Study to Assess AFM24 in Advanced Solid Cancers

Inclusion Criteria:

* Adequate organ function
* Phase 1: Histologically or cytologically confirmed advanced or metastatic solid malignancies that are known to express EGFR
* Phase 1: Previously treated with ≥ 1 lines of anticancer therapy and have documented disease progression during or after their most recent line of anticancer therapy. In addition, either there is no further SOC therapy for the patient or the remaining SOC therapies are deemed not appropriate for the patient by the Investigator.
* Phase 1: Patients must have at least one tumor site that is accessible to biopsy
* Phase 2a: Measurable disease per RECIST 1.1
* Phase 2a: Histologically confirmed advanced or metastatic EGFR+ malignancies for each expansion cohorts:
* Colorectal Cancer (MSS), KRAS-wildtype: disease has progressed after ≥ 2 prior lines of therapy which must have included oxaliplatin, fluoropyrimidine, bevacizumab, and an anti-EGFR therapy
* ccRCC: disease has progressed after ≥ 2 prior lines of therapy which must have included a TKI and a checkpoint inhibitor
* metastatic NSCLC, EGFRmut: disease has progressed on/after after ≥ 1 prior lines of therapy for advanced disease including ≥ 1 prior TKI approved for EGFR mut NSCLC

Exclusion Criteria:

* Treatment with systemic anticancer therapy within 4 weeks of the first dose of study drug (6 weeks if therapy was mitomycin C and/or nitrosoureas), or within 5 half-lives of the agent if half-life is known and it is shorter, before first dose of study drug. Anticancer therapies include cytotoxic chemotherapy, targeted inhibitors, and immunotherapies, but do not include hormonal therapy or radiotherapy.
* Radiation therapy within 2 weeks before 1st dose of study drug or unresolved toxicity from previous radiotherapy.
* History of any other malignancy known to be active, with the exception of completely removed in situ cervical intra-epithelial neoplasia, non-melanoma skin cancer, DCIS, early stage prostate cancer that has been adequately treated, and other cancers from which the patient has been disease free for 3 years or longer.
* Currently participating in a study and receiving study therapy, or participated in a study of an investigational agent and received study therapy or used an investigational device within 4 weeks of the first dose of study treatment.