A Study to Investigate ALE.P03 as Monotherapy in Adult Patients With Selected Advanced or Metastatic CLDN1+ Solid Tumors

Inclusion Criteria:

• Have histologically and cytologically metastatic confirmed advanced or metastaticcolorectal cancer, intrahepatic cholangiocarcinoma, squamous non-small cell lungcancer, urothelial carcinoma, and cervical squamous cell carcinoma.

• Have documented radiological disease progression at study entry.

• Have provided tissue for CLDN1 (Claudin-1) analysis in a central laboratory.

Phase I Dose Escalation:

• Received and being refractory/intolerant to available systemic standard of care (SOC) regimens (based on local institutional guidelines) for advanced disease.

Phase I RDE and Phase II:

• Received 1-2 available systemic SOC regimens (based on local institutionalguidelines) for advanced disease and being refractory or intolerant to treatment.

• Patients with actionable oncogenic drivers: received feasible targeted therapy.

Applicable for Phase I Dose Escalation, Phase I RDE and Phase II:

• Measurable disease per RECIST 1.1, as determined by the site.

• Have a performance status of 0 or 1 on the Eastern Cooperative Oncology GroupsPerformance Status.

• Demonstrate adequate bone marrow and organ function as per the protocol.

Exclusion Criteria:

• SqNSCLC and CSCC: diagnosed with a tumor of predominantly non-squamous histologyresult or adenocarcinoma.

• Has received antineoplastic therapies prior to study intervention within specifiedtime frame.

• Has rapidly progressing disease.

• Has known active central nervous system metastases and/or carcinomatous meningitis.

• Has a history of (non-infectious) interstitial lung disease/pneumonitis thatrequired steroids or current symptomatic or clinically significant pneumonitisrequiring steroids and/or immunosuppressive therapies.

• Has clinically significant gastrointestinal bleeding.

• Has an active infection requiring systemic treatment.

• Has a history or current evidence of any condition, therapy, or laboratoryabnormality that might confound the results of the clinical study.