About Prostate Cancer
Prostate cancer is the second most frequent cancer and the fifth leading cause of cancer death in men around the world. Prostate cancer is commonly treated with medications to reduce levels of male hormones in the body (such as testosterone). This medication is called androgen deprivation therapy (ADT). Unfortunately, cancer that initially improves from ADT may eventually become resistant to treatment and continue to progress despite ongoing therapy. When this happens, it is called Castration Resistant Prostate Cancer (CRPC). CRPC is considered metastatic if it has spread to other parts of the body.

About the Study
The TAMARACK study will help us learn if an investigational intravenous (IV) medicine is effective and tolerable for the treatment of metastatic CRPC that has progressed during or after treatment with enzalutamide, abiraterone, or apalutamide in addition to docetaxel.
The study medicine is an antibody with an anti-cancer drug attached, called an antibody-drug conjugate (ADC). Antibodies are proteins produced by the body's immune system to fight infections or kill cancer cells. The antibody portion of the ADC allows the anti-cancer drug to attach to and kill cancer cells. The antibody targets cancer cells specifically, which helps prevent the anti-cancer drug from hurting normal cells.
The study medicine has not been approved for use outside of clinical trials.
Who Can Participate?
This study may be an option for men who
- Are at least 18 years old
- Have been diagnosed with metastatic castration-resistant prostate cancer
- Received treatment with abiraterone, enzalutamide, or apalutamide
- Have not received prior chemotherapy other than docetaxel or cabazitaxel
There are other requirements to participate in the TAMARACK study. Answer a few questions to determine if you meet the initial requirements and get in touch with the study team. If you or your loved one is eligible, they will contact you by phone or email to review additional eligibility criteria, answer any questions, and help determine if this study is suitable.

What to Expect
This study does not contain a placebo (medicine with no active ingredient). All participants will be randomly assigned (like flipping a coin) to receive the study medicine at one of two different dose levels.
The study medicine is given as an infusion (injected directly into a vein using a needle or catheter) once every four weeks. Participants may continue receiving the study medicine for up to two years (26 cycles), or until their cancer worsens, side effects are not tolerable, or they choose to leave the study. During their time in the study, participants will need to attend regular visits so the study team can monitor their prostate cancer and response to treatment. These visits may include health assessments, blood samples, ECGs, and CT/MRI scans.
There is no cost to participate in the TAMARACK study. Additionally, participants may be reimbursed for study-related expenses like meals and travel.
Why Participate?
Before a potential treatment can be approved and made available to the public, it must first be tested in a series of clinical trials. Clinical trials are an essential step in the process of developing new medications, and they are not possible without the participation of volunteers.
By choosing to volunteer in the TAMARACK study, you will help us learn if the study medicine is effective and tolerable for the treatment of metastatic CRPC. The results of this study may help other people living with prostate cancer in the future.

Frequently Asked Questions
How long will I be in this study?
You or your loved one's time in the study will vary depending on how many treatment cycles are completed. Participants may receive the study medicine for a maximum of two years (26 cycles). After a participant's last treatment cycle, the study team will check in with them about every three months for up to six months.
What are the possible benefits of participating in the TAMARACK study?
This study may not provide any direct benefit to you or your loved one. If you or your loved one choose to participate, you or your loved one will receive an investigational medicine being studied to treat prostate cancer. Your prostate cancer and health will be monitored regularly throughout. Additionally, you or your loved one will be contributing to research that will help us learn more about metastatic castration resistant prostate cancer and may help others with prostate cancer in the future.
What are the potential risks of participating?
All research studies and medical treatments come with some risks. The study team will discuss all possible risks with you before you decide to participate.
Are clinical trials safe?
Clinical trials must undergo rigorous reviews and follow strict rules. These rules help to ensure that the rights, safety, and well-being of participants are at the forefront of any study. Before you or your loved one can join any clinical trial, you need to read and sign an Informed Consent Form. This form includes a full explanation of the study, including its potential risks, so you can make an informed decision about whether or not you want to join the study. In addition to having a copy of the Informed Consent form for you to read, a study team member will discuss it with you and answer any questions you have. You should feel free to discuss the study with family, friends, and/or your doctor before you make your decision.
What if the TAMARACK study is not right for me?
Participating in this study is completely optional and up to you. You can choose to leave the study at any time, for any reason. Choosing not to participate will not affect your future medical care or prostate cancer treatment in any way.
Does it cost anything to participate?
No. Participants will receive the investigational or standard-of-care medicine and all study-related assessments and procedures at no cost.
How can I learn more?
Answer a few questions to determine if you or your loved one meet the initial requirements. We will match you to a participating study site in your area. A study team member will contact you to schedule an in-clinic appointment to determine if you meet additional study eligibility criteria. They will be happy to answer any questions you may have.
