Science of biologics & the

characteristics of biotech

production process

Andres F. Zuluaga, MD, MSc

Head. Department of Pharmacology & Toxicology

University of Antioquia

Medical School

azuluaga@medicina.udea.edu.co

Why are we here?Importance of Biologic Drugs

MODERN BIOTECHNOLOGIES & THE DISCOVERY OF DNA MANIPULATION

Biotechnology:

The commercial

application of living

organisms or their

products (Bio-), which

involves the deliberate

manipulation of their DNA

molecules (Technology) to

solve problems or make

useful products.

INNOVATION (R&D) NEW PRODUCT BENEFITS

Source: http://www.accessexcellence.com/RC/VL/GG/biotechnology.html

Applications of Biotech to Healthcare

� Diagnosis

� Therapy

� Vaccination

� DNA testing

� Diagnostic kits

� Drugs & novel therapies

� DNA fingerprinting

For drugs (to treat or to prevent): Biopharmaceuticals

EJHP Practice Vol 13 2007/1

Pavlovic M. Horm Res 2008;69:14-21

Vaccines, blood products or derivates (including heparins), hyperimmune

serum, hormones (rhGH), toxins, monoclonal antibodies, peptides,

cellular therapy.

Time-line of Biopharmaceuticals

� Establishment of an alliance (“merger”) between the start-up

biotech companies (technical expertise) and big pharmaceutical

companies (pharmaceutical experience) in 1980s –> Biotech

sector

� i.e. Genentech & Eli Lilly: development of recombinant human insulin,

clinical trials and large-scale marketing (Humulin)

� The vast majority of recombinant proteins are produced in E. coli, S.

cerevisiae or in animal cell lines (Chinese hamster ovary (CHO) or

baby hamster kidney (BHK) cell lines). The use of additional modern

biotechnologies such as protein engineering in conjunction with an

increased understanding of structure-function relation of proteins has

facilitated the development of more potent and safe B&B drugs..

PROTEIN ENGINEERING COMMONLY USED TO PRODUCE BIOPHARMACEUTICALS

1. Alteration of single amino acid

residues at specific sites.

2. Insertion or deletion of a single

amino acid residue.

3. Alteration or deletion of an entire

domain.

4. Generation of a novel fusion protein.

ISSUE #1: PATENT PROTECTION FOR MANY 1ST GEN. BIOPHARMACEUTICALS HAS NOW COME/IS COMING TO END.

ISSUE #2: CHEMICAL VS BIOLOGICAL DRUGS: WHICH IS BETTER?10-Year Trends in Major Drug and Biological

Product Submissions to FDA

Novel chemical structure

Biological drugs

ISSUE #3: THERE IS A COMPLEX CRITICAL PATH FOR MEDICAL PRODUCTS

Why are Biotech products expensive?

High R&D + high Return = high Risk

Which is/are the difference(s) with Chemical drugs?

Características Chemical Biologic

Active ingredient (MW)Small molecules (tipically

<500-1000 kDa)

Large macromolecules (peptides ,

often >1000 kDa)

Manufacture

Typically chemically

synthesized with high degree

of purity and

characterization. Can be

analyzed from a structure-

function perspective

Inherent Heterogeneity. Product

Process

Relationship. Activity may be affected

by minor changes in bioprocessing and

post-translational

modifications.

Production

A well defined synthetic

pathway that can be scaled

to large quantities

Potential for complex production

process, scale up, purity, batch

variability issues. Process yields can be

small.

Pharmaceutical forms

Variable (oral, topical, etc),

concentration & potency can

be established

Usually injectable forms. Potency

more difficult to quantify.

Comparison criteria for

version different to

innovator

Bioequivalency (AUC)Preclinical test, PK, PD, clinical trials to

assess safety & eficacy, PV

Immunogenicity

Potential

Usually too small to be

considered as immunogenic

Immunogenic potential is high for

macromolecules that are recognized as

foreign

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Why Are Biotechnology Products Different From Simple Organic Chemicals?

Synthetic Drugs

Small molecules

Easy synthesis

� Aspirin

� Oligopeptides

Hemi-synthesis

Need of active stereo-isomers

� Steroids

� Anticancer

� Antimetabolites

� Cyclosporin

Extraction Biologicals

Complex & rare molecules

Animal source possible

� Insulin

� Heparins

Human source necessary

� HGH

� Coag. Factors

� Albumin

Implies a purification Process prior to human use.

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Manufacturing Processes Are Different

Biotech Products

� Produced by purification

� Starting material variable

� Many in-process tests

� Complex End-product tests

� Process is product-specific

� Batch sizes are small (g or kg of finished product)

Conventional drugs

� Produced by formulation

� Starting material defined

� Few in-process tests

� End-product tests simple

� Process is product type specific (generalizations possible)

Molecular identity can be tested only for Conventional drugs

Ten key questions that drug regulatory agencies have to solve to license a biologic drug

1. Does the manufacturing process or materials raise

concerns about product safety (impurities, infectious

agents, lack of stability)?

