Coronavirus disease 2019 (COVID-19), which started in China in December of 2019, has led to a pandemic extremely quickly, with effects on health in many countries.

When the immune response is unable to control infection, the virus activates macrophages and granulocytes, causing the progressive release of proinflammatory cytokines, especially IL6, IL1, IL10, interferon and TNF, provoking a real “cytokine storm”.1–5 In some patients, it induces the appearance of pulmonary infiltrates and rapid development of respiratory failure and severe acute respiratory syndrome (SARS), which is the main cause of mortality in these patients.6–8 Although mortality vary between countries, it has been estimated 0–3% to 1% in general population infected and 14% among hospitalized cases (95% CI 3.9–32%).9–12

Management, especially in patients with severe disease, is one of the main problems posed by this disease. So far, it has been based on observational studies or on drugs used in other viral diseases. Although there are numerous clinical trials underway, there is no evidence to recommend a specific treatment.

In the first phase of the disease, treatment with antiviral drugs (remdesivir,13 a combination of lopanivir/ritonavir,14 or interferon β1b15), or drugs that may interfere with the development of the virus (hydroxychloroquine),16 predominates. After a few days, in the second inflammatory phase, associated with the release of cytokines, the use of drugs such as tocilizumab (TCZ), with anti-IL6 action and therefore for the treatment of SARS, predominates.5,8,17

Given its high contagiousness, this virus has caused an explosion of cases, with saturation of the health system and of intensive care units (ICU). In Spain, 43% of infected patients required hospital admission and 3.9% ICU admission. Approximately 75% of patients admitted for COVID19 present positive imaging for interstitial pneumonia (IP).10,18,19

As in many other hospitals in Spain, with a large number of patients admitted for COVID19-IP, our center had to restructure most of the hospitalization areas and the activities of the entire medical staff at the times of greatest impact of the pandemic. In this context, and with the possibility of supply problems of drugs such as TCZ, in cases of SARS, possible therapeutic alternatives were sought, for their early administration or as a bridge to reduce the consumption of TCZ.

Baricitinib (BARI) is a selective JAK1/JAK2 intracellular route inhibitor drug, administered orally at a daily dose of 2–4mg, and approved for the treatment of adult patients with rheumatoid arthritis.20 Unlike other biological drugs, which are predominantly inhibitors of one cytokine, BARI inhibits multiple cytokines, such as IL-6 and interferon, among others.21–22 In addition to its anti-inflammatory effect, there are data indicating that BARI, at the doses used in rheumatology, may have antiviral action, interfering with its binding to ACE2 receptors (angiotensin-converting enzyme).23–24 This inhibits the entry of the virus into the cell and its intracellular coupling by binding to GAK (cyclin G-associated kinase), which regulates endocytosis and acts on AAK1 (Associated protein kinase 1), thus interfering with viral replication.24–25

The main objective of the study is to describe the experience of treatment with BARI and/or TCZ, in monotherapy or combined, in patients admitted for IP secondary to COVID19, and for 30 days after discharge.

This is a retrospective observational study. The medical records of the patients admitted to our center due to IP secondary to COVID19, demonstrated by PCR (polymerase chain reaction) technique, who started treatment with BARI and/or TCZ, from March 27 to April 2, 2020 and their clinical progress until discharge, was reviewed. Survival and serious complications were reviewed after 30 days of discharge.

COVID19 infection causes mild illness in most patients. However, approximately 20% of patients can progress to SARS due to the appearance of IP, sepsis, or septic shock, requiring admission to an ICU in about 5% of cases.27 Since many people become infected within a short period of time, it can lead to a health care collapse.

The current treatment of patients with IP by COVID19 is a challenge for clinicians. Pharmacological treatment is not based on the results of clinical trials, but on previous experiences with other viral infections. There are studies that demonstrate a direct relationship between IL6 level and patient severity.28 Hence the interest in using drugs with anti-IL6 activity, such as TCZ, in these patients.

In general, TCZ was used after the first published efficacy data in China, due to its anti-IL6 action in the “cytokine storm”, in patients with IP and SARS.17 Given the possibility of difficulties in its supply in that time, the possible benefit of another drug with anti-IL6 action, such as BARI, administered orally, was assessed at our center at an early stage of respiratory failure due to COVID19.

Initially, BARI was introduced in our center for patients waiting to start TCZ, at a dose of 2mg daily, due to the age of the patients and the presence of high levels of D-dimer. Subsequently, since all patients received prophylactic doses of low molecular weight heparin, it was changed to 4mg daily, without finding relevant differences between both doses.

