Figure 7. Enhanced IL-2–dependent engraftment and antitumor activity by SOCS1-edited TIL following transfer into a solid-tumor model.

(A) TILs or KSQ-001 was adoptively transferred into NOG or hIL-2–Tg NOG mice, with engraftment evaluated over time by quantifying the frequency of human CD45⁺ cells present within the peripheral blood. Top row: left, frequency of human CD45⁺ cells by mouse strain and treatment group on day 21; right, frequency of KSQ-001 in hIL-2–Tg NOG mice over time. Bottom row: frequency of CD4⁺ and CD8⁺ T cells from TILs or KSQ-001 on day 21 in hIL-2–Tg mice. (B) TILs or KSQ-001 was adoptively transferred into NOG with 45,000 U of human IL-2 administered i.p. daily, with engraftment evaluated at day 14. (C) TILs or KSQ-001 was adoptively transferred into hIL-15–Tg NOG mice with 45,000 U of human IL-2 administered i.p. daily for 3 days, with engraftment evaluated at day 14 and NSG mice used as a comparator (D) Schematic of the mOKT3-A375/TIL model. A375 melanoma cells were engineered to express either high- or low-affinity membrane–associated OKT3 scFv binding domains that bind and agonize CD3 expressed by TILs. TILs generate an antitumor cytolytic response through production of IFN-γ and release of cytolytic granules. (E) TILs were cocultured with low-affinity A375-mOKT3 spheroids at various effector to target (E:T) ratios, with tumor killing assessed by Incucyte assay over time. EC₅₀ kill curve at 72 hours from a representative donor is shown. (F) EC₅₀ values from 17 donors and 22 independent paired TIL and KSQ-001 samples are shown, with each dot representing an individual paired donor. Statistical analysis was done using 2-tailed, paired t test. (G) hIL-2–Tg NOG mice bearing high-affinity A375-mOKT3 tumors approximately 100 mm³ in size were treated with donor-paired sgOlf-edited melanoma TILs or unengineered NSCLC TILs versus donor-paired KSQ-001, with tumor growth assessed over indicated time points. An unpaired, 2-tailed Student’s t test was used to evaluate statistical significance between sgOlf TIL or TIL versus KSQ-001 treatment groups in A–C and G, and 2-way ANOVA was used in G. **P < 0.01; ***P < 0.001; ****P < 0.0001.