Multiple dose escalation study in a multicenter, randomized, single-blind, parallel-group,
placebo-controlled design to investigate safety, tolerability, pharmacokinetics, and
pharmacodynamics of BAY 1213790 administered subcutaneously in healthy male subjects.

BAY 1213790 is a new compound developed by the company Bayer AG that is
undergoing clinical development because of its characteristics for preventing
thrombosis. Venous thromboembolism is a disease that includes both deep vein
thrombosis and pulmonary embolism. It is a common, potentially fatal disorder
that affects hospitalized and non-hospitalized patients and may lead to
long-term complications. Thromboembolic disorders are a major cause of disease
and death in the entire world, causing or contributing to acute coronary
syndromes, embolic and thrombotic stroke, and peripheral arterial occlusion.

BAY 1213790 is a fully human monoclonal antibody that binds specifically to
activated factor XI, one of the enzymes (= proteins that speeds up and guides
processes in the body) responsible for the coagulation, resulting in modulation
of the coagulation process.

The purpose of this study is to investigate how safe the new compound BAY
1213790 is and how well it is tolerated when it is administered as an injection
under the skin to healthy male volunteers. BAY 1213790 has been administered to
humans before.

This study will be performed in 32 healthy male volunteers. The study will be
performed at 3 clinical sites in The Netherlands and Germany.

The study will consist of up to 2 groups of 16 volunteers each. You can
participate in one of these groups.

It will also be investigated how quickly and to what extent BAY 1213790 is
absorbed and eliminated from the body (this is called pharmacokinetics). In
addition, the effect of BAY 1213790 on indicators for blood clothing will be
investigated (this is called pharmacodynamics).

The effects of BAY 1213790 will be compared to the effects of a placebo. A
placebo is a medicine without any active ingredient. It is a *fake* medicine.

BAY 1213790 or placebo will be given as an s.c. injection.

During the first 4 hours after administration of the study compound the
volunteer will have to lie down, and they are not allowed to eat. 'They may
only drink water.

Whether the volunteer will receive BAY 1213790 or placebo will be determined by
chance. They will have a 7 in 8 chance of receiving BAY 1213790 and a 1 in 8
chance of receiving placebo. Per group, 14 volunteers will receive BAY 1213790
and 2 volunteers will receive placebo. They will not be told if BAY 1213790 or
placebo will be administered, but the responsible doctor knows; we call this a
single-blinded study.

Group 1 Day 1 ; BAY 1213790 100 mg or placebo once
Group 1 Day 29, 57, 85; BAY 1213790 35 mg or placebo once per dosing day
Group 2 Day 1; BAY 1213790 200 mg or placebo once
Group 2 Day 29, 57, 85; BAY 1213790 70 mg or placebo once per dosing day

Group 1 Day 1 ; BAY 1213790 100 mg or placebo once
Group 1 Day 29, 57, 85; BAY 1213790 35 mg or placebo once per dosing day
Group 2 Day 1; BAY 1213790 200 mg or placebo once
Group 2 Day 29, 57, 85; BAY 1213790 70 mg or placebo once per dosing day

Pain, minor bleeding, bruising, possibly an infection.