2. What is known about the product and the purported

mechanism of action? (does this mechanism raise

concerns about impact on normal organs/tissues?)

3. Is there evidence in the laboratory and animal

studies that the product has the predicted action? If

not, why not?

Ten key questions that drug regulatory agencies have to solve to license a biologic drug

4. Do preclinical data (or foreign experience in humans)

support the safety of:

� Starting dose, schedule, route of administration, duration of

exposure, proposed rate of dose escalation

5. Does the protocol appropriately monitor for toxicities (given

concerns based on chemical structure, toxicologic data or

prior human experience)?, Are risks acceptable for the

population to be studied?

6. Are there formulation issues, e.g., same formulation studied

in animals, toxic impurities?

7. Have phase 1 studies identified an optimal dose (safety and

activity) or should more dose exploration studies be done?

Ten key questions that drug regulatory agencies have to solve to license a biologic drug

8. Do available activity data support efficacy assumptions

underlying Phase 3 (registration) trials?

9. Are trials designed to collect efficacy data; sources of

bias minimized?

10. Can be their safety monitored after massive use,

including the immune potential ? (i.e.

pharmacovigilance program)

3 remarks about B&B

�Are they safe?

�Are they better than chemical

drugs on efficacy?

�Are biologic generics (biosimilars)

really equal (identical)?

They are really equal?

Bio-similar?

- Small-molecule drugs : generic form can be marketed if their

therapeutic equivalence to the original drug is proved

� pharmaceutical equivalence ( identical active substance) and bioequivalence ( comparable pharmacokinetics)

� no clinical efficacy and safety test

- Therapeutic proteins : the generic approach can not be applied to copies of therapeutic proteins because of complexity

� impossible to prove two protein products to be identical

� comprehensive clinical data : clinical equivalence

� approval by regulatory authority

� marketing

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How complex can be the process?Five Features of the Biotechnology Production Process

In summary, to produce a biologic drug we need:

1. Expression system of the gene

2. Production system compatible with the microorganism

3. Purification system

4. Nature of the active product

5. Pharmaceutical formulation and presentation

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Five Features For a Biotechnology Drug1. Expression System: Vector + Host

Identify, isolate and clone the gene coding for the desired protein

Construct a vector containing:� The gene

� The expression controls (promoter, secretion signal…)

Insert the vector into the selected micro-organism� Escherichia coli

� Saccharomyces cerevisiae

� Mammalian cells

� Genetically modified plants

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Expression System: Vector Construction + Host

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Five Features For a Biotechnology Drug2. The Production System

Purpose

� Optimize survival conditions for the genetically modified microorganism

� So that it produces the desired protein

� With acceptable yield

Materials & Methods

� Selection of cell culture media

� Selection of culture conditions

� Selection of culture equipment: i.e. fermenter

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Five Features For a Biotechnology Drug3. The Purification System

Purpose

� Extract protein from a complex growth medium

� Achieve close to 100% purity

� Without altering the protein

Materials & Methods

� Sequence of purification steps

� Filtration/ultrafiltration

� Precipitation/resolubilization

� Chromatography (ion-exchange, affinity, etc.)

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Five Features For a Biotechnology Drug4. Nature of Active Product

Proteins

� Chains of amino-acids

� Sequence of amino-acids encoded by genes

� Folded into 3-D conformation

� To obtain biological activity

� Host-dependent post-translational modifications (sugars…)

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Five Features For a Biotechnology Drug5. Pharmaceutical Formulation and Presentation

Purpose

� Maintain biological activity

� By keeping active protein conformation in solution

Materials & Methods

� Stabilization (albumin, glycerol)

� Storage at low temperature

Aoki KR. Int Ophthalmol Clin 2005;45(3):25-37

� Drug names of botulinum toxin products have changed to highlight the

different dose/potency ratios and emphasize that they are not

interchangeable

CARJ1

Slide 30

CARJ1 Texto en Español! traduje el último párrafoCARJ; 20/10/2010

Clinical Pharmacology

Immunogenicity: key-point for a good comparison of biopharmaceuticals

Clinical Pharmacology

Immunogenicity: key-point for a good comparison of biopharmaceuticals

http://www.nytimes.com/2008/04/30/health/policy/30heparin.html

Conclusions

� Biologics are radically different to chemical drugs

in terms of molecular nature and size,

manufacturing process, purification and

immunogenicity, so they require different criteria

for clinical approval, specially in the case of

biosimilars, a fact that national drug regulatory

agencies are just beginning to recognize.

� Production of biologic drugs is so complex and

variation-prone that there is no

interchangeability, and each product has to

demonstrate its own efficacy and safety