Potency-matched Dual Cytokine–Antibody Fusion Proteins for Cancer Therapy

Abstract

A novel biopharmaceutical, consisting of the F8 mAb (specific to a splice isoform of fibronectin) simultaneously fused to both TNF and IL2, was found to react with the majority of solid tumors and hematologic malignancies in mouse and man, but not with healthy adult tissues. The product selectively localized to neoplastic lesions , as evidenced by quantitative biodistribution studies using radioiodinated protein preparations. When the potency of the cytokine payloads was matched by a single-point mutation, the resulting fusion protein (IL2-F8-TNF) eradicated soft-tissue sarcomas in immunocompetent mice, which did not respond to individual antibody-cytokine fusion proteins or by standard doxorubicin treatment. Durable complete responses were also observed in mice bearing CT26, C1498, and F9 tumors. The simultaneous delivery of multiple proinflammatory payloads to the cancer site conferred protective immunity against subsequent tumor challenges. A fully human homolog of IL2-F8-TNF, which retained selectivity similar to its murine counterpart when tested on human material, may open new clinical applications for the immunotherapy of cancer. .

Targeted enhancement of the therapeutic window of L19-TNF by transient and selective inhibition of RIPK1-signaling cascade

“…Hypotension, leukopenia, thrombocytopenia, fever, headache, nausea and hepatopathy represent the most common side effects detected in Phase II studies with recombinant TNF, while most serious toxicities include respiratory failure and coagulopathies [32]. Our group has previously demonstrated that the generation of antibody-TNF fusion proteins capable to selectively accumulate to tumors after systemic administration represents a valuable strategy to improve therapeutic window and efficacy of TNF [15][16][17]. L19-TNF is an antibody-fusion protein for the targeting of the alternatively-spliced EDB domain of fibronectin [33], that shows potent antitumor activity in preclinical models of cancer [9,34,35] and is now being investigated in clinical trials [13,18,36].…”

“…While therapeutic activity can be dramatically improved by the selective delivery of cytokines to tumors via antibodies [19][20][21], toxicity profile is often similar to the one of unmodified cytokines.…”

“…The targeted delivery of TNF causes a rapid and selective hemorrhagic tumor necrosis in mouse models of cancer [19][20][21] and in patients [22]. TNF also boosts the activity of NK cells and of CD8+ T cells, which are required in order to eliminate the minimal residual disease and lead to protective immunity in mice [21,23].…”

Comparative evaluation of bolus and fractionated administration modalities for two antibody-cytokine fusions in immunocompetent tumor-bearing mice

“…In that case, a progressive decrease in the cumulative %ID/g value in the tumor mass was observed [ Figure 2D]. The targeted delivery of TNF to the tumor blood vessels may cause a rapid and selective shutdown of the vasculature, leading to hemorrhagic necrosis [25,36,37,61]. The conversion of a tumor mass into a necrotic scab within the first few hours is likely to prevent product accumulation for subsequent injections.…”

The immunocytokine L19-TNF eradicates Sarcomas in combination with Chemotherapy agents or with immune check-point inhibitors

“…TNF is a homo-trimeric pro-inflammatory cytokine, mainly produced by macrophages, NK and T cells [10,11]. TNF is involved in inflammatory processes and as indicated by its name, it may display a potent anticancer activity against some malignancies, by promoting hemorrhagic necrosis and by inducing direct apoptosis of tumor cells [12][13][14][15][16][17]. Moreover, TNF may activate the immune system as a result of the increased inflammation [18][19][20].…”