Inclusion Criteria:

1. Patients ≥18 years with histology-proven advanced, or R/M ACC.

2. Evidence of locally advanced disease not amenable to curative intent surgery or
radiotherapy, or recurrent/metastatic disease

3. ACC-I subtype defined by at least one of the following:

1. Presence of an activating NOTCH mutation per in-house or any CLIA-certified or
commercially available next-generation sequencing assay

2. Solid histology and clinical course characterized by < 3 years from diagnosis
to initial recurrence or progression or de novo metastatic disease with
extra-pulmonary metastasis

3. Negative TP63 tumor expression by IHC (<10% of tumor cells)

4. Measurable disease per RECIST 1.1

5. Performance status ECOG of 0 or 1

6. Patient has provided informed consent.

7. Adequate bone marrow, hepatic, and renal function with the most recent laboratory
assessments 8. Contraceptive use by the participant or the participant's partner
should be consistent with local regulations regarding the methods of contraception
for those participating in clinical studies.

(a) Male participants: (i) Non-sterilized male participants who are sexually active
with a female partner of childbearing potential must use a male condom (plus
spermicide, if available) from enrollment throughout the study and for 8 months
following the last dose of study drug. It is strongly recommended for the female
partner of a male participant to also use a highly effective method of contraception
throughout this period, as described in Table 3. In addition, male participants must
refrain from sperm donation while on study and for 8 months (5 half-lives plus 6
months) following the last dose of study drug.

(b) Female participants: (i) Females of childbearing potential must have a negative
urine or serum pregnancy test prior to receiving the first dose of study drug. If
the urine test is positive or cannot be confirmed as negative, a serum pregnancy
test will be required.

(ii) Female participants of childbearing potential who are sexually active with a
non-sterilized male partner must agree to use one highly effective method of birth
control (defined as one that can achieve a failure rate of less than 1% per year when
used consistently and correctly, from enrollment throughout the study and for 8 months
following the last dose of study drug. It is strongly recommended for the male partner of
a female participant to also use male condom (plus spermicide, if available) throughout
this period. Cessation of contraception after this point should be discussed with a
responsible physician.

9. Patients can be treatment-naïve or have received up to 3 lines of prior systemic
therapy in the setting ofR/M disease, however, a maximum of two prior lines of
chemotherapy or antibody-drug conjugate (ADC) are allowed. Exceptions include prior
B7-H4-targeting ADC or any prior agent with a topoisomerase inhibitor

1 mode of action; those represent exclusion criteria (exclusion criteria #18).

Exclusion Criteria:

1. Treatment with any of the following as detailed below in Table 2:

Table 2 . Washout period from prior therapies Treatment Washout period Nitrosourea
or mitomycin C Within 6 weeks prior to the first dose of study intervention Any
investigational agents or study drugs from a previous clinical study Within 5
half-lives or 28 days (whichever is shorter) prior to the first dose of study drug
Any other anticancer treatment Within the following time periods prior to the first
dose of study intervention: Cytotoxic treatment: 21 days Non-cytotoxic drugs: 21
days or 5 half-lives (whichever is shorter) Biological products including
immuno-oncology agents: 28 days Radiotherapy Wide field of radiation (including
whole brain radiotherapy) within 4 weeks or limited field radiotherapy (including
stereotactic radiotherapy or gamma-knife) for palliation is allowed up to 14 days
prior to the first dose of study intervention. Participants who have not recovered
from radiotherapy-related toxicity will not be eligible Major surgery (as defined by
the Investigator) At least 28 days prior to the first dose of study intervention

2. Unresolved toxicities of Grade ≥ 2 (National Cancer Institute [NCI] Common
Terminology Criteria for Adverse Events [CTCAE version 5.0) from prior therapy
(excluding vitiligo, alopecia, endocrine disorders that are controlled with
replacement hormone therapy, and lymphopenia unless it is accompanied by clinical
signs of infection or the indication for prophylaxis with
antibiotic/antiviral/antifungal therapy). Participants with chemotherapy-induced
Grade 2 neuropathy may be eligible at discretion of the Investigator.

3. Active infection, including tuberculosis, SARS-CoV-2, and known infections with
hepatitis B virus (HBV), hepatitis C virus (HCV) or human immunodeficiency.
Participants with a past or resolved HBV/HCV infection are eligible if all the
following criteria are met:

1. Negative for HBsAg and positive for total hepatitis B core antibody (anti-HBc)
or Positive for HBsAg, but for > 6 months have had normal transaminases and HBV
DNA levels between 0-2000 IU/mL (inactive carrier state) and willing to start
and maintain antiviral treatment for at least the duration of the study.

2. HBV DNA levels > 2000 IU/mL but on prophylactic antiviral treatment for the
past 3 months and will maintain the antiviral treatment during the study.

3. Participants testing positive for HCV antibody are eligible only if the
polymerase chain reaction test result is negative for HCV RNA.

