Gene Therapy, Enabling Patient-specific Treatment
Insulin
Inspires Diabetes Treatment
With India emerging as
the diabetes
capital of the world, pharmaceutical companies are racing ahead to grab
a piece of the pie with new anti-diabetic drugs
Insulin therapy has evolved in the last century from purified bovine or
porcine insulin to biosynthetic human insulin to recombinant human
insulin and eventually to recombinant insulin analogs as the third
generation of human insulin. Indian companies are also
putting in
efforts to capture the market amid stiff competition from the
established multinational companies such as Novo Nordisk, Eli Lilly and
Aventis Pasteur. Wockhardt was the first Indian company to launch the
country’s indigenously developed recombinant human insulin
under
the brand Wosulin. A year later Bangalore-based Biocon Ltd announced
the launch of Insugen, the new generation bio-insulin in November
2004. Shreya Life Sciences, the Indian arm of Moscow-based
Shreya
Corporation too launched human insulin under the brand name Recosulin
in December 2004, exactly a month after the launch of Insugen.
Besides Indian companies, Eli Lilly entered the Indian insulin market a
decade ago in 1995 with the brand Huminsulin. Before that Novo Nordisk
launched its human insulin product and went on to introduce insulin
analogs under the brand NovoMix 30, a premixed insulin analogue and
NovoRapid, a rapid acting insulin analogue, for the first time in
India. In August 2005, Eli Lilly and Company (India) too launched its
insulin analogs under the brand Humalog Mix 25, 50. In 2007,
Eli
Lilly launched Byetta(exenatide), a drug derived from the saliva of the
Gila monster, for the treatment of type 2 diabetes mellitus. Byetta is
the first in a new category of medicines known as incretin mimetics,
which is approved as adjunctive therapy to improve blood sugar level in
patients with type 2 diabetes.
The year 2008 saw the launch of a Januvia (sitagliptin) by MSD
Pharmaceuticals, the first and only prescription medication in a new
class of drugs known as dipeptidyl peptidase-4 inhibitors (DPP-4
inhibitors), which enhance the body’s own ability to lower
blood
sugar when it is elevated. Very recently Wockhardt has
launched a
new insulin, Glaritus, a generic version of Sanofi-Aventis’
Lantus, which is a recombinant long-acting human insulin analogue.
Glaritus is available as reusable and disposable pen delivery device,
which is one of the most preferred modes of insulin injection across
the globe today. In a major breakthrough, Mumbai-based Shreya Life
Sciences, in collaboration with the US-based Generex Biotechnology
Corporation, has announced the launch of world’s first buccal
insulin spray under the brand name of Oral-Recosulin in India for the
treatment of type-1 and type-2 diabetes. Last year has seen two new
classes of drugs entering the market, both of which work on the
incretin system, injectable glucagon-like peptide-1 (GLP-1) agonists
and oral dipeptidyl peptidase-4 (DPP-4) inhibitors. GLP-1 agonists,
also known as incretin mimetics, stimulate insulin secretions from beta
cells in the pancreas in response to food intake, in a glucose
dependent manner. DPP-4 inhibitors inhibit the DPP-4 enzyme, which
results in an increase in circulation of the incretin hormone, GLP-1.
Future
The worldwide market of the major human insulin products in 2007 was
$10 billion. Insulin analogs posted double digit sales growth worldwide
due to successive replacement of second generation human insulin. As
per ORG IMS, the current market for analogues in India is Rs 120 crore
with a growth rate of 37 percent per annum. The Indian diabetic market
is estimated to be around $355 million with a growth rate of 20.6
percent as per the ORG IMS. Human insulin market is $107
million
with a growth rate of 23.9 percent while the oral antidiabetic market
is $248 million and is growing at the rate of 19.2 percent.
There
are various devices used for delivering insulin, including syringes,
pens, pumps, needle-free injectors and inhalers.
According to estimates by 2025, nearly one-third of total diabetes
patients will be from India and China, both of which have fledgling.
