What the trial was testing
The RUBY Trial enrolled 45 patients with sickle cell disease. The study was sponsored by Editas Medicine and tracked outcomes across the full group of patients who matched the trial's eligibility profile.
It was an early-stage trial — researchers are still confirming safety and getting an early look at how well the treatment works. Trials at this stage are designed to produce evidence regulators and physicians can act on — not just observations to follow up later.
What the results showed
27 of 28 patients had no painful crises after treatment.
New England Journal of Medicine · 2026 · NCT04853576
These findings — that had no painful sickle cell crises after a one-time gene editing treatment — were published in the New England Journal of Medicine and represent the headline result of the study.
Researchers tracked outcomes across 45 patients enrolled in the trial. The result was consistent enough across the group that the team felt confident reporting it.
What this means for patients
For patients with sickle cell disease, this result changes the calculus on what to ask their care team about. Whether it changes day-to-day care depends on factors like disease subtype, prior treatments, and where the patient is in their care journey.
What you can do now
Reni-cel is not yet FDA-approved — this was a safety and early efficacy trial. Two other gene therapies (Casgevy and Lyfgenia) are already approved and may be available through your treatment center. Ask your hematologist about eligibility for approved gene therapies, and ask about any open gene editing trials.
Eligibility for the treatments mentioned above depends on specific test results and clinical history. Bring this summary, the trial name, and your most recent labs or pathology report to your next visit.
Open sickle cell disease trials
Myeloablative Conditioning, Prophylactic Defibrotide and Haplo AlloSCT for Patients With Sickle Cell Disease
This is a follow-up trial to NYMC 526 (NCT01461837) to assess the safety, efficacy and toxicity of administering Defibrotide prophylaxis for high-risk sickle cell or beta thalassemia patients undergoing a familial haploidentical or MUD allogeneic stem cell transplantation with CD34 enrichment and T-cell addback. This patient population historically has a risk of developing sinusoidal obstructive syndrome (SOS) and Defibrotide has demonstrated efficacy in treatment of SOS. The Funding Source is FDA OOPD.
A Trial to Assess Haploidentical T-depleted Stem Cell Transplantation in Patients With SCD
HSCT is currently the only curative option for SCD but less than 20% of SCD patients have a MD donor available. So far, all curative approaches beyond a MSD HSCT at young age are non-satisfactory. With the lack of a suitable donor for the vast majority of patients, the major question of this trial is, if a haploidentical αß/CD19+ T-cell depleted HSCT can be a valid alternative to a MSD HSCT. The main challenge in non-malignant diseases is to offer a safe and GvHD-free HSCT without rejection.