Clinical Trials

What Are Clinical Trials?

Clinical trials are research studies conducted to determine the safety and efficacy of an investigational medicine for the intendent patient population. Collectively, the results from the various phases of a clinical trial are submitted to regulatory agencies, such as the U.S. Food and Drug Administration and the European Medicines Agency, to gain approval of the new drug or treatment.

Clinical Trial Phases

The clinical research process typically follows a series of phases that gradually test the safety and effectiveness of a new potential drug in people, starting from smaller scale Phase 1 trials to larger scale Phase 3 trials.

  • Phase 1

    A Phase 1 trial focuses on evaluating the safety and tolerability of an investigational drug in a small number of individuals that are, often, healthy volunteers.

  • Phase 2

    A Phase 2 trial evaluates the safety and efficacy of the investigational drug in patients with the disease or condition being studied, as well as optimal dosages and dosing schedule.

  • Phase 3

    A Phase 3 trial continues to evaluate the safety, efficacy and dosage of the investigational drug, often times compared to a placebo or another drug that is used to treat the same condition. Phase 3 trials generally involve a large number of patients. An investigational drug that completes Phase 3 can be submitted to regulatory agencies for approval to be marketed to the general public.

  • Phase 4

    In some cases, a regulatory agency may require, or companies may voluntarily pursue, a Phase 4 trial after a drug is approved to gain more information about that drug. These Phase 4 trials are used to gain additional experience from the treatment of patients in the intended therapeutic indication and are commonly intended to generate additional safety data regarding use of the drug in a clinical setting. general public.

Currently Recruiting Clinical Trials

We are committed to developing a pipeline of potentially disease-modifying product candidates for patients who are suffering from hematological, pulmonary and cardiovascular disorders with high unmet medical need. Our currently recruiting clinical trials are listed below. If you’re interested in joining a Keros clinical trial, please discuss your potential eligibility with a clinical study physician.

Product CandidateDiseasePhase 
KER-050MyelofibrosisPhase 2
KER-050Myelodysplastic SyndromesPhase 2
KER-012Pulmonary Arterial HypertensionPhase 2

Patient Resources

Myelodysplastic Syndromes (MDS)


Pulmonary Arterial Hypertension (PAH)

Expanded Access Policy

Keros Therapeutics, Inc. (Keros) is a clinical-stage biopharmaceutical company focused on the discovery, development and commercialization of novel treatments for patients suffering from hematological, pulmonary and musculoskeletal disorders with high unmet medical need. As we advance our product candidates through clinical development, our goal is to ensure access to these product candidates at the appropriate time and in the correct manner for patients. Use the links provided for more information about Keros’ product candidates and pipeline. In addition, you can find additional information about Keros’ ongoing clinical trials by accessing

Expanded access, also sometimes referred to as “compassionate use,” refers to a potential pathway for a patient with a serious or immediately life-threatening disease or condition may gain access to an investigational therapy outside of a clinical trial when there is no comparable or satisfactory therapy available. Several factors consistent with guidelines by the U.S. Food and Drug Administration (FDA) and other regulatory agencies should be taken into account when considering expanded access, including, but not limited to:

  • The illness must be serious or immediately life-threatening, with no other satisfactory treatment options (such as approved products or enrolling clinical trials).
  • There is sufficient evidence that the potential benefit to the patient would likely outweigh the potential risks, based on all available safety and efficacy information.
  • Ability to provide a product in a fair and equitable manner, so that there is adequate manufacturing capacity for ongoing programs.
  • Providing the investigational drug will not interfere with clinical trials that could support the investigational drug’s development or marketing approval for the treatment indication.

At this time, Keros does not have an investigational product candidate available for expanded access. We believe that participation in clinical trials, which are carefully designed to determine the safety and efficacy of an investigational therapy, is the most appropriate way for patients to access an investigational therapy until sufficient evidence is available that suggests the potential benefit outweighs the risk.

As authorized by the 21st Century Cures Act, Keros may revise this Expanded Access Policy at any time.

If you have additional questions, please speak with your treating physician or contact Keros at . We anticipate acknowledging receipt of requests sent to this email within five business days.