Vertex unveiled long-term durability data for Casgevy, while Beam presented Phase I/II findings for its investigational base editor BEAM-101, building up to a BLA by late 2026.
At the ongoing 66th annual meeting of the American Society of Hematology in San Diego, Vertex Therapeutics and Beam Therapeutics are presenting novel data on the safety and efficacy of gene therapies for sickle cell disease.
In a presentation set for Monday evening, Vertex will unveil long-term data for its CRISPR Therapeutics-partnered Casgevy (exagamglogene autotemcel) demonstrating that the gene therapy eliminated vaso-occlusive crises (VOC) in 90% of patients after at least 16 months of follow-up. Over the same time duration, 95% were free of hospitalizations related to severe VOCs for at least 12 consecutive months.
Freedom from VOCs was maintained for up to 4.7 years, according to Vertex’s abstract.
Importantly, all patients—even those who did not achieve VOC elimination—showed higher levels of hemoglobin and fetal hemoglobin after Casgevy treatment. The gene therapy also led to “stable allelic editing,” which suggests that its effects are “durable over time in all patients,” according to the researchers.
Patients treated with Casgevy also saw “clinically meaningful improvements” in quality of life from baseline. As for safety, Vertex and CRISPR’s gene therapy was well-tolerable overall and was not linked with any serious toxicities in the study. There were also no dropouts or malignancies reported. One patient in the study died of COVID-19-related respiratory failure.
In a weekend note to investors, BMO Capital Markets analysts wrote that with these data, they “expect Casgevy to remain the leading busulfan-based ex vivo treatment for SCD.” Despite a competitive efficacy and safety profile from bluebird’s Lyfgenia, the BMO analysts don’t see the biotech as posing any substantial threat to Vertex and CRISPR due to its financial headwinds and U.S.-only focus, they noted.
The recently announced SCD gene therapy payment model of the Centers for Medicaid and Medicare Services is likely to “further accelerate Casgevy uptake in 2025,” the analysts added.
Also at ASH 2024, Beam on Sunday presented initial Phase I/II findings for its cell therapy BEAM-101, data that the BMO analysts said pointed to “a potentially best-in-class profile.”
According to the biotech’s abstract, BEAM-101 was rapidly engrafted into patients, which led to improvements in markers of hemolysis such as lactate dehydrogenase and indirect bilirubin. Fetal hemoglobin induction was “rapid and robust” and all four dosed patients saw marked improvements in anemia.
Of note, there were no cases of severe VOCs in the Phase I/II study after treatment. One patient in the study died four months after infusion, but the Beam researchers said that this was “likely related to busulfan conditioning.” Otherwise, there were no other adverse events grade 3 and above related to BEAM-101.
“We think BEAM-101 clinical data further derisk base editing,” BMO analysts said in a separate weekend note, adding that the cell therapy’s lower number of cell mobilization cycles “can be a differentiating edge in the clinic” versus Casgevy. Beam is targeting 30 dosed patients by mid-2025, opening a path for a Biologics License Application by late 2026.
