A Phase 2 interventional study of Senicapoc and Placebo in Sickle Cell Disease, Sickle Cell Anaemia and Sickle Cell Anemia, sponsored by Biossil Inc.. Recruiting at 4 sites in Canada. Open to participants aged 16 Years to 50 Years. Per ClinicalTrials.gov, last updated 2026-11-02.
Sponsored by Biossil Inc. · Phase 2, Interventional, and Treatment
SIL-8301 (senicapoc) is being developed for the chronic treatment of patients with sickle cell disease in both adults and children. The purpose of this study is to compare the effects of senicapoc to placebo in patients with sickle cell disease that have had fewer than 2 acute sickle-related painful crises per year over the preceding 2 years, and have a predominantly hemolytic phenotype, defined as evidence of ongoing hemolysis and a baseline Hb of 9.5 g/dL or less, despite receiving hydroxyurea (an oral drug used for treatment of sickle cell disease) as standard of care. Participants will take senicapoc or matching placebo daily and continue on hydroxyurea as prescribed for up to 24 weeks. Eligible participants that complete the 24 weeks will have an opportunity to receive senicapoc for up to 2 years in an optional open label extension.
1,134 studies on the registry are indexed under Anemia, Sickle Cell; 238 are open to participants now.
This study's planned enrollment of 65 is above the median of 40 across 769 interventional studies indexed under Anemia, Sickle Cell.
Browse Anemia, Sickle Cell studies →Biossil Inc. is the lead sponsor of 2 studies on the registry; 1 is open to participants now.
Counted across the registry records on this site, refreshed daily.
The criteria were revised on the registry on Nov 2, 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.
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.
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 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.
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.
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.
20 mg twice daily for 4 days, followed by 10 mg once daily for up to 24 weeks
Drug: Senicapoc
Matching placebo tablets twice daily for 4 days, followed by once daily for up to 24 weeks
Drug: Placebo
10 mg tablets; administered at a loading dose of 20 mg twice daily for 4 days, followed by a maintenance dose of 10 mg once daily for up to 24 weeks
Also known as: SIL-8301
Tablets similar in size and color; matching administration schedule
Hb response rate
Proportion of participants achieving an increase in Hb of \> 1 g/dL from baseline
Time frame: 24 Weeks
Change from baseline in Hb (g/dL)
Time frame: 24 Weeks
Change from baseline in lactate dehydrogenase (LDH) (u/L)
Time frame: 24 Weeks
Change from baseline in indirect bilirubin (µmol/L)
Time frame: 24 Weeks
Change from baseline in reticulocyte count (%)
Time frame: 24 Weeks
Proportion of participants with a Hb increase of > 2g/dL from baseline
Time frame: 24 Weeks
Percent change from baseline in urine albumin-creatinine ratio (uACR)
Time frame: 24 Weeks
Change from baseline in overall score and subscale domain scores of the Participant-Reported Outcomes Measurement Information System (PROMIS)
The PROMIS-29 assessment for adult participants assesses depressive symptoms, anxiety, physical function, pain interference, fatigue, sleep disturbance, and ability to participate in social roles and activities. The PROMIS Pediatric-25 assessment for participants \<18 years of age assesses depressive symptoms, anxiety, physical function and mobility, pain interference, fatigue, and peer relationships. For both PROMIS assessments, a higher score indicates worse symptoms except for higher physical function values which indicate better physical function.
Time frame: 24 Weeks
Sickle cell disease complication rate
Proportion of participants experiencing at least one new or worsening hemolytic complication at any time during the study
Time frame: 24 Weeks
Proportion of participants with at least one category of improvement from baseline in Clinician and Patient Global Impression of Change
Time frame: 24 Weeks
Frequency of acute sickle cell-related painful crises
Time frame: 28 Weeks
Incidence of AEs, SAEs, and sickle cell disease related AEs
Time frame: 28 Weeks
Start is estimated for Nov 2026; primary completion for Oct 2029, 35 months later.
Of 34 industry-sponsored phase 2 interventional studies under Anemia, Sickle Cell, half reached primary completion within 28 months of starting (the median), counting those still running; a quarter within 16 and three quarters within 41. This study's planned 35 months is above that.
Counting every sponsor, half of 92 studies reached it within 46 months; a quarter within 24 and three quarters within 73.
Since we started tracking on Sep 25, 2026, the dates moved once, on Nov 2, 2026: start Aug 2026 → Nov 2026, primary completion Jan 2029 → Oct 2029 and completion Feb 2029 → Oct 2031.
Earlier changes are on the record history on ClinicalTrials.gov ↗
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 ↗
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Studies of the drug tested here: Senicapoc
Biossil Inc.