Gene therapy is one of the hottest topics of biotechnology’s vertical in this century. Once considered incurable genetic disorders, now have a cure that is cent per cent effective.
Among Scientists and researchers, Gene editing is the most intriguing method to cure any disease.
The aim of Gene therapy is to correct the genetic makeup of the patient by either adding, deleting or hiding the gene-altering the expression of the mutated gene. Today, if the person is suffering from a rare form of the genetic disorder, Gene therapy is the only option which offers then the maximum possibility of permanent cure by directly working on the root of the disease.
Over the years, Gene therapy has garnered much hype due to its ability to cure more than 10,000 genetic human ailments, with trials running in both animals and humans for finding a cure to more such disorders.
The idea of gene therapy is not a recent one. The idea originated in the late 1960s when scientists and researchers first tried to use the virus to incorporate the correct DNA/RNA to correct the mutated genetic material of the patient. However, at that time taking into consideration the dearth of the medically advanced technologies, the success rate of extracting and delivering the right copies of the genetic material was quite low.
Extensive research and advancements for a further three decades resulted in the first approved gene therapy in a four-year-old girl patient named Ashanthi DeSilva. She had a rare type of disease known as severe combined immunodeficiency, in which there is a deficiency of a gene namely ADA (adenosine deaminase). With the help of Gene editing tools, the scientists were able to insert the ADA gene to prevent her immune system from becoming vulnerable to infections.
This was the first milestone in the journey of the Gene therapy which would soon be a novel way of providing patients personalized and curative care.
From the moment the cause of the disorders being genomic mutations has been revealed, the emphasis to use the changes in the human genetic makeup and identify and cure the ailment has been there.
Gene therapy, which is considered a path-breaking discovery in the medical sector, is the ability which enables researches to mark the defect in the human genome and correct it by performing some alterations in the human genome.
To understand the complete genome sequence of a human, a project The Human Genome Project was undertaken, in the year 1990, that helped the Scientists to organize a blueprint of any person’s genetic makeup. The project, supported by the NNIH and the US FDA, was a joint effort to advance the healthcare domain across several geographies such as the United Kingdom, France, Germany, Japan, and China.
With time, and with better knowledge of the functioning of the genes, researchers are now able to use it for the benefit of human beings while treating a rare form of genetic disorders.
The completion of the project revealed the whole of the sequenced, high-quality human genome, which helped in bridging the voids. The genome helped in marking the locations of some of the significant loci and the structures of the genes.
The data obtained, for the betterment of the human race, was made available free with the help of the internet.
However, the path was not a cakewalk. Gene therapy, in order to achieve the status, it has today, had to cross several hurdles during its journey. The advanced bioengineering equipment that made it possible to point out mutation and manipulate the genome was one of the most vital processes of achieving the right output through Gene therapy. Manipulating the genome was one challenge, and delivering the same genome in the patient was another challenge that posed in front of the researchers.
The delivery of the right DNA sequence into the genome of the defected cells is the final task that decides the success rate of the gene therapy. For the delivery of the viral genus, special vehicles are used that are known as vectors. The vectors are mostly plasmids or viruses.
However, the use of virus is more predominant while delivering the DNA into recipient’s cells due to their inborn excellence in easily incorporating the genetic material with the foreign one and transferring it into the patient’s genome. But there were always the concerns of developing auto-immune disorders due to aggravated immune responses. In the case of use of plasmids, which is a non-viral circular DNA, as the vector, the risk of developing immune responses get minimized and they can carry comparatively a larger amount of DNA. However, they are regarded as less efficient than the viral vectors in terms of delivering the output at the right venue.
DelveInsight estimates that the Gene therapy pipeline in several areas of discomfort would help in bringing relief to patients who have no standard therapy so far.
Gene therapy has proved itself in curing Beta-thalassemia, cancers due to mutated genes, and several other indications permanently. The Gene therapy pipeline in cancer looks promising with a total of 47 products in development.
Out of these, around 11% products are in Phase III, 43% are in Phase II, 11% are in Phase I, and 17% of the therapies are given IND (Investigational New Drug) status, and around 19% of the gene therapies are still in pre-clinical and discovery stages. Advantagene and Advaxis are the two companies that are leading to their products in the phase III development phase. The highest number of Gene therapy clinical products for cancer is with Takara Bio (three products), and the largest number of non-clinical products is with CZ Biomed (eight products). Advaxis (also known asADXS11-001 (Attenuated Live Listeria Encoding HPV 16 E7 Vaccine) is in various stages of development for the treatment of High-risk locally advanced Cervical Cancer, Persistent or Recurrent Metastatic (Squamous or Non-Squamous Cell) Carcinoma and HPV-associated locally Advanced Anal Cancer.
The identification of critical gene target and delivering the right gene in place of the mutated one are themselves cumbersome task which involves years of Research. After that, the trials to test the efficiency of the therapy is another obstacle in the success of the therapy.
Even after achieving the desired result, fully efficient and safe as it seems, there is a risk of developing autoimmune reactions at later stages.
The halt in the journey of the Gene Therapy came when an 18-year old patient named Jesse Gelsinger undergoing Gene therapy for the treatment of metabolic disorder died during the trials. He developed immune responses and multiple types of leukaemia as a response to the entry of the foreign gene into his genetic makeup. It was one of the unintended consequences that Gene therapy leads to which further delayed the advancement of gene therapy. This has led to the filing of the lawsuit, and adoption of new and stricter regulatory guidelines for the gene therapy in the US.
Gene therapy has a lot more on its platter than this. The cost factor of the therapy has always been a concern among the patients and their caretakers.
However, with advanced medical equipment and innovative bioengineered devices, a more rational understanding will help in performing a more safe and rational therapy using the gene-editing tools.
Development of novel gene delivery systems, gene repair systems and gene expression technologies, systemic therapies may have become a reality but the need to make them available to the common man at prices that are affordable.