Iovance Biotherapeutics Inc (IOVA)

[jondoeuk]

ESMO abstracts

1) 1053P - Iovance generation-2 tumour-infiltrating lymphocyte (TIL) product is reinvigorated during the manufacturing process

Background
Adoptive cell therapy is a therapeutic strategy that may reverse dysfunction in endogenous TIL, through a process that involves emigration of T cells out of the immunosuppressive TME, significantly expanding the TIL ex vivo while reinvigorating them, and re-infusing the cells into the patient. To determine whether TIL generated using Iovance’s Gen 2 expansion protocol (D22 TIL) resulted in a reinvigorated TIL population, relative to endogenous TIL (D0), D0 and D22 TIL were assessed for phenotype, function and tumor reactivity.

Methods
Endogenous CD3+ TIL (D0), isolated from digested tumor biopsies, were sorted using FACS and compared to TIL expanded for 22 days using Iovance’s Gen 2 process (D22). T cell subsets from 7 paired D0 and D22 TIL from melanoma, cervical cancer, and head and neck squamous cell carcinoma were assessed for phenotypic and regulatory markers by FACS, function by in vitro activation, and tumor reactivity by autologous tumor co-culture.

Results
At D22 terminally differentiated T cells remained below D0 levels. D22 TIL upregulated markers associated with activation. Treg were mostly absent from D22 TIL. Furthermore, at D22, the CD8:CD4 ratio increased relative to D0, indicating preferential proliferation of CD8+ cells during. The main effector memory T cell (TEM) subset was enriched, suggesting a stem cell memory and central memory to TEM transition. The canonical exhaustion marker PD-1 decreased significantly at D22. Expansion of sorted PD-1+ cells suggested downregulated expression rather than T cell elimination. In all sample pairs, TCR induction of IFNg was dramatically enhanced at D22 vs D0. Finally, D22 TIL displayed greater specific in vitro tumor cytotoxicity than endogenous TIL.

Conclusions
Our results suggest that the ex vivo expansion of TIL, using Iovance’s Generation 2 process, reverses the dysfunctional state of the T cells from the tumor microenvironment, by transitioning their phenotypic, functional and tumor-reactive profile, thereby rendering the cells reinvigorated and capable of producing a potent and effective anti-tumor response in vivo.

2) 873P - In vivo persistence of Iovance tumour-infiltrating lymphocytes LN-145 in cervical cancer patients

Background
LN-145, an ex vivo expanded autologous TIL product, demonstrates efficacy in patients with advanced cervical cancer in study C-145-04, with 44% ORR and 85% DCR. Here, we characterized the clonal composition of LN-145 infusion products, the in vivo fate of TIL clones, and asked how they related to clinical response, persistence of TIL in patients, and HPV reactivity.

Methods
LN-145 TIL products from 27 patients were subjected to CDR3 RNA-seq to establish a repertoire that was then monitored in pre- and post-infusion PBMC for each patient. Known statistical methods were used to determine clonal diversity, overlap across samples, and correlations to clinical response and HPV reactivity as assessed by co-culturing with peptide-loaded autologous APC.

Results
Number of unique TIL clones and corresponding diversity indices averaged 25,222 [3,829-87,751] and 7.83 [4.7-11.4], respectively, and distributed along a head and tail curve with 10 most abundant clones representing ~42% of the total repertoires. Less than 1% of clones were detected in more than 3 of the 27 patients. TIL-derived clones persisted at all post-infusion timepoints. A mean of 2043 clones were shared at D42, representing 11% and 20% of LN-145 and PBMC clones, respectively, and a substantial portion of the total TIL (66%) and D42 (57%) repertoires. Clonal persistence did not predict the clinical response. No correlation was found between HPV reactivity and response. As many as 47% of the TIL products did not react to HPV.

Conclusions
LN-145 is a highly polyclonal and patient-specific product endowed with in vivo persistence ability. The uniqueness of each TIL product and observation of responses with HPV non-reactive TIL highlights the challenge of identifying a single TCR as a common mediator of activity and supports using LN-145 to treat solid tumors with their associated private neoantigen spectra.

3) 1052P - Genetic modification of Iovance’s TIL through TALEN-mediated knockout of PD-1 as a strategy to empower TIL therapy for cancer

Background
Iovance’s autologous tumor-infiltrating lymphocyte (TIL) product has reported efficacy results in metastatic melanoma and cervical cancer patients that reflect an ORR of 36.4% and 44%, respectively. While this appears superior to standard of care, we seek further improvements by creating a new generation of TIL. One potential limitation of TIL therapy is inactivation by the PD-1/PD-L1 pathway, which provides rationale for combining TIL with PD-1 blockade. Here, we abrogate PD-1 within the TIL product to reduce PD-L1-dependent TIL inactivation. Consequent TIL killing of cancer cells may be enhanced while avoiding the toxicity associated with systemic anti-PD-1 therapy, thereby consolidating two complementary benefits in one treatment. For this, we performed knockout (KO) of the PDCD1 gene in TIL, utilizing transcription activator-like effector nuclease (TALEN) technology.

Methods
TIL from breast, ovarian, and lung cancers were tested. TIL were electroporated with PD-1 TALEN mRNA and expanded in culture. PD-1 KO efficiency and phenotype were evaluated by flow cytometry. Effector function of PD-1 KO TIL was verified in cell-based assays.

Results
Delivery of TALEN mRNA to TIL by electroporation was highly efficient (> 90%) and did not compromise cell viability, indicating that the full spectrum of polyclonal and diverse TIL could be targeted. Up to 72% PD-1 KO efficiency was achieved. All PD-1 KO TIL were successfully expanded through a novel process. Levels of activation/exhaustion markers in PD-1 KO TIL were comparable to controls, arguing against any compensatory mechanisms in response to decreased PD-1 expression. Most importantly, PD-1 KO TIL were highly functional in all standard assays.

Conclusions
In this first report of TALEN-mediated gene editing of polyclonal TIL, a robust protocol was established for the generation of PD-1 KO polyclonal TIL exhibiting the features of a highly active therapeutic product. These results, along with the strong rationale supporting the combination of TIL with PD-1 inhibition, support clinical testing of this approach that may enhance the potency of immunotherapy while retaining all safety aspects of conventional TIL therapy.

https://cslide.ctimeetingtech.com/esmo2020/attendee/confcal_2/presentation/list?q=iovance