Clinical Results Summary
A clinical study to learn about the effects and safety of PLX3397 in men
with advanced castration-resistant prostate cancer (CRPC) that hadspread to the bone
Protocol number: PLX108-06

Thank You!

Daiichi Sankyo, Inc., the sponsor of this study, would like to thank theparticipants who took part in this study for PLX3397. Each participant helped toadvance medical research for men affected with advanced castration-resistant
prostate cancer (CRPC) that had spread to the bone. CRPC is a type of prostatecancer that keeps growing despite treatment given to reduce testosteronelevels. Their contribution to medicine and healthcare is greatly appreciated.

Important note: This summary only shows the results of a single study. Other studies may have different
findings. Researchers and health authorities look at the results of many studies to understand which
treatments work and how they work. It takes a lot of people in many studies around the world to advance
medical science and healthcare.
Do not use the results of this study to make health decisions. Please talk to a doctor before changing anytreatment you are taking or if you have any questions about these study results.

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What was the main purpose of this study?
Advanced castration-resistant prostate cancer (CRPC) that has spread to thebone

Prostate cancer affects the prostate gland (a small organ in a man’s pelvis). The symptoms of prostate cancer
include pain, tiredness, and problems emptying the bladder and bowels. Prostate cancer that does not
respond to treatment that targets the male sex hormone testosterone is known as castration-resistant
prostate cancer (CRPC). CRPC is considered advanced if it spreads to other parts of the body beyond theprostate.

CRPC that spreads to the bones results in a high count of circulating tumor cells (CTCs). CTCs are individual
cancer cells that have spread beyond the prostate gland and are found floating in the blood. For prostatecancer patients, CTCs are used as a measure to determine how much the cancer has spread.
PLX3397 is a drug being developed for CRPC that has spread to the bones. It acts by blocking the effect oftestosterone on the prostate. In this study, researchers wanted to learn if PLX3397 could be used to reduce
the size of the tumor in participants who have advanced CRPC that has spread to the bones by reducing thenumber of CTCs.

Treatment given in this study
Investigational Treatment
PLX3397
An investigational drug being tested for thetreatment of patients with CRPC whose tumor
cells have spread to the bone and released CTCs
in the blood.

Main goal of this study

The main question the researchers wanted to answer in this study was:

PLX108-06 Clinical Results Summary | 2How long was this study?
An individual participant could have been in this study forabout 9 months.
This study started in May 2012 but was stopped early, inMarch 2013, because not enough participants wereenrolled. When the study was stopped, a report was createdwith the information that was available. This summary isbased on that report.

Who was in this study?
This study included 6 male participants from 2 study sites in the United States. The average age of theparticipants was 71 years.
Participants could take part in this study if they:

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What happened during this study?
This was a Phase 2 study. In Phase 2 studies, the study treatment is given to participants with the disease
condition to gather information about whether or not the study treatment treats patients as expected.
In this study, researchers wanted to learn if PLX3397 was safe and if it was effective in helping participants
with CRPC whose tumor had spread to the bone.
Participants who consented to take part in this study were screened to find out if they were eligible to takepart in this study. Eligible participants received 1000 milligrams of the study treatment on Day 1, which wastaken by mouth. Participants continued to receive the study treatment daily, for 4 weeks. This cycle oftreatment could be continued as long as participants did not show worsening of CRPC, did not have serious
side effects, or asked to be removed from the study.
Researchers collected the participants’ blood for CTC count at screening, at the start of the study, every
4 weeks after the first dose of treatment, and at safety follow-up. CTCs were counted by using a CTC detectionsystem.
The researchers used X-rays to measure the size of the tumor every 8 weeks. They also monitored the healthof the participants throughout the study.

PLX108-06 Clinical Results Summary | 4What were the key results of this study?
This study did not meet its planned enrollment goal of 20 participants by the end of 2012. Therefore, the study
was stopped after 6 participants had joined. No results about how PLX3397 affects CTC count or tumor size
were reported.

What medical problems did the study participants have?
Side effects are medical problems (such as feeling tired) that happened during the study which the study
doctor thought could be related to the treatments in the study. This section provides a summary of side
effects related to the study treatment. The website listed at the end of this summary has more information
about the medical problems that happened in this study.
Side effects are considered serious if they cause death, are life-threatening, cause lasting problems, or require
hospitalization. Some participants stop study treatment because of side effects.

How many participants had serious side effects?

In this study, serious side effects were monitored for 6 participants who took the study treatment.
None of the participants reported serious side effects related to the study treatment. No deaths werereported during the study.

How many participants had non-serious side effects during the study?

All 6 participants reported
non-serious side effects.

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All non-serious side effects reported by participants taking the study treatment are shown below.

Side Effects

Percentage (Number of Participants)

Feeling sick to your stomach

67% (4 out of 6)

Feeling tired

50% (3 out of 6)

Loss of desire to eat

50% (3 out of 6)

Constipation

33% (2 out of 6)

Diarrhoea

33% (2 out of 6)

Blood glucose increased

17% (1 out of 6)

Blood sodium increased

17% (1 out of 6)

Difficulty breathing

17% (1 out of 6)

Increase in liver test value of alanine
aminotransferase in the blood

17% (1 out of 6)

Increase in liver test value of aspartate
aminotransferase in the blood

17% (1 out of 6)

Increase in pancreatic test value oflipase in the blood

17% (1 out of 6)

Increase in protein called creatine
phosphokinase in the blood

17% (1 out of 6)

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Side Effects

Percentage (Number of Participants)

Inflammation of the inner lining of thebody and its organs

17% (1 out of 6)

Low blood platelet count17% (1 out of 6)

Low number of red blood cells

17% (1 out of 6)

Pain in hands and feet

17% (1 out of 6)

Note: platelets are tiny blood cells that help the body form blood clots to stop bleeding.

How many participants had to stop treatment because of side effects?

One participant stopped the study treatment due to an increase in the protein called creatine phosphokinase
in the blood.

How was this study useful for patients and researchers?
This study was planned to help researchers learn if PLX3397 was safe and if it was effective in helping
participants with CRPC whose tumor had spread to the bone. However, since this study was stopped early,
only information about the safety of PLX3397 was collected.
Findings from this study may be used in other studies with PLX3397. Other studies of PLX3397 are ongoing.
Please remember, this summary only shows the results of a single study. Findings from other studies may bedifferent. Please talk to a doctor before changing any treatment you are taking or if you have any questions
about these study results.

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Where can I learn more about this study?
You can find more information about this study on the following website:www.clinicaltrials.gov Use the NCT identifier NCT01499043 in the search field.
Please remember that the results on this website may be presented in a different way. If you were a study
participant and have questions about the results of this study, please speak with the doctor or staff at yourstudy site.
Full study title: A Pilot Study of PLX3397 in
Advanced Castration-Resistant Prostate Cancer(CRPC) Patients with Bone Metastasis and HighCirculating Tumor Cell (CTC) Counts

Sponsor: Daiichi Sankyo Inc.
Sponsor contact information:
211 Mount Airy Road, Basking Ridge, NJ 07920
Email: CTRInfo@dsi.com
Phone number: 1-908-992-6640
Date of this summary: 10 August 2020

This summary was prepared by Kinapse Ltd, a Syneos Health® company.

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