A new study, published in The New England Journal of Medicine in May this year, brought to light a unique case involving a 7-month-old baby, known as ‘KJ’, who was born with a life-threatening liver disorder known as carbamoyl phosphate synthetase 1 (CPS1) deficiency.
In the case, reported in February this year, it was for the first time that a gene-editing CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats)-based technology was used with a specific mutation in a living person. While the baby wasn’t fully cured, the treatment – a historic step towards personalised medicine – was initiated to ensure that any risks associated with the condition are minimised.
Explaining what personalised medicine is, Dr Shrinidhi Nathany, consultant, molecular haematology and oncology, Fortis Memorial Research Institute, Gurugram, explains, “Personalised medicine refers to a transformative approach in healthcare that uses an individual’s genetic, molecular, and clinical profile to guide diagnosis and treatment.”
Dr Mandeep Singh Malhotra, director of surgical oncology at the CK Birla Hospital, Delhi, explains, “Instead of using a one-size-fits-all method, personalised medicine involves evaluating the patient’s DNA and RNA to detect any aberrations in the genome that may be causing the disease. This helps in identifying the root cause of an illness, whether it’s a rare genetic disorder, cancer, or another condition, at a molecular level.”
The specific treatment method used in this case was gene-editing. Dr Sajjan Rajpurohit, senior director of medical oncology at BLK-Max Super Speciality Hospital, says, “Gene editing refers to a set of technologies that allow scientists to modify an organism’s DNA. One of the most well-known gene-editing techniques is CRISPR-Cas9, which enables precise alterations to specific genes. This technology has opened new avenues for treating genetic disorders by correcting mutations at their source.”
Up until now, gene editing and CRISPR-based therapy has been used to treat severe diseases like cancer, thalassemia, and sickle cell. The results of a clinical trial published by Vertex Pharmaceuticals and CRISPR Therapeutics in 2021 showed that 15 people with beta thalassemia who were treated with this method showed “rapidly improved haemoglobin levels and no longer required blood transfusions”. Seven of the sickle cell disease patients showed “increased levels of haemoglobin and reported at least three months without severe pain”.
How it works
But how is this treatment navigated through? Is it an intense form of therapy? Speaking from her experience at the Fortis Institute of Genomic Medicine, Dr Nathany explains, “We integrate advanced genetic testing into routine clinical care, helping identify actionable mutations and inherited risk factors across a wide range of conditions. This approach is especially powerful in cancer, where tumour profiling often reveals specific mutations or fusions that can be targeted with precision therapies.”
“One such case involved a patient with advanced non-small cell lung cancer (NSCLC), whose tumour showed a rare RET (rearranged during transfection) fusion on next-generation sequencing. This finding changed the treatment trajectory. Instead of standard chemotherapy, the patient was started on Pralsetinib, a targeted RET inhibitor. The result was a dramatic clinical response, with significant tumour shrinkage and symptom relief – demonstrating the power of matching the right drug to the right mutation,” adds Dr Nathany.
Dr Malhotra breaks this down in simple terms for us. Gene editing is basically an attempt to correct any abnormalities in our genetic code that might have been the causal factor of any disease or severe condition. He says, “For instance, if a mutation in a specific gene is responsible for a disease, modern gene-editing technologies can alter or replace that faulty sequence to restore normal function.”
This, he explains, has given way to targeted therapies for cancer treatment where specific pathways that are responsible for the tumour or uncontrolled cell growth are corrected in what is known as “precision oncology”. Dr Malhotra adds, “While gene editing is still emerging in cancer treatment, it has already shown promising results in treating certain genetic and viral conditions.”
To this, Dr Nathany adds, “Gene-focused medicine can help in rare diseases and inherited conditions. Tools like whole exome sequencing or gene panels can uncover causes of unexplained disorders – even in infants – and point toward targeted therapies or future gene-editing solutions.”
Dr Rajpurohit also mentions that personalised medicine is equally applicable in analysing and tailoring treatment for rare genetic disorders and infectious diseases like HIV.
Ifs and buts
While the applications of gene editing and personalised medicine are many, there are quite a few limitations still.For one, advanced genetic testing and targeted therapies are expensive. Not all of them are covered by insurance. Then, the infrastructure and expertise for these are also concentrated in metropolitan cities, making accessibility a big issue. Similarly, skilled professionals in this field are also few and far between.
Dr Malhotra makes an important point about how the process also involves “complex genomic sequencing and advanced lab analysis, much of which still requires samples to be sent to specialised labs abroad”.
“There’s also the challenge of data interpretation – having the genetic information is only the first step; making it clinically meaningful requires deep integration of bioinformatics, molecular pathology, and clinical insight,” says Dr Nathany. She adds, “Moreover, not all conditions are monogenic or targetable. Some diseases involve complex interactions of multiple genes and environmental factors, limiting the effectiveness of a single-drug, single-mutation approach. Ethical considerations around gene editing, especially in germline cells, also continue to evolve.”
Dr Malhotra of CK Birla, notes that “not all genetic aberrations are fully understood, which means some diseases still cannot be mapped accurately at the genomic level”.
Essentially, gene editing is still largely experimental, say experts, which brings in a lot of ethical concerns, regulatory hurdles, and the risk of unintended side effects. Dr Rajpurohit says, “Ongoing research is needed to fully understand the long-term effects and efficacy of personalised medicine. This research requires time and investment, which can slow down the availability of new treatments.”
“The future of personalised medicine will require collaboration between various fields, including genetics, oncology, pharmacology, and bioethics. This interdisciplinary approach will help ensure that advancements are made responsibly and effectively,” adds Dr Rajpurohit.
The next steps
All said and done, progress is still being made. Dr Malhotra says, “Several Indian labs and research institutions are now focusing on offering genomic testing and analysis at a more affordable scale. As these technologies become more indigenised, the cost is expected to reduce significantly, making personalised treatments more accessible.”
Dr Nathany agrees, saying that personalised medicine (which includes methods like gene editing) is the way to go because “the future of medicine isn’t one-size-fits-all-it’s one-in-a-billion”. She adds, “We’re moving rapidly toward an era of predictive, preventive, and truly personalised care.”
“In the coming years, we can expect a significant shift in how diseases are understood and treated, moving from symptomatic management to deeply personalised, genome-based interventions,” adds Dr Malhotra.