Prodrugs, Antibody-drug conjugates and Biobetters



A prodrug is a medication or compound that, after administration, is metabolized (i.e., converted within the body) into a pharmacologically active drug. Prodrugs are classified into two major types, based on how the body converts the prodrug into the final active drug form, either intra- or extracellularly.

Prodrugs are eligible for the simplified regulatory approval processes: 505(b)(2) in the US or hybrid application in the EU, partly relying on data from the originator product.

Antibody-drug conjugates (ADCs) 

Antibody-drug conjugates (ADCs) are targeted drugs that deliver chemotherapeutics (cell toxins) directly to the patient's tumor cells. In order to accomplish this, the toxin needs to be linked to a targeting antibody via a degradable chemical linker.

After injection the antibody conjugate circulates in the bloodstream until the antibody has found specific structures on the cancer cells to which it can bind. As long as the chemotherapeutic is linked to the antibody it is inactive but after binding to the cell surface, the entire conjugate is taken up by the cell and the linker is broken down so that the toxin can act inside the cancer cell. This reduces the side effects compared with conventional treatment, and this has also enabled the use of chemotherapeutics with higher toxicity than previously possible.


A biobetter is a biological that has been structurally and/or functionally altered to achieve an improved or a different clinical performance compared to an already approved original (innovator) biological product. Biobetters aim for the same target (e.g. receptor, enzyme) as the innovator product. Alterations used in the design of biobetters usually include chemical modification (e.g. PEGylation) or novel formulation (e.g. novel route of administration, modified release).

Improvements may result in longer half-life (enabling less frequent dosing), better efficacy and/or safety or reduced immunogenicity. Depending on their level of innovation and how well they meet a defined unmet medical need, biobetters may obtain patent and data exclusivity.

QuiaPEG Pharmaceuticals Holding AB

Virdings Allé 32 B
754 50 Uppsala
+46 (0) 70 693 12 53

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