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Immunotherapy is a promising antitumor strategy that can successfully be combined with current anticancer treatment. In this study, arsenic trioxide (As2O3) was shown to increase the antitumor immune response in CT26 colon tumor-bearing mice through the modulation of regulatory T cell (Treg) numbers. As2O3 induced Treg-selective depletion in vitro. In vivo, tumor-bearing mice injected with 1 mg/kg As2O3 showed a significant decrease in the Treg/CD4 cell ratio and in absolute Treg count versus controls. As2O3 exerted antitumor effects only in immunocompetent mice and enhanced adoptive immunotherapy effects. Inhibition of As2O3-induced Treg depletion by the NO synthase inhibitor NG-nitro-l-arginine methyl ester and the superoxide dismutase mimic manganese [III] tetrakis-(5, 10, 15, 20)-benzoic acid porphyrin suggested that it was mediated by oxidative and nitrosative stress. The differential effect of As2O3 on Treg versus other CD4 cells may be related to differences in the cells’ redox status, as indicated by significant differences in 2′7′dichlorodihydrofluorescein diacetate and 4,5-diaminofluorescein diacetate fluorescence levels. In conclusion, these results show for the first time, to our knowledge, that low doses As2O3 can delay solid tumor growth by depleting Tregs through oxidative and nitrosative bursts, and suggest that As2O3 could be used to enhance the antitumor activity of adoptive immunotherapy strategies in human cancer.

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Antiprogrammed death-1 (anti-PD1) and antiprogrammed death ligand-1 (anti-PD-L1) antibodies are effective checkpoint inhibitors that stimulate the immune system against many types of cancers. The flip side of these immunotherapies is the generation of immune-related adverse events, which can theoretically affect all organs. Among these side effects, lipase increase is frequently observed; however the meaning of this biological abnormality remains poorly understood. We investigate in this case study all the lipase increases greater or equal to grade 2 that occurred in patients receiving anti-PD-1 or anti-PD-L1 treatments, to determine their biological and clinical significance. Twenty-one patients were retained with lipase increase related to the immune checkpoint inhibitor. Most of them (71%) were treated for a metastatic melanoma. The peak of lipase increase was observed at a median of 2.8 (range, 0.4-11.4) months after the initiation of the anti-PD1 or anti-PD-L1 treatment, which correlates with cycle 5 of treatment. Three of 21 patients (14%) had a clinical or radiologic immune-related pancreatitis that led to a permanent discontinuation of the treatment. In 15 of 21 (71%) patients, the lipase increase was not considered as clinically significant, and the treatment was continued without complications. The 3 remaining patients discontinued the treatment for progressive disease. These data indicate that lipase increase related to anti-PD1 or anti-PD-L1 is not associated with a significant clinical event in most cases. On the basis of these data, we propose that lipase increase in an asymptomatic patient and without radiographic abnormalities of the pancreas can be reasonably regarded as a not clinically significant event, allowing the continuation of the anti-PD-1 or anti-PD-L1 treatment.

Nanoparticle technology in cancer chemotherapy is a promising approach to enhance active ingredient pharmacology and pharmacodynamics. Indeed, drug nanoparticles display various assets such as extended blood lifespan, high drug loading and reduced cytotoxicity leading to better drug compliance. In this context, organic nanocrystal suspensions for pharmaceutical use have been developed in the past ten years. Nanocrystals offer new possibilities by combining the nanoformulation features with the properties of solid dispersed therapeutic ingredients including (i) high loading of the active ingredient, (ii) its bioavailability improvement, and (iii) reduced drug systemic cytotoxicity. However, surprisingly, no antitumoral drug has been marketed as a nanocrystal suspension until now. Etoposide, which is largely used as an anti-cancerous agent against testicular, ovarian, small cell lung, colon and breast cancer in its liquid dosage form, has been selected to develop injectable nanocrystal suspensions designed to be transferred to the clinic. The aim of the present work is to provide optimized formulations for nanostructured etoposide solutions and validate by means of in vitro and in vivo evaluations the efficiency of this multiphase system. Indeed, the etoposide formulated as a nanosuspension by a bottom-up approach showed higher blood life span, reduced tumor growth and higher tolerance in a murine carcinoma cancer model. The results obtained are promising for future clinical evaluation of these etoposide nanosuspensions.

Nirmatrelvir is an antiviral drug approved for the treatment of COVID-19. The available dosage form consists of tablets marketed under the brand name PAXLOVID®. Although knowledge of nirmatrelvir’s intrinsic stability may be useful for any potential development of other pharmaceutical forms, no data regarding this matter is available to date. Preliminary forced degradation studies have shown that the molecule is stable under oxidative and photolytic conditions, while hydrolytic conditions, both acidic and basic, have proven deleterious. Indeed, the molecule presents a priori several functions that can undergo hydrolysis, i.e., three amide moieties and a nitrile function. However, considering the degradation products formed under forced conditions and which were detected and identified by LC-UV-HRMSn, the hydrolysis process leading to their formation is selective since it involved only 2 of the 4 hydrolysable functions of the molecule. Ab initio studies based on density functional theory (DFT) have helped better understand these reactivity differences in aqueous media. Some hydrolyzable functions of nirmatrelvir differ from others in terms of electrostatic potential and Fukui functions, and this seems to correlate with the forced degradation outcomes.

A disintegrin and metalloproteinase 9 (ADAM9) possesses potent metastasis-inducing capacities and is highly expressed in several cancer cells. Previous work has shown that ADAM9 participates in the adhesive-invasive phenotype in lung cancer cells in vitro. In this study, we evaluated whether ADAM9 expression plays a critical role in metastatic processes in vivo and in angiogenesis. We first found that high ADAM9 expression was correlated with poor lung adenocarcinoma patient prognosis on Prognoscan data base. In vivo model based on intravenous injection in nude mice showed that a stable downregulation of ADAM9 in A549 (TrA549 A9-) cells was associated with a lower number of nodules in the lung, suggesting lower potentials for extravasation and metastasis. On a subcutaneous xenograft we showed that TrA549 A9- produced significantly smaller tumours and exhibited fewer neovessels. In addition, in vitro human umbilical vein endothelial cells exposed to supernatant from TrA549 A9- could reduce the formation of more vessel-like structures. To further understand the mechanism, a human antibody array analysis confirmed that five cytokines were downregulated in TrA549 A9- cells. Interleukin 8 was the most significantly downregulated, and its interaction with CXCR2 was implicated in angiogenesis on an in vitro model. These results emphasize the critical influence of ADAM9 on lung cancer progression and aggressiveness. ADAM9 should at least be a marker of cancer aggressiveness and a potential therapeutic target for cancer treatment.