The next generations of insulin will be ‘tailored’
insulin,
oral insulin and other long-acting insulins for injection with drug
delivery solutions, that aims at optimized pharmacokinetic profiles in
order to avoid hypo- and hyper-glycemic episodes. After the failure of
Pfizer’s inhaled insulin Exubera, most of the R&D
efforts are
now made on oral insulin products. Mannkind’s Afresa, an
inhaled
insulin product that has recently completed phase-III trials, and
Generex Oral-lyn from Generex Biotechnology, a buccal spray formulation
in phase-III in the US has recently been approved for marketing in
Ecuador, India and Lebanon.
Novo Nordisk plans to launch its anti-diabetes drug Liraglutide in
India by 2010, which will treat diabetes faster than insulin. The drug
has completed phase-III clinical trials successfully in India.
Liraglutide is an analog which has revealed better control of blood
sugar compared with insulin therapy in diabetes patients. It reduces
hypoglycaemia, the sudden lowering of blood sugar levels, by increasing
insulin secretion and delaying gastric emptying. Biocon is developing
IN-105, a conjugated insulin molecule that is orally delivered and
targeted towards the treatment of diabetes.
Biocon’s R&D group has successfully developed a
tablet for
oral delivery of IN-105, its formulation carefully selected to give
consistent absorption and glucodynamic effect. In the clinic, this
molecule has completed phase-I trials. The results of the dose range
finding of phase-II trials were presented at European Association for
the Study of Diabetes (EASD), Rome in September 2008, and the product
is expected to hit the market in 2010. Its other product, Nasulin, an
intra-nasal insulin spray, is being co-developed with Bentley
Pharmaceuticals Inc. and shall also hit the markets the same year.
In the future, insulin may be delivered by implanted or
transferral systems. Insulin pumps are already popular in the US, where
the small mobile phone-size devices which send a continuous flow of
insulin into the body through a hypodermic tip. Implantable insulin
pumps are currently under development in Europe and the US. Another
future option for insulin administration may be the intranasal route
that offers ease of delivery and fast absorption time. In addition,
gene therapy and the potential for implanting insulin-producing
pancreatic cells are also being researched.
With diabetes now the fifth leading cause of death across developed
markets and figures from PricewaterhouseCoopers (PwC) suggesting the
disease is forecast to grow by 7.1 percent across the globe by 2013,
the market for once-a-day drug delivery and non-invasive drug delivery
systems continues to offer significant potential for expansion. India
is predicted to lead the way with 73.5 million people expected to have
the disease by 2025. As such, companies like US-based Eli Lilly by
announcing a joint venture with Indian company Jubilant Organisms in
October 2008, are looking to secure their place in the market. The next
few years promise dramatic change in the treatment of diabetes, much of
which will be driven by rapidly developing technology. Every company is
striving for two common goals, patient convenience and better control
of the disease.
History
In 1921 Canadian research team led by Dr. Fredrick G Banting discovered
insulin extracted from the islets of animal pancreas. Later, bovine
insulin was given to humans by injection in 1922. In 1936, protamine, a
low-weight protein is used to develop a slow-release insulin. In 1950
yet another approach led to the development of presently available
Isophane NPH (Neutral Protamine Hagedorn) insulin, which is also bound
to protamine. It was only in 1978, scientists from the biotechnology
corporation Genentech in San Francisco, California, used a genetically
manipulated plasmid of E. coli bacteria to produce insulin with the
same amino sequence as seen in humans. The race to mass produce
‘human’ insulin using gene technology was won by
Eli Lilly
in 1982 when the Food and Drug Administration (FDA) approved Humulin-R
(rapid) and Humulin-N (NPH) for the US market. This was followed by
Novo’s semisynthetic insulins, Actrapid HM and Monotard HM.
Since
1996, different insulin analogues have been introduced worldwide such
as Humalog from Eli Lilly, Lantus and Apidra from Aventis, Levemir and
NovoRapid from Novo Nordisk to name a few. |
Shalini Gupta