Inclusion Criteria:  Patients who have signed a written consent to participate in the study Hospitalized patients with a diagnosis: COVID-19 coronavirus disease confirmed by laboratory testing regardless of the severity of clinical signs no later than 72 hours before screening (U07.1 - virus was identified), or COVID-19 coronavirus disease, when the infection is diagnosed clinically or epidemiologically no later than 72 hours before screening, but laboratory tests are inconclusive or unavailable (U07.2 - virus was not identified), moderate form. To be classified as a moderate form, the patient must have at least one of the following criteria: Body temperature > 38 °C; respiratory rate (RR) > 22/min; shortness of breath during physical exertion; CT (radiography) findings typical of viral lesion (minimal or average lesion volume, Grade 1-2 on CT); SpO2<95 %; serum C reactive protein (CRP) > 10 mg/L Males and non-pregnant females (negative pregnancy test or human chorionic gonadotropin (HCG) blood test (for females with childbearing potential)) at the age of 18 to 85 years Patients who are able to comply with all the requirements of the study protocol; Patients who agreed to use adequate methods of contraception during the entire study and for at least 7 days after the end of the study  Exclusion Criteria:  Patients treated with anticoagulants or fibrinolytics before inclusion in the study (for example, treatment of venous thromboembolism, atrial fibrillation, the presence of a mechanical prosthetic heart valve, etc.) The need to prescribe anticoagulants to the patient at therapeutic doses Active bleeding currently or within 6 months prior to screening, high risk of bleeding Severe anemia Severe thrombocytopenia Congenital thrombophilia (deficiency of antithrombin III, protein C, protein S, Leiden mutation of coagulation factor V, increased level of coagulation factor VIII, mutation of prothrombin G20210A, etc.) Other coagulation disorders and indications when anticoagulants is impossible to use according to the Investigator It is necessary to monitor and to treat in the ICU Disease with the life expectancy of <3 months Surgery on the brain or spinal cord, spine, ophthalmic or major surgery or injury in the last 90 days Gastrointestinal tract disorders that can disrupt the absorption of the study drug (Crohn's disease, ulcerative colitis, irritable bowel syndrome, etc.) Acute gastric or duodenal ulcer, erosive gastritis with increased risk of bleeding Active liver disease (viral hepatitis B or C, cirrhosis of the liver) and biliary tract disease, with the exception of non-alcoholic steatohepatitis with normal levels of hepatic transaminases Nephrotic syndrome, significant kidney diseases with the nephrotic syndrome events Severe renal failure (creatinine clearance < 30 mL/min) Active cancer (excluding non-melanoma skin cancer), defined as cancer without remission or requiring active chemotherapy or additional treatments such as immunotherapy or radiation therapy History of HIV, lues History of tuberculosis Significant drug or alcohol abuse according to the Investigator in the history or currently The development of trophic disorders on the lower extremities that do not respond to medical treatment The blood level of platelets is below 25•109L Body mass index (BMI) less than 18.5 or more than 40 kg/m2. Body weight below 40 kg or above 130 kg Systolic blood pressure (SBP) > 180 mmHg and/or diastolic blood pressure (DBP) >110 mmHg and/or SBP < 90 mmHg and/or DBP <60 mmHg Hypersensitivity or contraindications to DD217 or enoxaparin sodium Women who are pregnant or breastfeeding Women planning pregnancy during a clinical trial (including women who received a positive pregnancy test result at screening or before taking the study drug); Women of childbearing potential (including non-sterilized surgically and in the postmenopausal period less than 2 years) who do not want or cannot use adequate methods of contraception throughout the study. Adequate methods of contraception include the use of a condom or diaphragm (barrier method) with spermicide Participation in another clinical trial currently or within 30 days prior to screening, use of any study drug for 30 days or 5 half-lives (which is longer) prior to screening Inability to read or write; unwillingness to understand and follow the procedures of Study Protocol Failure to comply with the regimen of treatment or procedures, which, in the opinion of the Investigator, may affect the study results or the safety of the patient and prevent the patient from further participating in the study Any other concomitant medical or serious mental conditions that make the patient ineligible for a clinical trial, limit the validity of the informed consent, or may affect the patient's ability to participate in the study