Anti-IL2 monoclonal antibody, clone MQ1-17H12 [FITC]

Background Purpose: The combination of a mammalian target of rapamycin inhibitor and lenalidomide showed enhanced preclinical cytotoxicity. We conducted a phase 1 study in advanced solid tumour patients to assess safety, efficacy and pharmacodynamic (PD) outcomes. Methods We employed a 3+3 dose escalation design to establish the safety and recommended phase 2 doses (RP2D) of daily everolimus and lenalidomide in patients with advanced solid tumours. The starting doses were 5 and 10 mg, respectively, with planned escalation to maximum single-agent doses of 10 and 25 mg in the absence of dose-limiting toxicity. PD endpoints of lymphocyte subsets and immune cytokines were assessed in peripheral blood using multiparameter flow cytometry and LUMINEX assay. Efficacy was evaluated by cross-sectional imaging after every two cycles of treatment. Results The study enrolled 44 patients, median age of 58 years and 28 males (63.6%). The RP2D was established as 10 and 25 mg daily continuously for everolimus and lenalidomide. Common (>5%) grade >= 3 adverse events included rash (19%), neutropenia (19%), hypokalaemia (11%) and fatigue (9%). Best efficacy outcomes in 36 evaluable patients were partial response in 5 (13.8%), stable disease in 24 (55.8%) and progressive disease in 7 (19.4%) patients. PD assessment revealed significant association of cytokine levels (interleukin-2 (IL2), IL21 and IL17), baseline activated and total CD8+ lymphocytes and change in B cell lymphocytes and activated NK cells with clinical benefit. Conclusions The study demonstrated the safety of everolimus and lenalidomide with promising efficacy signal in thyroid and adenoid cystic cancers.

Effector CD8(+) T cells conditioned with IL12 during activation mediate enhanced antitumor efficacy after adoptive transfer into lymphodepleted hosts; this is due in part to improved IL7 responsiveness. Therefore, we hypothesized that increasing the intensity or type of lymphodepletion would deplete more IL7-consuming host cells and improve the persistence and antitumor activity of IL12-conditioned CD8(+) T cells. Using cyclophosphamide, fludarabine, and total body irradiation (TBI, 6 Gy) either individually or in combination, we found that combined lymphodepletion best enhanced T-cell engraftment in mice. This improvement was strongly related to the extent of leukopenia, as posttransfer levels of donor T cells inversely correlated to host cell counts after lymphodepletion. Despite the improvement in engraftment seen with combination lymphodepletion, dual-agent lymphodepletion did not augment the antitumor efficacy of donor T cells compared with TBI alone. Similarly, IL7 supplementation after TBI and transfer of tumor-reactive T cells failed to improve persistence or antitumor immunity. However, IL15 or IL2 supplementation greatly augmented the persistence and antitumor efficacy of donor tumor-reactive T cells. Our results indicate that the amount of host IL7 induced after single agent lymphodepletion is sufficient to potentiate the expansion and antitumor activity of donor T cells, and that the efficacy of future regimens may be improved by providing posttransfer support with IL2 or IL15. Significance: The relationship between lymphodepletion and cytokine support plays a critical role in determining donor T-cell engraftment and antitumor efficacy. (C) 2018 AACR.