In recent years, antibody-drug conjugates (ADCs) have become one of the most promising areas of research in precision oncology. From first-generation ADCs to today's novel site-specific conjugate ADCs, bispecific antibody ADCs, and dual-payload ADCs, the industry is gradually moving from a "drug-ready" phase to a "differentiated competition" phase.
However, in the process of advancing numerous ADC projects, traditional single-toxin ADCs have gradually revealed significant limitations:
● Insufficient adaptability to tumor heterogeneity
● Limited killing effect on resting tumor cell
● Easy to develop drug resistance after long-term use
● Difficulty in DAR optimization
Limited clinical therapeutic window. This is especially true for microtubule inhibitors, such as MMAEs, which are highly effective against rapidly proliferating cells but have weak sensitivity to some low-proliferation tumor cells and are prone to drug resistance due to upregulation of drug efflux pumps.
Therefore, "dual-payload ADCs" are becoming an important and hot research direction in ADC development.
⚪ Multi-mechanism effect: By combining two toxins with different mechanisms, multiple key pathways of tumor cells are destroyed at the same time, enhancing the killing effect.
⚪ Synergistic effect: The two toxins may produce a synergistic effect, further improving the efficacy.
⚪ Reduce the risk of drug resistance: Tumor cells are prone to resistance to a single toxin, and the dual toxin design reduces the risk of drug resistance through multiple mechanisms.
⚪ Multiple strikes: Even if one mechanism fails, another mechanism can still work.
Significant progress has been made in the research of dual-load ADCs. For example, Levengood et al. prepared an ADC containing two different microtubule polymerization inhibitors (MMAE and MMAF), conjugating MMAE and MMAF with a CD30 antibody to exert complementary anticancer activities, and demonstrating significant therapeutic effects in a single-drug-resistant anaplastic large cell lymphoma xenograft model. These results indicate that using two payloads targeting microtubules but with different mechanisms of action can potentially overcome treatment resistance and tumor recurrence caused by cellular heterogeneity (multiple cell cycle states).
For dual-toxin ADCs, the most critical early-stage issues include:
● Which payload combination is optimal?
● Which DAR ratio is better?
● Which antibody has the highest internalization efficiency?
● Which cell model is more sensitive?
● Does a synergistic effect exist between payloads?
Reconstructing the ADC every time would significantly slow down the development process. Therefore, the industry urgently needs a new tool that eliminates the need for formal ADC construction, allows for rapid in vitro assembly, and enables direct cell kill assessment to support high-throughput screening.
Not all studies on dual-load ADCs demonstrate synergistic effects, especially those involving different payload classes. The importance of selecting payloads that complement appropriate mechanisms, ensuring a balanced potency between the two selected payloads, and optimizing DAR values for optimal therapeutic efficacy is crucial.
Currently, there is a lack of detection methods for in vitro kill detection of dual-toxin ADCs; conjugation is required before detection, which is complex and time-consuming. To this end, Critical Point Bio (AlpVHHS) has developed standardized in vitro killing reagents by site-specific conjugation of nanobodies that recognize different locations in the constant region of antibodies, facilitating in vitro assembly and rapid screening of toxins and DAR.
AlpVHHs offers a new generation of Nano-Secondary antibody-drug conjugates with MMAE, MMAF, DXD or PBD for antibody internalization assays.
The use of Nano-Secondary antibody-drμg conjμgates (Nano-Secondary ADCs) in cell-based cytotoxicity assays is a rapid and cost-effective alternative for pre-screening candidate ADC monoclonal antibodies against tumor cells.
Nano-Secondary ADCs are highly specific and minimally toxic to cells in the absence of primary antibodies, and there is no significant change in primary antibody activity when the conjμgated secondary antibody is present.
Functional Cytotoxicity-Based Internalization Screening
● VHH nano-secondary conjugated with potent cytotoxic payloads: MMAE, MMAF, DM1, DXD, Duocarmycin, PBD
● Evaluate internalization-dependent cytotoxicity
● Compare internalization efficiency among multiple antibody candidates
● Support high-throughput screening in tumor cell models
● Ideal for rapid pre-selection of internalizing antibodies before formal ADC development.
Dual-toxin ADCs are becoming an important direction for next-generation ADC research and development, with their core value lying in:
● enhancing anti-tumor efficacy
● overcoming drug resistance
● improving heterogeneity coverage
● prolonging treatment response
However, traditional ADC construction and screening processes are complex and time-consuming, severely limiting the efficiency of early exploration. AlpVHHs' Nano-secondary ADC platform, through a nanobody-based site-specific conjugation strategy, achieves:
● rapid in vitro assembly
● multi-payload combination validation
● rapid DAR screening
● functional cell-killing detection
providing an efficient and standardized new tool for dual-toxin ADC development.
Code | Description | Applications | Size |
023-102-101 | Internalization Test | 100 ug | |
023-101-101 | Internalization Test | 100 ug | |
023-102-102 | Internalization Test | 100 ug | |
023-101-102 | Internalization Test | 100 ug | |
023-102-103 | Internalization Test | 100 ug | |
023-101-103 | Internalization Test | 100 ug | |
023-102-104 | Internalization Test | 100 ug | |
023-101-104 | Internalization Test | 100 ug |
Code | Description | Applications | Size |
001-106-101 | Internalization Test | 100 ug | |
001-101-102 | Internalization Test | 100 ug | |
001-106-102 | Internalization Test | 100 ug | |
001-101-101 | Internalization Test | 100 ug | |
001-106-103 | Internalization Test | 100 ug | |
001-101-103 | Internalization Test | 100 ug | |
001-106-104 | Internalization Test | 100 ug | |
001-101-104 | Internalization Test | 100 ug |
