The purpose of this study is to assess the efficacy (decrease in profound fatigue), safety and pharmacokinetics of RSLV-132 in subjects with long Corona Virus (COVID) syndome

This is a double-blind placebo-controlled study in approximately 70 subjects with long COVID syndrome. After being informed about the study and potential risks, all subjects giving written informed consent will be screened to determine eligibility in the 21 days before the start of study treatment. Prior to the first study treatment administration, subjects will be randomized in a 2:1 ratio to receive six administrations of 10 mg/kg RSLV-132 or placebo on Days 1, 8, 15, 29, 43 and 57. Subjects will then attend an end of study visit approximately 10 weeks after the start of treatment (Day 71).

Inclusion Criteria:

• Laboratory-confirmed novel coronavirus (SARS-CoV-2) infection as determined by qualitative Polymerase Chain Reaction (PCR) at least 24 weeks prior to Baseline
• PROMIS Fatigue SF 7a raw score of 21 or greater at Screening (confirm onset of fatigue was post-infection)
• Able to communicate and able to provide valid, written informed consent
• Ages 18 to 75 inclusive
• Minimum weight of 45 kg
• Female participants shall be either of non-child-bearing potential (permanently sterilized by bilateral tubal occlusion, hysterectomy, or bilateral salpingectomy), or menopausal (more than one year since last menstrual cycle and confirmed by blood FSH levels > 22 mIU/mL) OR practicing highly effective contraception (e.g., oral (but not including progestogen-only oral contraceptives), injectable, implantable or transdermal contraceptives, a non-hormonal intrauterine device [IUD] or an intrauterine hormone releasing system [IUS]) for at least 2 months prior to dosing and until 125 days after the last dose. In terms of sexual relations, female participants not practicing highly effective contraception as described above should abstain or only engage with male partners who are sterile or vasectomized. Female participants of child-bearing potential will also be required to have a negative serum pregnancy test [beta human chorionic gonadotropin [ß-hCG]) at Screening and negative pregnancy urine test at Baseline. Female participants must agree not to donate eggs from the first dose until 125 days after the last dose
• Male participants, who are not sterile or vasectomized, must agree to abstain or only engage with female partners who use highly effective contraception from the first dose until 125 days after the last dose. Male participants must also agree not to donate sperm from the first dose until 125 days after the last dose

Exclusion Criteria:

• Previous admission to the intensive care unit for COVID-19-related symptoms
• Presence of orthostatic hypotension or tachycardia at Screening
• Completion of COVID-19 vaccination less than 4 weeks of Baseline (i.e., 4 weeks after the second dose of a two-dose vaccine or 4 weeks after a single dose vaccine)
• Use of therapies to treat COVID-19 symptoms such as remdesivir, dexamethasone (or any other corticosteroid), or convalescent plasma within 14 days of Baseline
• Use of concomitant medications that are sedating
• Screening lab abnormalities that may cause fatigue such as severe anemia or hypocalcaemia
• History of anaphylaxis to a medication, diet, or environmental exposure such as bee sting
• Previous diagnosis of chronic fatigue syndrome, fibromyalgia, lupus, Sjogren's syndrome, or postural orthostatic tachycardia syndrome (POTS)
• Previous diagnosis of sleep apnea
• Participation in another clinical study with receipt of an investigational product within 3 months or 5 half- lives, of last administration (whichever is longer) from Baseline
• The presence of a clinically significant infection in the judgement of the Investigator, within seven days of Baseline
• Positive test for hepatitis B, C, or HIV at Screening
• Positive pregnancy test at Screening or Baseline
• Female subjects currently pregnant or breast feeding at Baseline
• Inability or unwillingness to comply with protocol-specified procedures which, in the opinion of the Investigator, would make the subject unsuitable for study participation](streamdown:incomplete-link)