Leroy Leo e Bhanvi Satija su Reuters danno notizia della approvazione di due differenti terapie geniche per il trattamento dell’anemia a cellule falciformi.

L’anemia a cellule falciformi, una malattia in cui una mutazione del gene dell’emoglobina causa la deformazione dei globuli rossi, che così tendono ad aggregarsi e a ostruire i capillari.

Una delle due terapie approvate si basa sull’editing genetico con la tecnologia CRISPR, già usata per altre condizioni. L’altra si basa sulla introduzione dei geni corretti per il tramite di un vettore virale. Tutte e due debbono essere praticate dopo la “ablazione midollare”, cioè il trattamento usato anche per i trapianti di midollo per le leucemie che non rispondono alle terapie convenzionali. Il sito della Food & Drugs Administration entra più nel dettaglio delle terapie:

CRISPR/Cas9 can be directed to cut DNA in targeted areas, enabling the ability to accurately edit (remove, add, or replace) DNA where it was cut. The modified blood stem cells are transplanted back into the patient where they engraft (attach and multiply) within the bone marrow and increase the production of fetal hemoglobin (HbF), a type of hemoglobin that facilitates oxygen delivery. In patients with sickle cell disease, increased levels of HbF prevent the sickling of red blood cells.

Lyfgenia is a cell-based gene therapy. Lyfgenia uses a lentiviral vector (gene delivery vehicle) for genetic modification and is approved for the treatment of patients 12 years of age and older with sickle cell disease and a history of vaso-occlusive events. With Lyfgenia, the patient’s blood stem cells are genetically modified to produce HbA^T87Q, a gene-therapy derived hemoglobin that functions similarly to hemoglobin A, which is the normal adult hemoglobin produced in persons not affected by sickle cell disease. Red blood cells containing HbA^T87Q have a lower risk of sickling and occluding blood flow. These modified stem cells are then delivered to the patient.

La notizia ha provocato subbuglio anche in borsa

The Vertex-CRISPR therapy has a U.S. list price of $2.2 million, while bluebird’s is $3.1 million. Both therapies, pitched as one-time treatments, will be available in early 2024.

Two Wall Street analysts said bluebird’s higher price and safety warning would hinder its sales in comparison to Casgevy.

Shares of bluebird fell 40% on Friday, while U.S.-listed shares of CRISPR Therapeutics fell 8% and those of Vertex dropped 0.5%.