Here are some key features that distinguish between ADC payloads and conventional payloads:
- Although small compounds typical ADC payloads have substantial harmful side effects like PBD, they also function effectively for medications. Conversely, some novel payloads consist of tiny compounds with little pharmacological impact and negative side effects such as Dxd.
- Conventional ADC payloads mostly include microtubule inhibitors and DNA damaging compounds, whereas innovative ADC payloads offer a wider range of target types, more options, and distinct modes of action in comparison to traditional payloads. For example, the use of immune stimulants in antibody-drug conjugates (ADCs) as payloads.
- Conventional ADC has complex structures which makes it difficult to manufacture small molecule payloads and hence it requires advanced technology. To reduce synthesis-related difficulties and increase market attractiveness, ADC payloads are typically small molecules with low molecular weights and simple structures.
- The typical payload for an ADC is a single small molecular molecule that is directly attached to the antibody through a linker. On the other side, the more sophisticated ADC can combine various payload types, leading to a synergistic effect where the whole impact exceeds the individual components.
Approaches to minimize ADC limitations:
Optimizing the payload by altering its physicochemical features, particularly its polarity, can help address some challenges encountered in the setup and utilization of ADCs. Linking an excessive number of hydrophobic payloads might modify the structural stability of the antibody, enhance its propensity to assemble and precipitate, and eventually impact its maximum drug-to-antibody ratio (DAR), persistence in plasma, bystanders effect, and other factors. Hydrophobic payloads have the ability to easily pass through the cell membrane and eliminate nearby tumor cells that lack the specific antigen through the bystander effect. On the other hand, hydrophilic payloads are released from tumor cells at a slower pace. Toxic side effects plague most antibody-drug conjugates (ADCs). These hazardous side effects are mostly caused by the payload and affect rapidly dividing healthy cells including lymphocytes and gastrointestinal responses. Thus, one can choose a payload with low molecular weight, good tissue penetration, and a short half-life. It can quickly accumulate in the desired region and kill cancer cells after discharge. In addition, bloodstream pharmaceutical molecules can be efficiently removed, reducing systemic side effects. Altering key target sites and adding or removing better-tolerated drugs is also possible.
Requirements for pharmacokinetic (PK) study:
We identified four conditions for ADC PK studythrough a thorough literature review, pharmacokinetic analysis of authorized ADC drugs, and research summary:
1. Proficient in conductingPK studyfor small and large drugs is essential.
2. ADME and bioanalysis require extensive capabilities and facilities, including large and small animal studies, compound analysis, in vitro drug-drug interaction studies, metabolite identification, and radiolabeled ADME handling.
The pharmacokinetic (PK) method and protocols must be tailored to the composition of the antibody-drug conjugate (ADC) and the efficacy and safety needs of innovative drugs.
4. The ADCPK study requires strong project management skills and the ability to collaborate across departments.
The ADC pk study has four key domains: in vitro DDI, ADME, PK, and bioanalysis. These criteria are crucial to drug discovery, pre-clinical development, and clinical trials.
