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About Early Access
Merus N.V. (“Merus” or “us,”we,” “our”) is a clinical-stage immuno-oncology company developing innovative full-length human multispecific antibody therapeutics (Biclonics® and Triclonics®). Clinical trials form the foundation of our development programs. These trials are designed to assess the safety, tolerability and efficacy of investigational medicines. Participation in a clinical trial represents the best way, in a controlled setting, to gain access to an investigational medication. In some circumstances, a patient may not be able to participate in a clinical trial. Seeking use of an investigational medication under these circumstances is permitted by certain regulatory authorities, including the U.S. Food and Drug Administration (“FDA”), and commonly referred to as compassionate use, early access, or expanded access. Our policy is intended to comply with FDA requirements for any such use or access.

Procedure for Requesting Investigational Medication for Early Access

  • Requests should be sent via e-mail to and must originate from the patient’s treating physician.
  • Requests will be acknowledged within 5 business days of receipt.

Criteria for Evaluation
Merus considers many factors when evaluating a request for early access of an investigational medicine, such as (but not limited to) the strength of the currently available data, including clinical data together with patient condition and the benefit-risk profile, the impact of providing access to an investigational medicine on its clinical development program, including the ability to complete patient enrollment and other necessary aspects of the clinical trials, the phase of development, and probability and timing of regulatory approval.

A patient may be considered for early access to an investigational medicine based upon evaluation of
the following minimum requirements (and other requirements may apply based on the circumstances):

  • There must be adequate data supporting use of the investigational medication in the treatment of the patient’s disease.
  • There are no adequate standard or investigational therapies available.
  • Sufficient safety and efficacy data must exist for use of the medicine at the time of request.
  • Sufficient information must be made available to make a benefit-risk analysis consistent with the establishment of an early access program.
  • Sufficient clinical data is available to identify an appropriate patient-specific dose.
  • A patient’s treating physician and Merus’ clinical team both believe there is the potential for the specific patient under consideration to reasonably expect benefit from the treatment.
  • Adequate supply exists to support both the ongoing clinical trials and approved early access, until and if a product becomes commercially available.
  • The patient is not eligible for or cannot participate in a Merus-sponsored study for the therapy being requested.
  • Early access will not adversely impact the clinical development program or the regulatory approval process.
  • The request must be made, unsolicited, by the patient’s treating physician. The physician must be appropriately licensed.
  • The treating physician must also agree to comply with the safety and monitoring requirements.
  • Where appropriate, demonstration of efficacy and safety may be required for continued treatment.
  • Early access is permitted or approved in the country, region, and/or state where the investigational medicine will be administered.
  • Any condition, in addition to those listed above, that in the opinion of Merus may preclude appropriate use of the investigational medicine, will be considered.

Given the unique nature of individual requests for early access to investigational medications, there is no guarantee a request will be fulfilled.

Merus may revise, suspend or terminate the early access program at any time.

All early access requires approval by the Chief Medical Officer and Merus management and decisions will be made based on scientific and other evidence available to Merus at the time of the request.

Last updated: August 15, 2023
Biclonics® and Triclonics® are registered trademarks of Merus N.V.