Evaluate the Safety, Tolerability, Biodistribution and Anti Tumour Activity of 177LU-OPS201 With Companion Imaging 68Ga-OPS202 PET/CT in Previously Treated Subjects With Locally Advanced or Metastatic Cancers Expressing Somatostatin Receptor 2 (SSTR2)

Inclusion Criteria:

- Consenting adults of Eastern Cooperative Oncology Group (ECOG) Performance Status 0 or
1

- Histologically confirmed locally advanced or metastatic disease that has progressed
under or after, failed to respond to, or are intolerant or have a contraindication to
available Standard of Care (SoC) treatment options as per the assessment of the
investigator; initially, subjects with the disease below may be considered:

1. Subjects with Extensive Disease (ED-SCLC) that have progressed on or after
platinum-based chemotherapy or Limited Disease (LD-SCLC) that have progressed and
for which subject has exhausted standard treatment options; subjects may have
received prior immunotherapy.

2. Subjects with Human Epidermal Growth Factor Receptor (HR+)/(HER2-) metastatic BC
after a failure of prior standard-of-care treatments and who have received, if
indicated, at least one line of hormonal therapy, Cyclin-dependent kinase
(CDK4/6) inhibitor for advanced or metastatic disease and at least one line of
chemotherapy for metastatic disease; subjects with a Breast Cancer (BRCA)-mutated
metastatic disease who may have received a Poly adenosine diphosphate ribose
polymerase (PARP) inhibitor, if available, are eligible; prior adjuvant hormonal
treatment and prior adjuvant chemotherapy are allowed.

- Documented progressive disease (radiological, based on RECIST v1.1) within 3 months
prior to first study drug administration. All images should be sent to the Imaging
core laboratory (ICL).

- Adequate organ function determined within 21 days prior to 177Lu-OPS201
administration, defined as follows:

- Haematological: white blood cells (WBC) ≥3000/μL, with absolute neutrophil count
≥1000/μL, platelet ≥100,000/μL and haemoglobin ≥9 g/dL (without a need for
hematopoietic growth factor or transfusion support).

- Renal: Estimated glomerular filtration rate (eGFR) ≥55 mL/minute

- Hepatic: total serum bilirubin ≤2×ULN; aspartate aminotransferase/ alanine
aminotransferase ≤2.5×ULN (≤5×ULN if a subject has liver metastases)

- Formalin fixed paraffin embedded tumour sample (archival tumour sample obtained within
21 days prior to the start of study treatment) from the primary or metastatic lesion
OR is willing to undergo newly obtained biopsy prior to the first dose of study
treatment. Subjects who are unable to provide acceptable tissue may not be enrolled
unless there has been prior agreement with the sponsor.

- 68Ga OPS202 uptake in the target tissue (a primary tumour, lymph nodes longest
diameter on PET/CT as confirmed by a central reader.

- Radiologically, ≥50% matching between the lesions detected on 68Ga OPS202-PET/CT and
on 18F-fluorodeoxyglucose (18F-FDG)-PET/CT as confirmed by central reader

Exclusion Criteria:

- Male subjects with BC.

- Unstable central nervous system metastasis

- Centrally located tumours with radiographic evidence (CT or MRI) of cavitary or
necrotic lesions or focal invasion of major blood vessels.

- Previously received external beam irradiation to a field that includes more than 30%
of the Bone marrow (BM).

- Previous chemotherapy within a cycle interval, curative radiotherapy within 4 weeks or
palliative radiotherapy within 7 days prior to Investigational radiopharmaceutical
product (IRPP) administration.

- Prior treatment with any other investigational medicinal product (IMP) within five
half-lives of the previous IMP or within 2 weeks, if the previous compound is a
mechanism-based molecularly targeted agent whose half-life is not well characterized
and toxicities have not resolved from Grade 2 or higher prior to IRPP administration.

- Any unresolved NCI-CTCAE Grade 2 or higher toxicity (except alopecia and Grade 2
platinum-therapy related neuropathy) from previous antitumour treatment and/or
medical/surgical procedures/interventions.

- Nephrectomy, renal transplant or concomitant nephrotoxic therapy putting the subject
at high risk of renal toxicity during the study as assessed by the investigator.

- Any significant medical or surgical condition that would affect safety or the
assessment of efficacy or the ability of a person to comply with the protocol.

- Any condition that precludes the proper performance of PET and/or CT scan:

1. subjects who are not able to tolerate the CT contrast agent.

2. subjects with metal implants or arthroplasty, or any other objects that might
interfere with the PET and/or CT analysis.

3. subjects unable to raise arms for prolonged imaging purposes.

4. subjects unable to lie still for the entire imaging time.

5. subjects weighing greater than 130 kg (287 lb).

- Pregnant or lactating female. Female subject of childbearing potential who is
unwilling to use acceptable method(s) of effective contraception during study
treatment and through 6 months after the last dose of 177Lu-OPS201.

- Male subject who is unwilling to use acceptable method of effective contraception
during treatment and through 6 months after the last dose of 177Lu-OPS201.