Abstract OT2-06-01: Highly innovative personalized RNA-immunotherapy for patients with triple negative breast cancer

Background: The treatment of triple negative breast cancer (TNBC) is hampered by the lack of established therapeutic targets such as hormone receptors or HER-2. Chemotherapy and radiotherapy is the standard of care, yet survival rates in TNBC remain poor. Approaches tailored to the patient's individual tumor signature may lead to improved therapeutic outcome. We have set up a clinical workflow covering drug development (from target discovery to manufacturing) and drug release providing a custom-made investigational medicinal product (IMP) for each individual patient.

Trial Design: A phase I/II trial assesses the feasibility, safety and biological efficacy of this personalized immunotherapy in three clinical sites in Germany and Sweden. TNBC patients (pT1cN0M0 – TxNxM0) after completion of initial standard of care therapy will be allocated to one of two study arms. Patients in ARM1 receive 8 vaccination cycles with a personalized combination of shared tumor-associated antigens, selected based on each patient tumor's antigen-expression profile out of a WAREHOUSE of pre-manufactured mRNA vaccine. Patients in ARM2 receive the personalized mRNA WAREHOUSE vaccine followed by 8 vaccination cycles of an on-demand manufactured mRNA MUTANOME vaccine encoding up to twenty unique neo-epitopes of the individual patient identified by next generation sequencing. The mRNAs are administered intravenously as a nanoparticulate lipoplex formulation, which protects RNA from degradation, activates innate immunity, transfects APCs and consequently induces highly potent antigen-specific T-cell responses. The treatment of 12 patients in ARM1 is completed and enrolment of patients for ARM2 has started. Preliminary data show that the RNA-WAREHOUSE approach is feasible and can be applied safely. Biomarker analysis is ongoing. This approach is promising as it addresses the heterogeneity of TNBC.

The TNBC-MERIT trial was initially funded by the EU Commission's FP7 and led by BioNTech AG.

Citation Format: Schmidt M, Bolte S, Frenzel K, Heesen L, Derhovanessian E, Bukur V, Diken M, Gruetzner J, Kreiter S, Klein A, Kuhn A, Langer D, Loewer M, Lindman H, Schneeweiss A, Tuereci O, Sahin U. Highly innovative personalized RNA-immunotherapy for patients with triple negative breast cancer [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr OT2-06-01.

The influence of different illumination parameters on protoporphyrin IX induced cell death in squamous cell carcinoma cells

BACKGROUND

Topical photodynamic therapy (PDT) is a highly effective therapy especially for extended cancerized fields of the skin. Whenever extended fields are treated pain management is advisable. Light source mediated pain management can be performed by reducing fluence rates, as long as this does not compromise efficacy.

METHODS

Two squamous cell carcinoma cell lines (A431 and SCC-13) were subjected to in vitro PDT using two different ALA concentrations and synthesis intervals and protoporphyrin IX (PpIX) synthesis was assessed. Two total light doses (6 J/cm² and 37 J/cm²) were applied at three different fluence rates and cell viability was measured using the MTS-test.

RESULTS

Both cell lines synthetized PpIX at different kinetics. A431 cells produced a maximum 28.6 nmol/l PpIX, while SCC-13 reached only a production of 8.7 nmol/l. Illumination reduced cell viability depending on PpIX content and light dose. When a lower light dose (6 J/cm²) was applied, only the combination with the highest PpIX content was effective in A431 cells and no effect could be detected in SCC-13 cells. With a light dose of 37 J/cm², lower PpIX amounts became effective in A431 and cell death could be induced in SCC-13 cells. Light fluence rate had no differential effect in this setup.

CONCLUSIONS

In both, A431 and SCC-13 cells, total light dose is a key factor for photodynamic efficacy. Additionally, our results hint towards a threshold concentration of PpIX upon which a drastic loss of viability occurs. Light fluence rate in the analyzed range is not a limiting factor of photodynamic cytotoxicity. This may allow for the clinical implementation of low fluence rate protocols for pain management without compromising efficacy.