This study involves the administration of a monoclonal antibody called OpSCF subcutaneously (given as an injection under the skin like a flu shot) every 2 weeks. Participants who are determined to meet the requirements to take part in the study will have a 50% chance (like flipping a coin) of receiving the active study drug or placebo (does not have active study drug in it) for the first part of the study (for about 16 weeks).
Compensation may be provided for time and travel. Participation will come at no cost to you.