Celyvir is an advanced therapy medicine, consisting of mesenchymal stem cells (MSCs) containing the oncolytic virus ICOVIR 5. This paper sets out a dynamic system which attempts to capture the fundamental relationships between cancer, the immune system and adenoviruses. Two forms of treatment were studied: continuous and periodic, the second being closer to the real situation. In the analysis of the first model, in addition to identifying the critical points, their properties and bifurcation points, a number of numerical simulations were carried out. It has thus been shown that there are bistability regimes in which Celyvir can produce an equilibrium of tumor progression, or even freedom from tumor. A sensitivity analysis was also performed to determine which parameters are most important in the system. Subsequently, an optimal control problem with nonlinear objective functional has been formulated, where the therapeutic goal is not only to minimize the size of the tumor cell population and the total cost of treatment, but also to prevent the tumor from reaching a critical size. It has been shown that the optimal control is bang–bang. With the second model, a threshold value of viral load has been identified at which the success of the treatment could be ensured. It is clear in both models that a low viral load would lead to relapse of the disease. Finally, it is shown that a periodic bang–bang regime should be used to optimize treatment with Celyvir.

Celyvir 是一种先进的治疗药物，由含有溶瘤病毒 ICOVIR 5 的间充质干细胞 (MSC) 组成。本文提出了一个动态系统，试图捕捉癌症、免疫系统和腺病毒之间的基本关系。研究了两种治疗形式：连续的和周期性的，第二种更接近真实情况。在第一个模型的分析中，除了确定临界点、其性质和分叉点外，还进行了多次数值模拟。因此，已经表明存在双稳态状态，其中Celyvir可以产生肿瘤进展的平衡，甚至不受肿瘤的影响。还进行了敏感性分析，以确定系统中哪些参数最重要。随后，提出了具有非线性目标函数的最优控制问题，其中治疗目标不仅是最小化肿瘤细胞群的大小和治疗总成本，而且是防止肿瘤达到临界大小。事实证明，最优控制是bang-bang。通过第二个模型，确定了可以确保治疗成功的病毒载量阈值。两种模型都清楚地表明，低病毒载量会导致疾病复发。最后，研究表明应采用周期性的 bang-bang 方案来优化 Celyvir 治疗。