Biopharmaceuticals (Pharmacobiotechnology Based Drugs)

2.6. Biopharmaceuticals (Pharmacobiotechnology Based Drugs)

Biopharmaceuticals may be defined as — ‘complex macromolecules derived from recombinant DNA technology, cell fusion or such processes that essentially involve genetic manipulation.

Examples : Biopharmaceuticals include : recombinant proteins, therapeutic monoclonal anti- bodies (MABs) and nucleic acid-based therapeutics (viz., DNA-based medicines), genetically engi- neered vaccines, and gene therapy vectors.

In 1982, the first and foremost drug ever produced via genetic engineering was the wonder drug known as ‘human insulin’. Almost within a span of two decades (by mid-2000), eighty four biopharmaceuticals were duly approved for marketing by US-FDA, of which around forty were intro- duced between mid-1997 and mid-2000. In USA, the worldwide sales of these specialized drugs shot upto USD 15 billion by the end of 1998. Interestingly, USA distinctly represented almost 46% of the market in comparison to mere 36% for the usual conventional drugs by virtue of the following cardinal factors, such as :

earlier regulatory approval (US-FDA) easier market acceptance much greater pricing flexibility than other countries on the globe.

No doubt, the biopharmaceuticals do represent rather small 5% of the world’s prescription drug sales, they normally account for six of the world’s top 50 best selling drugs. It is quite important to have

a clear and distinct concept in mind between the following two important aspects, namely : (a) biotechnology — as a new process technology, and

(b) biotechnology — as a ‘drug discovery’ research tool. Obviously, the first makes use of ‘genetic engineering’ almost exclusively in the specialized and

critical manufacture of only large molecular weight drugs e.g., insulin, vaccine etc., which are rather difficult and impracticable to be produced either by synthesis or by extraction.

Evidently, the second aspect involves the meticulous search for newer therapeutic targets, with

a large emphasis on the focus upon certain specific small molecular weight drugs which could easily and conveniently interact against those targets by the help of biotechnology based research tools, such as :

• cloned receptors as screens, and • gene knock-out technologies

in the most specialized formation of transgenic organisms to determine protein function. It is indeed pertinent to mention at this point in time that the pharmaceutical industry across the

globe shall definitely hold and maintain its ever dominant status with regard to the discovery of ‘small molecules’ via the meticulous application of biotechnology in drug discovery ; whereas, the conceptu-

alized ideas, development, and ultimate manufacture of highly specific protein-based drugs certainly need an altogether completely different degree of core competencies.

namely : (a) Approved medicines, and

ADVENT OF BIOTECHNOLOGY

The two different categories of biotechnology medicines shall be exemplified in the sections that follows* :

Approved Medicines : A few typical examples of ‘approved medicines’ by several drug au- thorities are enumerated below :

S.No. Name of Product

Company

Indication (s)

1 Activase (R)

Genentech

Acute myocardinal infarction ;

(Alteplase)

(S. San Francisco CA) Pulmonary embolism ;

2 Epogen (R)

Amgen

Anemias of chronic renal disease ;

(Epoctin alfa)

(Thousand Oaks, CA)

AIDS ; Cancer chemotherapy ;

3 Humulin (R)

Eli-Lilly

Diabetes ;

(Human Insulin)

(Indianapolis, IN)

4 Leukine (R)

Immunex

Myeloid recognition after bone marrow

(Sargramostim)

(Seattle, WA)

plantation ;

5 Recombivax HB (R)

Hepatitis B prevention ; (Hepatitis B vaccine) (Rahway, NJ)

Merck

Medicines Under Development : Certain specific examples of such ‘medicines under devel-

opment’ are as stated under :

S.No. Name of Product

Company

Indication (s)

1 Recombinant human platelet derived Chiron Wound healing ;

growth factor — BB (PDGF)

(Emeryville, CA)

2 Immuneron

Biogen

Multiple sclerosis ;

(Interferon gamma)

(Cambridge MA)

3 Cento RX

Centocor

Anti-platelet prevention

(Mab)

(Malvern, PA)

of blood clots ;

4 Myoscint

Centocor

Cardiac imaging agents ;

(Mifarmonab)

(Malvern, PA)

5 Vax-Syn (R) HIV-1

Micro Gene Sys

AIDS ;

(gp 160)

(Menden, CT)