This is a phase I/II clinical trial using adoptive cell therapy with NK cells or memory T cells in patients affected by COVID-19.

Severe cases with COVID-19 present a dysregulated immune system with T cell lymphopenia, specially NK cells and memory T cells, and a hyper-inflammatory state.

This clinical trial proposes the use of cell therapy for the treatment of patients with worse prognosis due to SARS-CoV-2 infection (those with pneumonia and/or lymphopenia). This is an innovative and a non-pharmacological intervention.

In this phase I/II trial natural killer (NK) cells or memory T lymphocytes will be infused from donors who have recovered from COVID-19 and have complete resolution of symptoms for at least 14 days.

There will be two arms based on the biology of the donor and the patient:

Arm 1. Infusion of memory T cells from HLA partially match donors which have the SARS-COV-2 memory T cell repertoire.

Arm 2. Infusion of NK cells which are cells of the innate immune system that can eliminate virally infected cells.

The investigators expect a quick recovery of the patients with pneumonia or lymphopenia for two reasons:

1. The pool of memory T cells will increase in patients. Memory T cell levels are low in these patients. These lymphocytes have long-life memory, which upon reencountering SARS-CoV-2 will induce enhanced effector function resulting in greater protection of the patient.
2. NK cells act quickly after a viral infection. The number and function of NK cells correlates with the severity of another coronavirus infection, Severe Acute Respiratory Syndrome (SARS), originated in China in 2002.

Moreover, the investigators have previous successful experience with other viruses such as CMV, EBV and HHV-6.

Patients who have recovered from COVID-19 are the ideal donor candidates because they have immune cells with memory against SARS-CoV-2. Therefore, the infusion of NK and memory T cells from these donors will increase the pool of cells with cytotoxicity to virally infected cells, and will increase the pool of memory cells that respond quicker to a previously encountered stimulus.

This will impact in saving thousands of lives, releasing hospital beds, reducing the costs of a national health system and improving the economy of a locked-down country.

Cell therapies are safe and cost-effective and successfully used in other diseases. The investigators need new innovative treatments where others have failed.

We have performed the phase I:

Arm 1.Phase I single-center dose-escalation in 9 patients infused with memory T cells from a HLA partially match convalescent donor.

Arm 2. Phase I single-center dose-escalation in 6 patients infused with NK cells from convalescent donors.

We evaluate the safety, and feasibility, and obtained the RP2D of a single infusion.

We have performed the phase II with memory T cells:

The phase II for the infusion of memory T cells from HLA partially match convalescent donors has been carried out. 84 patients have been enrolled and randomized into the SoC treatment or the SoC plus the infusion of memory T cells.

Inclusion Criteria:

• Male or female patients ≤ 80 years of age.
• Patient with diagnosis of COVID-19 infection with laboratory confirmation by reverse-transcription PCR (RT-PCR) of SARS-CoV-2 <72 hours prior to study entry.
• Onset of symptoms < 10 days prior to administration of study treatment.
• No more than 72 hours (3 days) of hospitalization before study treatment administration.
• Phase I criteria: Patients requiring hospitalization for COVID-19, with pneumonia diagnosed with chest radiograph or computed tomography imaging or lymphopenia (absolute lymphocyte counts below 1.2 x 109cells /L) AND O2Sat ≤ 94% on room air at screening, no oxygen requirement or with an oxygen need of ≤ 2.5 lpm in nasal cannula.
• Phase II criteria: Patients requiring hospitalization with pneumonia diagnosed with chest radiograph or computed tomography imaging or lymphopenia (absolute lymphocyte counts below 1.2 x 109cells /L) AND O2Sat ≤ 94% on room air at screening, requiring or not oxygen supplementation (nasal cannula, oxygen mask with reservoir, non-invasive ventilation, etc), but excluding mechanical ventilation.
• Have a negative pregnancy test documented prior to enrollment (for females of childbearing potential).
• Be willing and able to comply with study procedures.
• Patients with the ability to comprehend and sign the informed consent
• Written informed consent obtained prior to any screening procedures.

Exclusion Criteria:

• Enrolled in another Clinical Trial for COVID19.
• Rapidly progressive disease with anticipated life-expectancy <72 hours.
• Patients requiring mechanical ventilation.
• Patients with multiorgan failure.
• Mild-moderate (grade ≥ 3) organ impairment (liver, kidney, respiratory), according to criteria from the National Cancer Institute (NCI CTCAE version 5.0).
• Severe and/or uncontrolled concurrent medical disease that in the opinion of the investigator could cause unacceptable safety risks or compromise compliance with the protocol.
• Have a known history of human immunodeficiency virus infection, Hepatitis B or Hepatitis C; testing is not required in the absence of prior documentation or known history.
• Pregnant or nursing (lactating) women, where pregnancy is defined as the state of a female after conception and until the termination of gestation, confirmed by a positive hCG laboratory test.
• Any other condition that, in the opinion if the Investigator, may interfere with the efficacy and/or safety evaluation of the trial.