This is an archive article published on November 25, 2023

Opinion For sickle-cell anaemia, a new cure — for millions, a new hope

Express View: Research on cell editing therapy is, by all accounts, at a relatively nascent stage in India. This success should spur investments in this field

sickle cell, Arevolutionary gene-editing therapy, sickle-cell anaemia, sickle cell anaemia patients, use of Casgevy, gene-editing tools, CRISPR-Cas 9, chemotherapy, hydroxyurea, green light, indian express news

In sickle cell disease, the oxygen-carrying protein in red blood cells, haemoglobin, is compromised. Red blood cells with normal haemoglobin are disk-shaped and flexible.

By: Editorial

November 25, 2023 07:06 AM IST First published on: Nov 25, 2023 at 07:06 AM IST

Arevolutionary gene-editing therapy holds out hope for millions of sickle cell anaemia patients across the world, including in India, where about 30,000 to 40,000 children are born with the disorder every year. Last week, the UK became the first country to approve the use of Casgevy, which uses the gene-editing tool CRISPR-Cas 9.

The current remedy for the disease involves chemotherapy, hydroxyurea, which reduces the frequency of complications in patients. The UK regulator’s decision was based on Casgevy’s impressive ability to eliminate painful inflammatory attacks in more than 90 per cent of trial participants. The green light could pave the way for approvals by the US FDA — it’s slated to take a decision on December 8 — and other regulatory bodies.

However, much needs to be done before the therapy becomes accessible to all. Making room for edited cells in the body is a complicated procedure. Vertex, the company that manufactures Casgevy, hasn’t quoted a price for the therapy, but estimates from the UK and the US have pegged treatment costs for an individual patient at about $2 million.

In sickle cell disease, the oxygen-carrying protein in red blood cells, haemoglobin, is compromised. Red blood cells with normal haemoglobin are disk-shaped and flexible. They move through the blood vessels easily. The haemoglobin-deficient cells are an almost exact contrast. When they lose their oxygen, these cells assume a crescent shape. They die much more rapidly than their normal counterparts. Their shape makes the sickle cells stick to blood vessels, blocking the movement of oxygen-carrying blood and leading to life-threatening conditions.

With less healthy red blood cells circulating in their body, patients become chronically anaemic. The disorder is genetic. Casgevy does not remove the mutation that is at the root of the disease. But it’s designed to compensate for the haemoglobin by reviving the fetal haemoglobin, which gets switched off shortly after birth.

India has the second highest burden of sickle cell disease, which predominantly affects the country’s tribal population. The Union Budget 2023 introduced the National Sickle Cell Anaemia Elimination Programme to address the challenges posed by the disorder. The programme — envisaged when preliminary results on the gene therapy were trickling in — aims to eliminate the disease by 2047. At current costs, Casgevy seems prohibitive for the country. However, research institutions should explore the possibilities offered by gene editing to develop affordable therapies.

Gene research institutions played a significant role in the management of Covid. But research on cell editing therapy is, by all accounts, at a relatively nascent stage in India. Casgevy’s success should spur investments in this field.

# sickle cell disease