Overview

DS-8201a for trEatment of aBc, BRain Mets, And Her2[+] Disease

Status:
Recruiting
Trial end date:
2023-02-01
Target enrollment:
0
Participant gender:
All
Summary
This is a multicenter, international, open-label, single-arm, multicohort, two-stage optimal Simon's design, phase II clinical trial
Phase:
Phase 2
Accepts Healthy Volunteers?
No
Details
Lead Sponsor:
MedSIR
Collaborator:
Daiichi Sankyo, Inc.
Treatments:
Trastuzumab
Criteria
Inclusion Criteria:

1. Signed Informed Consent Form (ICF) prior to participation in any study-related
activities.

2. Male or female patients ≥ 18 years at the time of signing ICF.

3. Eastern Cooperative Oncology Group (ECOG) performance status of 0-1 for Cohorts 1 to 4
and 0-2 for cohort 5.

4. Life expectancy ≥ 12 weeks.

5. Histologically confirmed invasive breast cancer based on local testing on the most
recent analyzed biopsy of the following breast cancer (BC) subtypes per 2018 American
Society of Clinical Oncology (ASCO)/College of American Pathologists (CAP) criteria:

- Cohort 1 and 3: HER2 positive status

- Cohort 4: HER2-low expressing status

- Cohort 2 and 5: both HER2 positive and HER2-low expressing status

Note 1: According to the 2018 ASCO-CAP guidelines, HER2- positive status is defined as HER2
immunohistochemistry (IHC) 3+, in situ hybridization (ISH) ≥ 2.0, or average HER2 copy
number ≥ 6.0 signals. HER2-low expressing status defined as IHC 2+ / ISH-negative or IHC 1+
(ISH-negative or untested).

Note 2: Central confirmation of HER2 is not required for study entry. However, tissue
blocks, or slides, must be submitted to confirm BC subtype by a Sponsor-designated central
laboratory retrospectively.

Unresectable locally advanced or metastatic disease documented by computerized tomography
(CT) scan or magnetic resonance imaging (MRI) that is not amenable to resection with
curative intent.

7. At least one brain lesion needed to be measurable (≥10 mm on T1-weighted,
gadolinium-enhanced MRI) (study cohorts 2 to 4) or leptomeningeal carcinomatosis (LMC) with
positive cerebrospinal fluid (CSF) cytology (study cohort 5).

- Study cohort 1: History of BM that are non-progressing after WBRT and/or SRS and or
surgery.

- Study cohort 2: Presence of asymptomatic BM without clinical requirement for local
intervention (WBRT and/or SRS and/or surgery).

- Study cohorts 3 and 4: Evidence of new and/or progressive BM following previous WBRT
and/or SRS and/or surgery.

- Study cohort 5: Evidence of LMC with positive CSF cytology.

8. Previous treatments:

- For HER2-positive patients have been previously treated with a taxane and at least one
HER2-targeted therapy in the advanced scenario.

- For HER2-low-expressing patients that also are endocrine receptor negative must have
been previously treated with at least one chemotherapy regimen. If endocrine receptor
positive, patients must have been previously treated with at least one chemotherapy
and one endocrine regimen in the metastatic setting.

9. Patients must agree to collection of blood samples at the time of inclusion, at
cycle 2 of treatment, and upon progression or study termination.

Note: In study cohort 5: Patients must agree to perform spinal taps or must be willing to
have an Ommaya reservoir placed for CSF assessment, at baseline, every three weeks for 12
weeks (corresponding to the first 5 cycles of treatment) and every six weeks thereafter.

10. Willingness and ability to provide tumor biopsy (if feasible) from metastatic lesions
or breast primary tumor both at the time of the inclusion and after disease progression in
order to perform exploratory studies.

Note: If feasible, patients should provide a tissue sample at baseline from metastases
amenable to biopsy (at sites of locoregional recurrence [skin, chest wall, breast or lymph
nodes], or distant recurrence [bone, liver, lung or abdomen]) or as alternative from breast
primary tumor, that will be obtained between progression to the prior regimen and inclusion
in the study. Patients for whom tissue sample cannot be obtained (e.g., non-measurable
disease, inaccessible tumor or subject safety concern) may submit an archived metastatic
tumor specimen only upon agreement from the Sponsor. If feasible, an additional tissue
sample should be collected at the end of treatment visit for patients who discontinue
treatment due to disease progression.

