Persistent challenges have been encountered in patient recruitment, difficulty in identifying a sufficient number of eligible subjects. The decision to terminate the study was not based on any safety concerns. Benefit-risk profile of IP unchanged.

This is an open label, single-centre phase 1/2 study involving a single dose of Temferon, an investigational Advanced Therapy Medicinal Product (ATMP), to treat patients with metastatic clear cell renal cell carcinoma (RCC) with evidence of disease progression following at least two lines of standard of care (SoC) treatments.

During Part A (Phase 1) of the study, Temferon will be administered to up to 12 patients, who are going to be split into two cohorts according to immune checkpoint inhibitor -ICI- therapy received in the six months prior to entry into the study, with a histologically confirmed diagnosis of metastatic RCC and evidence of disease progression following at least two lines of SoC treatments.

At D+30 after Temferon, patients will start to receive pembrolizumab providing they have not received ICI in the 6 months prior to entry into the study. Patients allocated to pembrolizumab will receive pembrolizumab 400mg IV every 6 weeks commencing at D+30.

In the event that a patient has received ICI in the 6 months prior to study entry, they will be allocated to the cabozantinib arm. Patients allocated to cabozantinib, will initiate treatment with 40mg QD once PD occurs as assessed at D+30 or at subsequent visits.

Inclusion Criteria:

• Patient aged between 18 - 70 years old
• Women of childbearing potential must have a negative pregnancy test at screening and agree to use two distinct acceptable methods of contraception (which may include partner contraception) for the duration of the study
• Men with partners of childbearing potential must be willing to use acceptable barrier contraceptive method during the trial or have undergone a vasectomy at least 6 months prior to study entry and confirmed by semen analysis
• Adequate cardiac, renal, hepatic, pulmonary, and hematologic function
• Patient able and willing to provide written informed consent and comply with study protocol and procedures
• Histologically confirmed diagnosis of unresectable, locally advanced/metastatic RCC with clear cell component, with or without sarcomatoid features
• Presence of a disease burden sufficiently large to permit biopsy
• Disease progression following approved standard of care treatments for metastatic disease
• ECOG PS 0-1
• Measurable disease at physical examination or at imaging assessment according to RECIST 1.1 criteria

Exclusion Criteria:

• Use of investigational agents or procedures in the 4 weeks prior to study enrolment (6 weeks for long-acting agents) or receipt of an experimental gene therapy product in the past 2 years
• History of current evidence of neuropsychiatric illness
• History of severe cardiovascular disease
• Evidence of haematological neoplasm
• Active alcohol or substance abuse within 6 months of the study
• Current pregnancy or lactation
• Expected to undergo a surgical intervention during the first 3 months of the study
• Known bleeding diathesis or history of abnormal/severe bleeding or any other known coagulation abnormalities that would contraindication a tissue biopsy, active treatment with anticoagulants.
• New CNS or rapidly growing metastases or carcinomatous meningitis
• Presence of hepatic metastases
• Previous allogenic bone marrow, renal, liver transplant
• Prior use of immunosuppressives in the previous 4 weeks prior to enrolment
• Clinically relevant active viral, bacterial or fungal infection
• Active autoimmune disease requiring disease modifying treatment.