As expected, in our study patients receiving BARI and/or TCZ, presented more serious data upon admission, especially PaO2/FiO2. However, in the group who received BARI monotherapy, with the worst PaO2/FiO2 at admission, none of the patients was admitted to the ICU, as occurred in the group that was not treated with BARI and/or TCZ. Therefore, 3 patients, with PaO2/FiO2<200), received BARI before adding TCZ and continued to receive BARI at the same dose (sequential treatment), not requiring admission to the ICU. Regarding mortality, no differences were detected between all groups. On the other hand, patients who received TCZ, had the worst clinical evolution and therefore there was a higher percentage who entered the ICU, but with similar mortality. In addition, patients with poor clinical evolution or those did not respond to BARI, received TCZ, and presented a higher percentage of admission to ICU than the other groups.

These results could reinforce the idea of introducing BARI early, at the beginning of respiratory failure, measured with PaO2/FiO2, and TCZ could be add, if there is no clinical response and PaO2/FiO2 worsening, to prevent the need for ICU admission. On the other hand, a sequential treatment (BARI-TCZ-BARI) could be considered.

The length of time that the patient receives BARI and its early introduction, may be related to the possible efficacy of the drug. In patients of our study receiving BARI monotherapy, the mean treatment is 6 days compared to 2.8 days for the group receiving BARI and TCZ combined, mainly because in many patients BARI was started waiting for TCZ.

During the study, no relevant side effects related with BARI or TCZ have been recorded, even 30 days after discharge, such as thrombotic symptoms, herpes zoster, leukopenia, thrombopenia, or significant alteration of blood transaminases. This can be related to the short period of treatment received.

The age of the patients can be relevant for the prognosis. In our study, numerically relevant differences were detected between those over and under 70 years of age. In patients over 70, 3% of them were admitted to the ICU, but the mortality rate reached 31%. The mortality rate varies between series. In our study 15 (25%) patients died, all in the first 30 days after admission, but the 73% in the first 15 days. However, in the study of Chen,12 14% of 799 patients admitted died. In the registry from Spanish Society of Internal Medicine (SEMI), with 6.424 patients included, 8.5% received TCZ and 8% required ICU. The mortality rate was 21%, reaching 73% in patients over 70.29

So far, two studies from Italy have been published in patients treated with BARI for pneumonia due to COVID19. The first study, in 12 patients, although the patients were not randomized, they were compared with previous patients who did not receive BARI,30 with promising results. Patients received standard treatment and BARI daily for 2 weeks and their clinical parameters, CRP, and respiratory evaluation improved in the first and second week. No severe side effects were detected and none of the patients required ICU admission. Recently, the same group has published a multicenter study with 113 patients to which BARI was added to the standard treatment and compared with 87 patients who received standard treatment. At 2 weeks of treatment, the BARI group had significantly lower mortality and ICU admission.31

Our study has obvious limitations: it is a retrospective and observational study, with a small number of patients and a great heterogeneity among patients treated with BARI or TCZ. It presents a confusion bias due to the severity of the disease, because the most severe patients, and therefore with greater probability of admission to the ICU and mortality, received treatment with anti-IL6 drugs. However, this study aims to draw attention to the possible benefit of BARI in severe cases of IP in this disease.

In summary, the treatment for patients with IP due to COVID19 has not been fully established. However, the combination of cytokine storm and IP, especially in those older than 70 years, darkens the prognosis. We have showed our experience with BARI and TCZ in this clinical situation. Treatment with BARI and TCZ did not cause serious side effects. They could be considered early in patients with NI secondary to COVID19 and impaired PaO2/PaFi. Randomized clinical studies with these drugs, including sequential therapy are required.

This article does not contain any studies with animals performed by any of the authors. All procedures performed in this study involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.

The design of the study was approved by the AEMPS (Spanish Agency of Medicines and Medical Products) and by the Research Ethics Committee of University Hospital of Elche, Spain.

All authors contributed to the study conception, data collection and design. analysis were performed by José Rosas. The first draft of the manuscript was written by José Rosas and all authors commented on previous versions of the manuscript. All authors read and approved the final manuscript.

As it is a retrospective study, it is not necessary to obtain informed consent.

The study was supported by a research grant from the Association for Research in Rheumatology of the Marina Baixa (AIRE-MB).

The authors have no conflict of interest.