PEPTIDES & PROTEINS material has imaging ( diagnostic ) or therapeutic properties .
A common ‘ pairing ’ of radio isotopes is 68Ga for diagnostic purposes and 177Lu for the therapeutic . This is quite different from conventional radiotherapy , which involves using high-energy radiation to target an area in the body , but not specific celltypes or receptors .
Peptide cleavage in an Almac Sciences lab
Peptides as targeting ligands
One of the keys to success with theranostics is selecting an effective targeting agent . Different types of molecules may be considered for this task , such as small molecules , peptides , or antibodies . Peptides have emerged as highly effective targeting agents in theranostics .
Their unique properties make them ideal for this role . Firstly , they can be designed to bind with high specificity and affinity to target molecules or receptors on cancer cells . This ensures that the therapeutic agent is delivered precisely to the tumour site , minimising damage to healthy tissues .
In addition , the small size of peptides allows them to penetrate tissues more effectively than larger molecules , such as antibodies . This enhances their ability to reach and bind to target cells within the tumour microenvironment .
Peptides are also rapidly cleared from the bloodstream , reducing the risk of systemic toxicity . This property is particularly important in theranostics , where minimising exposure to healthy tissues is crucial
Finally , peptides can be easily synthesised and modified to enhance their stability , binding affinity , and therapeutic efficacy . Chemical modifications can also be used to improve their resistance to enzymatic degradation , further increasing their effectiveness as targeting agents .
Experience to date
As a CDMO , Almac has been involved with the production of radio-imaging precursors , and there are numerous aspects of manufacturing that are taken into account . The manufacturing scale tends to be modest ; with very low dosage , a few grams of material goes a very long way . This means that it can be tricky to build in-depth manufacturing experience over multiple batches .
That aside , the entities are treated like a standard API by the regulatory authorities , and despite the small batch sizes , the same rigour around process understanding and analytical controls is required . Some allowances are made , however . In the EU at least , the microdosing of chemical precursors for radiopharmaceuticals is considered such that reporting and identification thresholds are more relaxed compared to standard synthetic peptide APIs . 2
One further challenge with these molecules is that they are typically manufactured metal-free with complexation of the radioactive element performed at the site of dosage ( e . g . hospital ). This means that additional controls are required during the manufacture to avoid unwanted metal chelation or complexation , which in turn means tighter control on the raw materials and equipment used for the process is required .
Conclusion & future directions
The field of theranostics is rapidly evolving , with ongoing research focused on developing new targeting agents , improving imaging techniques and expanding the range of treatable cancers . Advances in molecular biology , nanotechnology and radiochemistry are expected to drive further innovations in theranostics , enhancing its precision and effectiveness .
Theranostics represents a paradigm shift in personalised medicine , offering a more precise and effective approach to diagnosing and treating diseases . Peptides , with their high specificity , small size , rapid clearance , ease of synthesis and versatility , are proving to be invaluable tools in this field . As research continues to advance , theranostics holds great promise for improving patient outcomes and transforming the landscape of cancer treatment . ●
References 1 : Global Data , 2025 . 2 : European Pharmacopoeia ( EP ) 10.0 , Chemical Precursors for Radiopharmaceutical Preparations .
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Alastair Hay
VP , PEPTIDES
ALMAC SCIENCES alastair . hay @ almacgroup . com www . almacgroup . com
MAR / APR 2025 SPECCHEMONLINE . COM
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