11. Patients should have left ventricular ejection fraction (LVEF) ≥ 50% by either an
echocardiogram (ECHO) or multigated acquisition (MUGA) scan within 28 days before
enrolment.

12. Adequate hematologic and organ function within 14 days before the first study treatment
on Day 1 of Cycle 1, defined by the following:

- Hematological: White blood cell (WBC) count 3 3.0 x 109/L, absolute neutrophil count
(ANC) 3 1.5 x 109/L, platelet count 3 100.0 x109/L, and hemoglobin 3 9.0 g/dL.
(Platelet, red blood cell transfusion as well as G-CSF administration are not allowed
within 1 week of screening assessments).

Hepatic: Bilirubin ≤ 1.5 times the upper limit of normal (× ULN) (< 3 x ULN in the case of
documented Gilbert's disease and/or liver metastases); aspartate transaminase (AST) and
alanine transaminase (ALT) ≤ 3 × ULN (in the case of liver metastases ≤ 5 × ULN); alkaline
phosphatase (ALP) ≤ 2 × ULN (≤ 5 × ULN in the case of liver and/or bone metastases ≤ 5 ×
ULN), serum albumin 3 2.5 g/dL

• Renal: Serum creatinine £ 1.5 × ULN or creatinine clearance ≥ 30 mL/min based on
Cockcroft-Gault equation (*Cockcroft-Gault equation: ([{140 - age in years} × {ACTUAL
WEIGHT in kg}] divided by [{72 × serum creatinine in mg/dL} multiplied by 0.85 if female]))
Coagulation: International Normalized Ratio (INR)/Prothrombin Time (PT) and activated
Partial Thromboplastin Time (aPTT) ≤ 1.5 × ULN (except for patients receiving
anticoagulation therapy).

Note: Patients receiving heparin treatment should have an aPTT) between 1.5 and 2.5 × ULN
(or patient value before starting heparin treatment). Patients receiving coumarin
derivatives should have an INR between 2.0 and 3.0 assessed in two consecutive measurements
one to four days apart. Patients should be on a stable anticoagulant regimen.

13. Has adequate treatment washout period before enrollment, as indicated:

1. Major surgery: > 4 weeks;

2. Radiation therapy: > 4 weeks (palliative stereotactic radiation therapy to other areas
≥ 2 weeks);

3. Anticancer systemic treatment (including immunotherapy, retinoid therapy, hormonal
therapy): ≥ 3 weeks (≥ 2 weeks or 5 half-lives, whichever is longer, for
small-molecule targeted agents such as 5-fluorouracil-based agents, folinate agents,
weekly paclitaxel; ≥ 6 weeks for nitrosureas or mitomycin C);

4. Antibody based therapy: 3 4 weeks;

5. Chloroquine/Hydroxychloroquine>14 days

14. Resolutionofallacutetoxiceffectsofprioranti-cancertherapyto grade £ 1 as
determined by the National Cancer Institute-Common Terminology Criteria for Adverse
Events (NCI-CTCAE) v.5.0 (except for alopecia or other toxicities). Subjects with
chronic Grade 2 toxicities may be eligible per the discretion of the Investigator
after consultation with the Sponsor Medical Monitor or designee (e.g., Grade 2
chemotherapy-induced neuropathy).

15. Male and female subjects of reproductive/childbearing potential must agree to use
a highly effective form of contraception or avoid intercourse during and upon
completion of the study and for at least 7 months for females and 4 months for males
after the last dose of study drug. Methods considered as highly effective methods of
contraception include:

• Combined (estrogen and progestogen containing) hormonal contraception associated
with inhibition of ovulation: i. Oral ii. Intravaginal iii. Transdermal

• Progestogen-only hormonal contraception associated with inhibition of ovulation: iv.
Oral v. Injectable vi. Implantable

• Intrauterine device (IUD)

• Intrauterine hormone-releasing system (IUS)

• Bilateral tubal occlusion

- Vasectomized partner

- Complete sexual abstinence defined as refraining from heterosexual intercourse
during and upon completion of the study and for at least 7 months after the last
dose of study drug. Periodic abstinence (calendar, symptothermal, post-ovulation
methods) is not an acceptable method of contraception.

Note: Non-child-bearing potential defined as pre-menopausal females with a documented
tubal ligation or hysterectomy; or postmenopausal defined as 12 months of spontaneous
amenorrhea (in questionable cases, a blood sample with simultaneous
follicle-stimulating hormone [FSH] > 40 mIU/mL and estradiol < 40 pg/mL [< 147 pmol/L]
is confirmatory).

