Preclinical Evaluation of<sup>111</sup>In-Labeled PEGylated Maytansine Nimotuzumab Drug Conjugates in EGFR-Positive Cancer Models
Bibliographic record
Abstract
Epidermal growth factor receptor I (EGFR) is overexpressed in most cancers of epithelial origin. Antibody drug conjugates (ADCs) with PEGylated-maytansine (PEG-DM1) show promise in vitro and in vivo. However, in vivo biodistribution data for ADCs with PEG-DM1 have not been reported. Development of methods to understand the real-time in vivo behavior of these ADCs is needed to move these compounds to the clinic. Methods: Here we have used noninvasive small-animal SPECT/CT imaging and ex vivo biodistribution to understand the in vivo behavior of PEG 6 -DM1 ADCs. We developed nimotuzumab ADCs conjugated to PEG 6 -DM1. We generated immunoconjugates with low (nimotuzumab-PEG 6 -DM1-Low) and high (nimotuzumab-PEG 6 -DM1-High) drug-to-antibody ratios. The drug-to-antibody of nimotuzumab-PEG 6 -DM1-Low and nimotuzumab-PEG 6 -DM1-High was 3.5 and 7.3, respectively. Quality control was performed using ultraviolet spectrophotometry, size-exclusion high-performance liquid chromatography, bioanalyzer, biolayer interferometry, and flow cytometry in EGFR-positive DLD-1 cells. These immunoconjugates were conjugated with DOTA and radiolabeled with 111 In. The in vitro binding and internalization rates of 111 In-nimotuzumab, 111 In-nimotuzumab-PEG 6 -DM1-Low, and 111 In-nimotuzumab-PEG 6 -DM1-High were characterized. Furthermore, the pharmacokinetics, biodistribution, and imaging characteristics were evaluated in normal and DLD-1 tumor-bearing mice. Results: Flow cytometry and biolayer interferometry showed a trend toward decreasing EGFR affinity with increasing number of PEG 6 -DM1 on the antibody. Despite the lower overall cellular binding of the PEG 6 -DM1 radioimmunoconjugates, internalization was higher for PEG 6 -DM1 ADCs than for the non-PEGylated ADC in the following order: 111 In-nimotuzumab-PEG 6 -DM1-High . 111 Innimotuzumab-PEG 6 -DM1-Low . 111 In-nimotuzumab. Nuclear uptake of 111 In-nimotuzumab-PEG 6 -DM1-High was 4.4-fold higher than 111 In-nimotuzumab. Pharmacokinetics and biodistribution showed that 111 In-nimotuzumab-PEG 6 -DM1-High had the slowest blood and whole-body clearance rate. Uptake in DLD-1 tumors of 111 In-nimotuzumab was similar to 111 In-nimotuzumab-PEG 6 -DM1-Low but was significantly higher than for 111 In-nimotuzumab-PEG 6 -DM1-High. Tumor-to-background ratios for 111 In-nimotuzumab and 111 Innimotuzumab-PEG 6 -DM1-Low were higher than for 111 In-nimotuzumab-PEG 6 -DM1-High. Conclusion: The results show that conjugation of multiple PEG 6 -DM1 reduces the affinity for EGFR in vitro. However, the reduced affinity is counteracted by the high internalization rate of constructs with PEG 6 -DM1 ADCs in vitro. The decreased affinity resulted in low tumor uptake of 111 In-nimotuzumab-PEG 6 -DM1-High, with a slow overall whole-body clearance rate. These data provide insights for evaluating the pharmacokinetics and normal -tissue toxicity and in determining dosing rate of PEGylated ADCs.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.006 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.003 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".