4. Has a history of (non-infectious) ILD/pneumonitis that required steroids, has
current ILD/pneumonitis, or where suspected ILD/pneumonitis cannot be ruled out by
imaging at screening.

5. Has clinically severe pulmonary compromise resulting from intercurrent pulmonary
illnesses including, but not limited to, any underlying pulmonary disorder or any
autoimmune, connective tissue or inflammatory disorders with pulmonary involvement
or prior pneumonectomy (complete) or require supplemental oxygen (including
intermittent or discretionary use).

6. Patients with history of myelodysplastic syndrome (MDS)/acute myeloid leukaemia
(AML) or with features suggestive of MDS/AML (as determined by prior diagnostic
investigation). Specific screening for MDS/AML is not required.

7. Participants with any of the following cardiac criteria:

1. History of clinically significant arrhythmia (such as multifocal premature
ventricular contractions, bigeminy, trigeminy, ventricular tachycardia), which
is symptomatic or requires treatment (NCI CTCAE version 5.0 Grade 3);
symptomatic or uncontrolled atrial fibrillation despite treatment, or
asymptomatic sustained ventricular tachycardia.

NOTE: abnormalities in serum electrolytes that can increase the risk of
arrhythmic events (ie, sodium, potassium, calcium, magnesium) should be
corrected before starting the study intervention

2. Uncontrolled hypertension.

3. Acute coronary syndrome/acute myocardial infarction, unstable angina pectoris,
coronary intervention procedure with percutaneous coronary intervention, or
coronary artery bypass grafting within 6 months of the start of study
treatment.

4. History of brain perfusion problems (eg, carotid stenosis) or stroke, or
transient ischemic attack in the last 6 months prior to screening.

5. Symptomatic heart failure (as defined by New York Heart Association class ≥ 2).

6. Prior or current cardiomyopathy.

7. Severe valvular heart disease.

8. Resting corrected QT interval using Fridericia's formula (QTcF) > 470 msec

9. Any factors that increase the risk of corrected QT (interval) (QTc)
prolongation or risk of arrhythmic events such as heart failure, congenital
long QT syndrome, family history of long QT syndrome or unexplained sudden
death under 40 years of age.

10. Concomitant medications known to prolong QTc should be used with caution and
cannot be used starting with the first dose of study intervention or during the
scheduled ECG assessments (see << https://www.crediblemeds.org/ >>).

8. Active CNS disease (patients with asymptomatic or treated CNS lesions who have been
off corticosteroids, radiation, or other CNS-directed therapy for at least 4 weeks
prior to start of study treatment are not considered active)

9. Uncontrolled intercurrent illness within the last 12 months of start of study
treatment, including but not limited to serious chronic GI conditions associated
with diarrhea, or psychiatric illness/social situations that would limit compliance
with study requirement, substantially increase risk of incurring AEs or compromise
the ability of the participant to give written informed consent.

10. Has substance abuse or any other medical conditions that would increase the safety
risk to the participant or interfere with participation of the participant or
evaluation of the clinical study in the opinion of the Investigator.

11. Receipt of live attenuated vaccine within 30 days prior to the first dose of study
intervention. Note:

Participants, if enrolled, should not receive live attenuated vaccine whilst
receiving study intervention and up to 30 days after the last dose of study
intervention. Participants can receive COVID-19 vaccines, at the discretion of the
Investigator, following a benefit/risk evaluation for the individual participant and
in accordance with local rules and regulations and vaccination guidelines.

Note: If a COVID-19 vaccine is administered it should be done > 72 hours prior to
study intervention initiation.

12. For women only - currently pregnant (confirmed with positive pregnancy test),
lactating, breastfeeding, or intend to become pregnant during the study.

13. Red blood cell transfusion dependence, defined as requiring more than 2 units of
packed RBC transfusions during the 4-week period prior to screening.

14. Current participation in another interventional clinical study

15. History of previous malignancy other than malignancy treated with curative intent
and low risk of recurrence. Patients with the following diagnoses represents an
exception and may enroll if ≥ 2 years with no evidence of active disease before the
first dose of the study drug or if treatment is not indicated:

1. Non-melanoma skin cancers with no current evidence of disease

2. Melanoma in situ with no current evidence of disease

3. Treated or localized, low-risk, cancer of the prostate with prostate-specific
antigen of <1 ng/mL

4. Treated or localized well-differentiated thyroid cancer (stage I)

5. Cervical carcinoma in situ

6. Treated ductal/lobular carcinoma in situ of the breast

7. Treated or localized, low grade, renal cell carcinoma (stage I)

16. Known hypersensitivity to any of the study drugs, the metabolites, or formulation
excipient

17. Cognitively impaired patients who are incompetent to consent.

18. Prior exposure to a B7-H4 targeting ADC, or any prior agent with a topoisomerase
inhibitor 1 mode of action.