: 24 weeks from Baseline (Baseline, Week 18 through Week 24)
Incidence rate of BTH between Week1 and Week24
Time frame: up to 24 weeks
Incidence of MAVEs between Week1 and Week24
Time frame: up to 24 weeks
Safety evaluation: All participants will be observed for any adverse event (AE) during the clinical study.
Time frame: up to 24 weeks
Population Pharmacokinetics (PK): Maximum Observed Concentration (Cmax) of FXS6837
Time frame: From pre-dose on Day1 to Week24
Population Pharmacokinetics (PK): Plasma trough concentration (Ctrough) of FXS6837
Time frame: From pre-dose on Day1 to Week24
Population Pharmacokinetics (PK): Area Under the Concentration-Time Curve (AUC) of FXS6837
Time frame: From pre-dose on Day1 to Week24
The exposure-response correlation between Steady-State trough Concentration (Ctrough) of FXS6837 and hemoglobin (Hb) level
Time frame: From pre-dose on Day1 to Week24
The exposure-response correlation between Steady-State trough Concentration (Ctrough) of FXS6837 and lactate dehydrogenase (LDH) level
Time frame: From pre-dose on Day1 to Week24
The exposure-response correlation between Steady-State trough Concentration (Ctrough) of FXS6837 and Alternative Pathway(AP) activity
Time frame: From pre-dose on Day1 to Week24
The exposure-response correlation between Steady-State trough Concentration (Ctrough) of FXS6837 and Fragment Bb of Complement Factor B level
Time frame: From pre-dose on Day1 to Week24
The exposure-response correlation between Steady-State trough Concentration (Ctrough) of FXS6837 and soluble C5b-9 (sC5b-9) level
Time frame: From pre-dose on Day1 to Week24
The exposure-response correlation between Steady-State trough Concentration (Ctrough) of FXS6837 and PNH granulocyte clone percentage
Time frame: From pre-dose on Day1 to Week24
The exposure-response correlation between Steady-State trough Concentration (Ctrough) of FXS6837 and PNH monocyte clone percentage
Time frame: From pre-dose on Day1 to Week24
The exposure-response correlation between Steady-State trough Concentration (Ctrough) of FXS6837 and C3d+PNH red cell clone percentage
Time frame: From pre-dose on Day1 to Week24
The exposure-response correlation between Steady-State trough Concentration (Ctrough) of FXS6837 and PNH red cell clone percentage
Time frame: From pre-dose on Day1 to Week24
Start is estimated for Jan 2027; primary completion for May 2028, 15 months later.
Of 35 industry-sponsored phase 3 interventional studies under Hemoglobinuria, Paroxysmal, half reached primary completion within 23 months of starting (the median), counting those still running; a quarter within 15 and three quarters within 41. This study's planned 15 months is below that.
Counting every sponsor, half of 35 studies reached it within 23 months; a quarter within 15 and three quarters within 41.
How these figures are worked out, and which studies are left out of them.
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 ↗
This study is not yet recruiting, as verified in Oct 2026. You cannot join it, but the record below documents what was studied.
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Studies of the drug tested here: FXS6837
Shanghai Fosun Pharmaceutical Industrial Development Co. Ltd. →