This is a randomized phase II, open label, two arm study, evaluating the efficacy of panitumumab in combination with Trifluridine-Tipiracilas third line therapy, after a first line containing an anti-EGFR agent panitumumab(at least 70% of study population) or cetuximab in metastatic colorectal cancer (mCRC) patients.

This is a randomized phase II, open label, two arm study, evaluating the efficacy of panitumumab in combination with Trifluridine-Tipiracilas third line therapy, after a first line containing an anti-EGFR agent panitumumab(at least 70% of study population) or cetuximab. The primary objective is to evaluate the efficacy [as defined by progression free survival (PFS)] of panitumumab in combination with Trifluridine-Tipiracil in pretreated mCRC patients. The secondary objective is to evaluate the objective response rate (ORR), overall survival (OS) and safety. Patients will be randomized in a 1:1 ratio to receive:

Arm A: Trifluridine-Tipiracil Arm B: Panitumumab + Trifluridine-Tipiracil A total of 112 patients will be enrolled. Treatment will be administered in 28-days cycles until disease progression, unacceptable toxicity, withdrawal of consent or death due to any cause.

All patients will be closely monitored for safety and tolerability during all cycles of therapy, at the treatment discontinuation visit, and during the follow-up period. The National Cancer Institute (NCI) Common Terminology Criteria for Adverse Events (CTCAE), version 5.0 (v. 5.0) will be used to characterize the toxicity profile of the study treatments on all patients. Patients who discontinue treatment for reasons other than disease progression (e.g., toxicity) will continue scheduled tumor assessments until disease progression, withdrawal of consent, study termination by Sponsor, or death, whichever occurs first. In the absence of disease progression, tumor assessments should continue regardless of whether patients start a new anti-cancer therapy, unless consent is withdrawn. All patients will be followed for survival unless consent is withdrawn.

Inclusion Criteria:

• Histologically proven diagnosis of colorectal adenocarcinoma
• Diagnosis of metastatic disease
• RAS (NRAS and KRAS exon 2,3 and 4) wild-type in tissue at initial diagnosis
• Efficacy of a first line therapy containing an anti-EGFR agent (panitumumab or ceuximab) with a major response achieved (complete or partial response)
• Progression after a second line therapy
• Available and adequate baseline tumour tissue sample
• Measurable disease according to RECIST criteria v1.1
• Male or female patients > 18 years of age
• ECOG Performance Status 0-1
• Life expectancy of at least 3 months
• Adequate bone marrow, liver and renal function
• If female and of childbearing potential, have a negative result on a pregnancy test performed a maximum of 14 days before initiation of study treatment
• If female and of childbearing potential, or if male, agreement to use adequate contraception (eg, abstinence, intrauterine device, oral contraceptive, or double-barrier method)
• Signed informed consent

Exclusion Criteria:

• Any contraindication to use Trifluridine - Tipiracil or Panitumumab
• More than two previous lines of treatment
• Active uncontrolled infections
• Past or current history of malignancies other than colorectal carcinoma, except for curatively treated basal and squamous cell carcinoma of the skin or in situ carcinoma of the cervix
• Pregnancy
• Breastfeeding
• Interstitial lung disease or pulmonary fibrosis
• Grade III or IV heart failure (NYHA classification)