16. Male subjects must agree to not freeze or donate sperm starting at Screening and
throughout the study period, and at least 7months after the final study drug
administration. Preservation of sperm should be considered prior to enrolment in this
study.

17. Female subjects must agree to not donate, or retrieve for their own use, ova from
the time of Screening and throughout the study treatment period, and for at least 7
months after the final study drug administration.

18. Patients who are willing and able to comply with scheduled visits, treatment plan,
laboratory tests, post-treatment follow-up and other study procedures.

Exclusion Criteria:

Patients will be excluded from the study if they meet ANY of the following criteria:

1. Inability to comply with study and follow-up procedures.

2. Previous treatment with trastuzumab deruxtecan (DS-8201a) or any other antibody
drug conjugate (ADC) which consists of an exatecan derivative that is a
topoisomerase 1 inhibitor.

3. Medical history of myocardial infarction within 6 months before enrollment,
symptomatic congestive heart failure (New York Heart Association Class II to IV),
troponin levels consistent with myocardial infarction within 28 days prior to
enrollment.

4. Corrected QT interval (QTc) prolongation to > 470 ms (females) or >450 ms (males)
based on average of the screening triplicate12- lead ECG.

5. History of (non-infectious) interstitial lung disease (ILD) that required
steroids, has current ILD, or where suspected ILD cannot be ruled out by imaging
at screening.

6. Clinically significant corneal disease in the opinion of the Investigator.

7. Spinal cord compression.

8. Multiple primary malignancies within 3 years, except adequately resected
non-melanoma skin cancer, curatively treated in-situ disease, other solid tumors
curatively treated, or contralateral breast cancer.

9. History of severe hypersensitivity reactions to either the drug substances or
inactive ingredients in the drug product.

10. History of severe hypersensitivity reactions to other monoclonal antibodies.

11. Uncontrolled infection requiring IV antibiotics, antivirals, or antifungals.

12. Patients with substance abuse or any other medical conditions such as clinically
significant cardiac or psychological conditions, that may, in the opinion of the
investigator, interfere with the subject's participation in the clinical study or
evaluation of the clinical study results.

13. Known human immunodeficiency virus (HIV) infection, or active hepatitis B or C
infection. Subjects should be tested for HIV prior to enrollment if required by
local regulations or institutional review board (IRB)/ethics committee (EC).

14. Female patients who are pregnant or breastfeeding or planning to become pregnant.

15. No other systemic therapy for metastatic disease including chemotherapy,
immunotherapy, targeted therapy (small molecules/ monoclonal antibodies), or
endocrine therapy

16. Major surgery (defined as requiring general anesthesia) or significant traumatic
injury within 4 weeks of start of study drug, or patients who have not recovered
from the side effects of any major surgery, or patients who may require major
surgery during the study.

17. Radiotherapy within 4 weeks or limited-field palliative radiotherapy within 2
weeks prior to study enrolment, or patients who have not recovered from
radiotherapy-related toxicities to baseline or grade ≤ 1 and/or from whom ≥ 25%
of the bone marrow has been previously irradiated.

18. Use of concurrent investigational agents or other concomitant anticancer
therapies.

19. Use of intrathecal therapy for LMC

20. Active bleeding diathesis, previous history of bleeding diathesis, or chronic
anti-coagulation treatment (the use of low molecular weight heparin is allowed as
soon as it is used as prophylaxis intention).

21. Serious concomitant systemic disorder (e.g., active infection including HIV,
active hepatitis, liver cirrhosis, end stage chronic renal disease) incompatible
with the study (at the discretion of investigator).

22. Any of the following within 6 months of enrollment: severe/unstable angina,
ongoing cardiac dysrhythmias of NCI-CTCAE v.5.0 grade 32, coronary/peripheral
artery bypass graft, cerebrovascular accident including transient ischemic
attack, or symptomatic pulmonary embolism.

23. Uncontrolled electrolyte disorders of NCI-CTCAE v.5.0 grade ≥ 2.

24. Clinically severe pulmonary compromise resulting from intercurrent pulmonary
illnesses including, but not limited to, any underlying pulmonary disorder (i.e.
pulmonary emboli within three months of the study enrollment, severe asthma,
severe COPD, restrictive lung disease, pleural effusion etc.), and any
autoimmune, connective tissue or inflammatory disorders with potential pulmonary
involvement (i.e. Rheumatoid arthritis, Sjogren's, sarcoidosis etc.), or prior
pneumonectomy.