A brief introduction to the concepts of large molecules/small molecules in biopharmaceuticals:

$XTALPI(02228.HK) Explain these concepts (small molecules, large molecules, ADC, molecular glue) in simple language, using examples and analogies, suitable for professionals without a biomedical background to quickly understand. As a shareholder, in case you need to brag, without understanding the professional terms, it always feels like something is missing. Here's what you need.

https://mp.weixin.qq.com/s/CRK3NOaM370PSu12U_Cxag

🧬 1. What are "small molecule" drugs?

✅ Simple understanding:

Imagine swallowing a pill. The main ingredient in this pill is very, very small, as small as a tiny screw, and can travel into various cells and organs of your body, reaching the target (such as a disease-causing protein) and "blocking" it to stop its activity.

These are called small molecule drugs.

🧪 Characteristics:

Feature	Description
Small molecular weight	Usually < 900 daltons
Chemical synthesis	Can be manufactured in the lab through chemical reactions
Oral administration	Most can be taken as tablets or capsules
Fast absorption	Easily enters cells and spreads throughout the body

📌 Examples:

Aspirin (painkiller)

Statins (cholesterol-lowering drugs)

Imatinib (cancer drug Gleevec)

🧬 2. What are "large molecule" drugs?

✅ Simple understanding:

Compared to the "small molecule" "screw," large molecule drugs are as big as a small boat, more complex, more advanced, and generally "cultivated" from biological organisms (such as cells).

They are often proteins or antibodies that can accurately recognize "enemies" in your body (such as viruses or cancer cells) and stop their activity.

🧪 Characteristics:

Feature	Description
Large molecular weight	Usually > 10,000 daltons, hundreds of times larger than "small molecules"
Biopharmaceutical	Cannot be chemically synthesized; must be cultivated from cells
Cannot be taken orally	Usually administered by injection or infusion (otherwise, stomach acid will "digest" them)
Highly targeted	More like a "missile"—specifically targeting certain points

📌 Examples:

Insulin (for diabetes)

Trastuzumab (Herceptin, for breast cancer)

COVID-19 vaccines (mRNA or antibody-based vaccines are also large molecules)

🔗 3. What is ADC (antibody-drug conjugate)?

✅ Simple understanding:

It attaches "small molecule drugs" (poison) to "large molecule antibodies" (missiles), specifically delivering them to cancer cells or diseased areas to release the drug.

It's like:

Using antibodies as "missile guidance heads" to identify targets

Using small molecule drugs as "bombs" for precise delivery

🧪 Characteristics:

Feature	Description
High precision	Only targets cancer cells, avoiding harm to normal cells
High toxicity	The small molecule part can be very toxic because it doesn't spread randomly
Complex manufacturing	Higher production difficulty, but strong efficacy and good targeting

📌 Examples:

Enhertu

Roche's Kadcyla

🧲 4. What is "molecular glue"?

✅ Simple understanding:

It doesn't traditionally "block" disease proteins but acts like glue, sticking to the disease protein and dragging it away to be "destroyed." It doesn't directly inhibit function but causes the entire protein to be degraded!

This is a very popular new mechanism in recent years:

Not "shooting the target" but "calling security to remove the target"

It uses the body's own protein degradation system (called the "ubiquitin-proteasome system") to clear abnormal proteins

📌 Examples:

Molecular glue is a representative of Degrader drugs, such as:

C4 Therapeutics

Arvinas products

🧠 Summary comparison table:

Category	What's it like?	Composition	Advantages	Examples
Small molecule	Screw	Small chemically synthesized compounds	Oral administration, cheap	Aspirin, Imatinib
Large molecule	Missile	Proteins, antibodies, etc.	Strong targeting, precise	Insulin, antibody drugs
ADC	Missile + bomb	Antibody + small molecule drug	Precise delivery, no collateral damage	Enhertu, Kadcyla
Molecular glue	Glue + police	Recruits security to clear proteins	Innovative mechanism, broad action	ARV-110, etc.

🧬 Summary of Jingtai Technology's technical advantages:

Rare capability to simultaneously develop all four types of drugs;

Uses AI + robotic experiments to improve drug discovery efficiency and reduce failure rates;

Covers everything from "molecule design" to "toxicity/efficacy prediction" to "synthesis route planning";

Has rich real-world projects and data to feed AI models, making them smarter over time.