| Modality/compound | Target/mechanism | Evidence of involvement of β/δ core or EIF2B4 | Application area | Development stage | Key quantitative data | URL | Evidence IDs |
|---|---|---|---|---|---|---|---|
| ISRIB | Small-molecule eIF2B activator; binds the symmetric interface of eIF2B and stabilizes the active A-state, making eIF2B GEF activity less sensitive to phospho-eIF2α and restoring translation | Directly engages the eIF2B β/δ interface and bridges opposing βδ-containing tetramers into higher-order octamer/decamer assemblies; described as acting through the β/δ core and as a site functionally linked to eIF2Bδ/EIF2B4 (pqac-00000025, pqac-00000026, pqac-00000028, pqac-00000029) | Preclinical cancer therapy; neuroprotection/cognitive rescue; VWM model rescue (pqac-00000025, pqac-00000026) | Preclinical research tool/drug lead | No single EC50 reported in the cited 2023–2024 summaries here; reported to promote octamer/decamer assembly and enhance GEF activity in lysates; efficacy depends on presence of ISR signaling/p-eIF2α in tumors (pqac-00000025, pqac-00000026) | https://doi.org/10.1073/pnas.2207898120 ; https://doi.org/10.1089/ars.2022.0123 | (pqac-00000025, pqac-00000026, pqac-00000028, pqac-00000029) |
| 2BAct | eIF2B activator identified with ISRIB-class molecules; blocks inhibitory phospho-eIF2 binding and functionally renders eIF2B more resistant to ISR suppression | Acts on eIF2B allosterically in the same therapeutic space as ISRIB; cited as an eIF2B activator with relevance to assembly/state control, though β/δ contact details are less explicit in the cited excerpts than for ISRIB (pqac-00000026, pqac-00000029) | VWMD/neuropathy and broader ISR-modulation applications (pqac-00000026, pqac-00000029) | Preclinical | In a VWMD mouse model carrying eIF2Bε R191H/R191H, 2BAct reversed neuropathology; no EC50 given in the cited excerpts (pqac-00000026) | https://doi.org/10.1089/ars.2022.0123 | (pqac-00000026, pqac-00000029) |
| ISRAC / Compound A-(S) | Small-molecule eIF2B inhibitor class that stabilizes the inactive I-state and promotes the inhibitory eIF2B–eIF2(αP) complex, thereby activating the ISR | Binds an overlapping regulatory pocket near eIF2Bδ L179 and eIF2Bβ N162; can bridge βγδε tetramers and favor the inhibitory conformation rather than the active one (pqac-00000024) | Chemical-biology tool; proposed opportunities in cancer sensitization, antiviral strategies, and protein-misfolding diseases (pqac-00000024, pqac-00000027) | Preclinical / preprint-stage discovery | Compound B (a related symmetric derivative) showed EC50 ~10 µM; enrichment/elimination in DEL screening depended on eIF2(αP) complex formation and ISRIB competition (pqac-00000024, pqac-00000027) | https://doi.org/10.1101/2025.09.25.678332 | (pqac-00000024, pqac-00000027) |
| ISRAC / Compound B | Symmetric derivative of Compound A-(S); attenuates eIF2B GEF activity and reduces translation by stabilizing the inhibitory eIF2B–eIF2(αP) state | Direct evidence for EIF2B4 involvement: effect mapped to the ISRIB/β-δ pocket neighborhood; EIF2B4 L180F mutant cells showed reduced sensitivity and lost ISRIB-mediated reversal, demonstrating δ-subunit-dependent pharmacology (pqac-00000024) | ISR activation as an experimental therapeutic strategy; proposed use in cancer combination therapy and antiviral/proteostasis settings (pqac-00000024) | Preclinical / preprint-stage discovery | EC50 ~10 µM overall; in EIF2B4 L180F mutant cells EC50 shifted from 15 µM to 22.63 µM; ISRIB reversal of Compound B action was lost in the mutant (pqac-00000024) | https://doi.org/10.1101/2025.09.25.678332 | (pqac-00000024) |
| eIF2Bδ overexpression axis in breast cancer stem cells | Not a drug itself, but a translationally relevant target state: elevated eIF2Bδ suppresses strong ISR induction by preferential interaction with phospho-eIF2α, sustaining eIF2B activity | Directly implicates EIF2B4/eIF2Bδ in metastasis biology and identifies δ as a functional site of ISRIB action in CSCs (pqac-00000028) | Breast cancer stem cell survival, invasion, metastasis (pqac-00000028) | Preclinical target validation | No EC50 reported; biological effect includes requirement of elevated eIF2Bδ for CSC expansion and metastasis in animal models (pqac-00000028) | https://doi.org/10.1073/pnas.2207898120 | (pqac-00000028) |
| NCT07272525 | Single-patient investigational treatment for Cree leukoencephalopathy/vanishing white matter disease | Real-world implementation relevant to EIF2B-pathies/VWM; trial listing indicates translational movement toward individualized intervention, though mechanism/intervention details are not provided in the retrieved excerpt (pqac-00000000) | Cree leukoencephalopathy / VWM | Active, not recruiting; Early Phase 1; interventional | Enrollment: 1 participant (pqac-00000000) | https://clinicaltrials.gov/study/NCT07272525 | (pqac-00000000) |
| NCT07300397 | Single-patient investigational treatment for Cree leukoencephalopathy | Real-world implementation relevant to EIF2B-related white matter disease; retrieved clinical-trial summary supports existence of individualized translational efforts, but no β/δ-core mechanistic detail is available in the excerpt (pqac-00000000) | Cree leukoencephalopathy / VWM-related disease context | Active, not recruiting; interventional | Enrollment: 1 participant (pqac-00000000) | https://clinicaltrials.gov/study/NCT07300397 | (pqac-00000000) |


*Table: This table summarizes translational and real-world applications of eIF2B/ISR modulation relevant to EIF2B4, including activators, ISR-activating compounds, and individualized clinical-trial efforts in VWM-related disease. It highlights where the β/δ core or EIF2B4 specifically informs mechanism, drug response, and disease relevance.*