Further development of genetic engineering improved the chances to defeat deadly disorders due to discovery of innovative methods of treatment of various diseases, including oncological ones. In doing so, the methods have to go through clinical trials; they are not safe today. In fact, a paradox emerges: the trials are necessary, but they can’t be approved in accordance with regulatory requirements, as the risk for the subjects is higher than the benefit. For oncological patients, clinical trials, however, are the last chance for salvation. This requires an additional ethical discussion regarding approval of ethical expertise by the corresponding authorities in these exceptional cases. In this regard, the author of the article provides an ethical assessment of human genome editing applications from the point of view of risk and benefit for a subject and community of subjects, taking into account such ethical principles as ‘human priority’, ‘precautionary principle’ and ‘principle of responsibility to future generations’.