Clinical Trials

milademetan FOR PATIENTS

What is Milademetan?

Milademetan (RAIN-32), is a small molecule, oral inhibitor of mouse double minute 2 (MDM2) being developed in patients with wildtype tumor protein 53 (p53) cancers that are also exhibiting MDM2 dependence.  MDM2 dependence may be occurring either through MDM2 gene amplification, protein overexpression, loss of MDM2 regulator or other mechanism.


The MANTRA trial, a randomized, multicenter, open-label, Phase 3 registrational study, is designed to evaluate the safety and efficacy of RAIN-32 compared to trabectedin, a current standard of care, in patients with unresectable or metastatic DD LPS with or without a well-differentiated (WD) LPS component that has progressed on one or more prior systemic therapies, including at least one anthracycline-based therapy. Approximately 160 patients are anticipated to be randomized in a 1:1 ratio to receive milademetan or trabectedin. The primary objective of the trial is to compare progression-free survival (PFS) by blinded independent review between the milademetan treatment arm and the trabectedin control arm. Secondary endpoints include overall survival, PFS by investigator assessment, objective response rate, duration of response, disease control rate, safety and patient reported outcomes. DD LPS patients had been observed to have MDM2 amplification..

Who is eligible?

We recommend that you discuss your clinical trial options with your physician.

  • 18 years of age or older
  • Confirmed DD liposarcoma diagnostic from histology of a biopsy of the tumor, regardless of whether or not the biopsy contains well-differentiated liposarcoma. The participant must be willing to provide either an archival tumor sample at most 3 years old or a fresh pre-treatment sample.
  • The cancer must be either metastatic or a tumor that cannot be surgically removed without significant risk to the life and/or well-being of the participant.
  • Resolution of any clinically relevant toxic effects of prior chemotherapy, surgery, radiotherapy, or hormonal therapy
For more eligibility criteria visit

PATIENT Resources

Basket Study

The MANTRA-2 trial is designed to evaluate the safety and efficacy of milademetan in patients with advanced or metastatic solid tumors refractory or intolerant to standard-of-care therapy and that exhibit wild-type p53 and a prespecified minimum MDM2 gene copy number. Approximately 65 patients are anticipated to be enrolled to receive milademetan. The primary endpoint of the trial is objective response rate as measured by RECIST criteria.  Secondary endpoints include duration of response, disease control rate progression-free survival by investigator assessment, overall survival and, and growth modulation index.

Who is eligible?

We recommend that you discuss your clinical trial options with your physician.

  • I am 18 years of age or older
  • Confirmed diagnosis of a cancer that is a locally advanced or metastatic solid tumor (except brain tumor, liposarcoma, and intimal sarcoma)
  • Already treated with standard therapy appropriate for tumor type and stage of disease or, in the opinion of the Investigator, would be unlikely to tolerate or derive clinically meaningful benefit from appropriate standard-of-care therapy
  • Resolution of any clinically relevant toxic effects of prior chemotherapy, surgery, radiotherapy, or hormonal therapy
  • Tumor DNA testing by the central diagnostic laboratory should reveal the presence of wild-type gene TP53 and at least 12 copies of the proto-gene MDM2
For more eligibility criteria visit

Frequently Asked Questions

How do I get enrolled?

You may visit for our clinical trials currently recruiting patients. All clinical trials have eligibility criteria about who can and cannot participate. Not everyone will qualify to participate in the clinical trial based on the eligibility criteria. To learn more about a specific clinical trial, it is best to contact the clinical study team at the clinical trial site. The clinical study team will provide more details and answer any questions about the clinical trial and on how to get enrolled in the clinical trial.

What does it cost to participate in the clinical trial?

Some health insurance providers will pay some or all of the costs associated with participating in a clinical trial. Most often, the clinical trial site or sponsor of the trial covers the cost of the intervention while the insurance provider pays for routine care. You can ask the clinical study team and your insurance provider in advance to determine which costs are likely to be covered.

Will I be compensated?

In general, trial participants are not paid for participating, but expenses may be covered. The clinical study team will clearly outline any compensation that will be provided during the informed consent process. It is also important for a potential trial participant to ask the clinical study team about payment for expenses or indirect costs of participating in a clinical trial, such as time away from work, travel to and from the clinical trial site during study appointments, etc.

Are There Risks or Side Effects in Clinical Trials?

There are risks associated with participating in clinical trials. The known risks associated with a clinical trial will be described in detail in the informed consent form, which a potential trial participant is asked to review before agreeing to take part in a clinical trial. The major risks will also be explained to a potential trial participant by a member of the clinical study team, who will answer any questions about the clinical trial. Any medical treatment can also carry the potential for side effects for some trial participants. Because clinical trials are research into new areas of treatment, the risks and side effects involved are not always known ahead of time, though efforts have been made to find out what they might be. Before making a decision about whether to participate in a clinical trial, you should carefully evaluate any potential risks or unknowns before deciding to take part.

Expanded Access Policy

Expanded access, also called compassionate use, is a potential pathway for patients with an immediate life-threatening or serious condition to gain early access to an investigational product for treatment outside of clinical trials when no comparable or satisfactory alternative therapy option is available. Rain is committed to developing transformative therapies in areas of significant unmet medical need to enhance the quality of life in cancer patients.  We believe the best way to make our therapies available in a timely manner to patients is through clinical trials. We are conducting clinical trials to assess the safety and efficacy of our investigational products, which if proven successful, will allow us to pursue approvals from regulatory authorities.  Rain believes that participation in our clinical trials is the most timely and appropriate manner to access our investigational products prior to their approval, and the best way to expedite access to[ our drugs for appropriate patients. Therefore, Rain is not providing investigational products through expanded access at this time.   Rain will continue to assess our expanded access policy and provide updates to this website. We are focused on advancing our clinical development programs, and more information about our clinical trials can be found on Please contact us with any questions at