Immunostimulatory gene therapy combined with checkpoint blockade reshapes tumor microenvironment and enhances ovarian cancer immunotherapy

Immune evasion has made ovarian cancer notorious for its refractory features, making the development of immunotherapy highly appealing to ovarian cancer treatment. The immune-stimulating cytokine IL-12 exhibits excellent antitumor activities. However, IL-12 can induce IFN-γ release and subsequently upregulate PDL-1 expression on tumor cells. Therefore, the tumor-targeting folate-modified delivery system F-DPC is constructed for concurrent delivery of IL-12 encoding gene and small molecular PDL-1 inhibitor (iPDL-1) to reduce immune escape and boost anti-tumor immunity. The physicochemical characteristics, gene transfection efficiency of the F-DPC nanoparticles in ovarian cancer cells are analyzed. The immune-modulation effects of combination therapy on different immune cells are also studied. Results show that compared with non-folate-modified vector, folate-modified F-DPC can improve the targeting of ovarian cancer and enhance the transfection efficiency of pIL-12. The underlying anti-tumor mechanisms include the regulation of T cells proliferation and activation, NK activation, macrophage polarization and DC maturation. The F-DPC/pIL-12/iPDL-1 complexes have shown outstanding antitumor effects and low toxicity in peritoneal model of ovarian cancer in mice. Taken together, our work provides new insights into ovarian cancer immunotherapy. Novel F-DPC/pIL-12/iPDL-1 complexes are revealed to exert prominent anti-tumor effect by modulating tumor immune microenvironment and preventing immune escape and might be a promising treatment option for ovarian cancer treatment.

Drug-induced sarcoidosis-like reaction in adjuvant immunotherapy: Increased rate and mimicker of metastasis

BACKGROUND

Anti-[programmed cell death protein 1 (PD-1)] antibodies nivolumab and pembrolizumab were approved for adjuvant treatment of melanoma as they demonstrated improved relapse-free survival. Currently, combined anti-PD-1 plus anti-[cytotoxic T-lymphocyte-associated protein 4 (CTLA4)] blockade is being investigated in adjuvant and neoadjuvant trials. Sarcoidosis-like reactions have been described for immune checkpoint inhibitors and are most likely drug-induced. The reported rate of sarcoidosis/sarcoidosis-like reactions within clinical melanoma trials is <2%. We observed that a remarkably higher number of melanoma patients (10/45 patients, 22%) treated with immune checkpoint inhibitor (ICI) within an adjuvant clinical trial-developed drug induced sarcoidosis-like reaction (DISR) mimicking metastasis.

CASE PRESENTATION

Of 45 stage III melanoma patients who were treated at our institute with adjuvant ICI (either nivolumab alone or in combination with ipilimumab) within a two-armed, blinded clinical trial, ten developed a DISR. Three of the ten patients were men, median age was 52 years (range, 32-70 years). DISRs were asymptomatic and generally detected radiographically at first radiographic imaging after the start of therapy (median time, 2.8 months) and described as a differential diagnosis to tumour progression. In one patient, DISR was only apparent 13.1 months after start of therapy and 4 weeks after the end of ICI treatment. DISR presented as mediastinal/hilar lymphadenopathy in 8/10 patients (as only site or in addition to lung, skin and/or bone involvement), one patient had only lung and cutaneous, one patient only cutaneous DISR. Biopsies from lymph nodes, skin and bone were taken in 8/10 patients, and histology confirmed sarcoidosis-like reactions (SLRs). As patients were asymptomatic, no treatment for DISR was required, and study treatment was stopped for DISR in only one patient due to bone involvement. DISRs have resolved or are in remission in all patients. At a median follow-up time of 15.3 months (range, 12-17.6 months), two patients experienced melanoma relapse.

CONCLUSIONS

In most cases, sarcoidosis could only be differentiated from melanoma progression on biopsy. Treating physicians as well as radiologists have to be aware of the potentially higher rate of DISR in patients receiving adjuvant ICI. A thorough interdisciplinary workup is required to discriminate from true melanoma progression and to decide on continuation of adjuvant ICI treatment.