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
Early Screening and Treatment of Heart Complication in Sickle Cell Disease
This study tests whether early heart screening and treatment for iron overload in subjects with sickle cell disease can prevent heart problems and reduce hospitalizations.
A Research Study Looking at Long-term Treatment With Etavopivat in People With Sickle Cell Disease or Thalassaemia
Etavopivat is a new medicine under development for treating blood disorders like sickle cell disease and thalassaemia. Sickle cell disease and thalassaemia are inherited blood disorders that affect haemoglobin. Haemoglobin is the protein that carries oxygen through the body. This study is looking into how safe treatment with etavopivat is and how well it works over a long period of time. The study will last for up to 264 weeks, but it will end earlier if etavopivat is approved in the participant's country.