BioPharma Dive: Progress and competition in gene therapy for sickle cell disease

This is different from the gene editing methods used by several other major developers
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At least two sets of partners-CRISPR and Vertex, as well as Novartis and Intellia Therapeutics-are using the Nobel Prize-winning CRISPR-cas9 technology to allow hematopoietic stem cells to produce high levels of fetal hemoglobin (HbF)
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Fetal hemoglobin is an important protein, but it stops producing about 6 months after birth
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In theory, the use of gene editing technology to keep the switch producing this protein on can help solve the main problems associated with SCD
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Gene therapy has shown promise for treating SCD
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A small study conducted on LentiGlobin found that after treatment, patients' hemoglobin levels were close to normal, and almost no patients experienced vascular occlusive crisis or acute chest syndrome, which is another symptom of SCD
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CRISPR and Vertex also made similar positive updates to their projects last month
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The two companies said that a small group of SCD patients treated with their therapy CTX001 did not experience a vascular occlusive crisis after treatment
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The data also shows that CTX001 can produce lasting effects
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However, these breakthroughs were accompanied by setbacks
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The Bluebird LentiGlobin project has been delayed many times due to production and safety issues
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In February of this year, the company stopped two sickle cell studies because one patient developed acute myeloid leukemia (AML) and the other patient appeared to have myelodysplastic syndrome (MDS)
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Since then, Bluebird has conducted an investigation and determined that LentiGlobin is "very unlikely" to be related to these cancer cases
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In April of this year, Bluebird Bio updated its diagnosis of a suspected MDS case, saying that after additional testing, this patient was not a MDS case, but a transfusion-dependent anemia
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The company has notified regulators and researchers of this latest situation
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What's the next step?

In June, Bluebird was approved to resume SCD research
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Before the study was suspended, the company had stated that it planned to submit a listing application by the end of 2022, but it may now be postponed
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An analysis by investment bank Raymond James shows that sticking to this timetable will put Bluebird Bio far ahead of other competing therapies
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Followed by the CRISPR and Vertex projects, analysts believe that the project may be submitted for approval within two or three years
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However, after the test started slowly, it is now advancing rapidly
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In addition, gene therapies from Aruvant Sciences and Sanofi/Sangamo Therapeutics are expected to submit applications within three to five years
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At the same time, there are still many uncertain factors that need to be addressed
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Researchers are still trying to understand whether genetic medicine can work for all SCD patients, or whether it can realize its lifelong potential for treating SCD
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Even if these gene therapies enter the market, they may face challenges
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For example, gene therapies currently under development require the use of toxic pretreatment protocols to treat patients, which may limit who can or is willing to receive such treatments
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Reference source: Gene therapy for sickle cell disease: progress and competition