Part A - Determination of the Safety and Tolerability of Two Dose Levels and Selection of an Upamostat Dose for Part B

Part A - Determination of the Safety and Tolerability of Two Dose Levels and Selection of an Upamostat Dose for Part B

Part A - Determination of the safety and tolerability of two dose levels and selection of an upamostat dose for part B;Part B - Comparison between upamostat and placebo in time to sustained recovery from symptomatic illness.

Part A - Determination of the safety and tolerability of two dose levels and selection of an upamostat dose for part B;Part B - Comparison between upamostat and placebo in time to sustained recovery from symptomatic illness.

Part A - Determination of the safety and tolerability of two dose levels and selection of an upamostat dose for part B;Part B - Comparison between upamostat and placebo in time to sustained recovery from symptomatic illness. Sustained recovery is recovery, per below definition, maintained for at least 28 days or through end of study, whichever comes first.

Part A - Determination of the safety and tolerability of two dose levels and selection of an upamostat dose for part B;Part B - Comparison between upamostat and placebo in time to sustained recovery from symptomatic illness. Sustained recovery is recovery, per below definition, maintained for at least 28 days or through end of study, whichever comes first.

Part A - Determination of the safety and tolerability of two dose levels and selection of an upamostat dose for part B;Part B - Comparison between upamostat and placebo in time to recovery from symptomatic illness.

Part A - Determination of the safety and tolerability of two dose levels and selection of an upamostat dose for part B;Part B - Comparison between upamostat and placebo in time to recovery from symptomatic illness.