The tumour-targeting human L19-IL2 immunocytokine: preclinical safety studies, phase I clinical trial in patients with solid tumours and expansion into patients with advanced renal cell carcinoma

Eur J Cancer. 2010 Nov;46(16):2926-35. doi: 10.1016/j.ejca.2010.07.033. Epub 2010 Aug 24.


Background: L19-IL2, a tumour-targeting immunocytokine composed of the recombinant human antibody fragment L19 (specific to the alternatively-spliced EDB domain of fibronectin, a well characterised marker of tumour neo-vasculature) and of human IL2, has demonstrated strong therapeutic activity in animal cancer models. This phase I/II trial was performed to evaluate safety, tolerability, recommended phase II dose (RD) and early signs of activity of L19-IL2.

Patients and methods: Five cohorts of patients with progressive solid tumours (n=21) received an intravenous infusion of L19-IL2 (from 5 to 30 Mio IU IL2 equivalent dose) on days 1, 3 and 5 every 3 weeks. This treatment cycle was repeated up to six times. In the following expansion phase, patients with metastatic renal cell carcinoma (RCC) (n=12) were treated at the RD of L19-IL2. Clinical data and laboratory findings were analysed for safety, tolerability and activity.

Results: Preclinical studies in rats and monkeys did not raise any safety concerns. The RD was defined to be 22.5 Mio IU IL2 equivalent. Pharmacokinetics of L19-IL2 was dose proportional over the tested range, with a terminal half-life of 2-3h. Toxicities were manageable and reversible with no treatment-related deaths. We observed stable disease in 17/33 patients (51%) and 15/18 with mRCC (83%) after two cycles. Median progression-free survival of RCC patients in the expansion phase of the study was 8 months (1.5-30.5).

Conclusions: L19-IL2 can be safely and repeatedly administered at the RD of 22.5 Mio IU IL2 equivalent in advanced solid tumours. Preliminary evaluation suggests clinical activity of L19-IL2 in patients with mRCC.

Trial registration: NCT01058538.

Publication types

  • Clinical Trial, Phase I
  • Clinical Trial, Phase II
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Animals
  • Antibodies, Neoplasm / blood
  • Antineoplastic Agents / administration & dosage*
  • Antineoplastic Agents / adverse effects
  • Antineoplastic Agents / pharmacokinetics
  • Area Under Curve
  • Carcinoma, Renal Cell / drug therapy*
  • Female
  • Humans
  • Infusions, Intravenous
  • Kidney Neoplasms / drug therapy*
  • Macaca fascicularis
  • Male
  • Middle Aged
  • Oncogene Proteins, Fusion / immunology
  • Rats
  • Rats, Sprague-Dawley
  • Recombinant Fusion Proteins / administration & dosage*
  • Recombinant Fusion Proteins / adverse effects
  • Recombinant Fusion Proteins / pharmacokinetics
  • Tomography, X-Ray Computed


  • Antibodies, Neoplasm
  • Antineoplastic Agents
  • L19-IL2 immunocytokine
  • Oncogene Proteins, Fusion
  • Recombinant Fusion Proteins

Associated data