A Combined Cyto- and Histopathological Diagnostic Approach Reduces Time to Diagnosis and Time to Therapy in First Manifestation of Metastatic Spinal Disease: A Cohort Study.

Malignant spinal lesions (MSLs) are frequently the first manifestation of malignant disease. Spinal care, diagnostic evaluation, and the initiation of systemic therapy are crucial for outcomes in patients (pts) with advanced cancer. However, histopathology (HP) may be time consuming. The additional evaluation of spinal lesions using cytopathology (CP) has the potential to reduce the time to diagnosis (TTD) and time to therapy (TTT). CP and HP specimens from spinal lesions were evaluated in parallel in 61 pts (CP/HP group). Furthermore, 139 pts in whom only HP was performed were analyzed (HP group). We analyzed the TTD of CP and HP within the CP/HP group. Furthermore, we compared the TTD and TTT between the groups. The mean TTD in CP was 1.7 ± 1.7 days (d) and 8.4 ± 3.6 d in HP (p < 0.001). In 13 pts in the CP/HP group (24.1%), specific therapy was initiated based on the CP findings in combination with imaging and biomarker results before completion of HP. The mean TTT in the CP/HP group was 21.0 ± 15.8 d and was significantly shorter compared to the HP group (28.6 ± 23.3 d) (p = 0.034). Concurrent CP for MSLs significantly reduces the TTD and TTT. As a result, incorporating concurrent CP for analyzing spinal lesions suspected of malignancy might have the potential to enhance pts' quality of life and prognosis in advanced cancer. Therefore, we recommend implementing CP as a standard procedure for the evaluation of MSLs.

Surgical Site Cytology to Diagnose Spinal Lesions.

Patients with new-onset malignant spinal lesions often have an urgent need for local spine intervention and systemic therapy. For optimal management, it is crucial to diagnose the underlying disease as quickly and reliably as possible. The aim of our current study was to determine the feasibility, sensitivity, specificity, and diagnostic certainty of complementary cytological evaluation of spinal lesions suspected of malignancy. In 44 patients, we performed histopathological biopsies and in parallel cytologic preparations from the malignant site. Cytological smears were prepared and stained for May-Grunwald and Giemsa. Bone biopsies were histopathologically analyzed according to the existing standard-of-care practices. In 42 of 44 cases (95%), a cytological sample was successfully obtained. In 40 cases (95.2%, Cohen's kappa: 0.77), the cytological diagnosis agreed with the histological diagnosis regarding the identification of a malignant lesion. This resulted in a sensitivity of 97% and a specificity of 80% as well as a diagnostic safety of 95%. Cytological analysis in the context of spinal surgery proved sufficient to establish a diagnosis of malignancy or its exclusion, expanding the existing diagnostic spectrum. Furthermore, implementation of this process as a routine clinical diagnostic might shorten the time to diagnosis and improve the treatment of this vulnerable patient group.

Fulminant blast crisis with de novo 11q23 rearrangement in a Philadelphia-positive CML patient undergoing treatment with dasatinib.

BACKGROUND: Progression of chronic myeloid leukemia (CML) is frequently accompanied by cytogenetic evolution, with an extra copy of the Philadelphia chromosome, trisomy 8 and 19, and isochromosome (17p) commonly detected. Translocations involving 11q23 chromosomal region have been rarely reported in CML. The few reported patients with blast crisis (BC) of CML carrying an 11q rearrangement have insufficient responses to tyrosine kinase inhibitors (TKIs) and possess a poor prognosis. CASE REPORT: We report the case of a 30-year-old man with CML who had a fulminant myeloid BC 4 months after initiation of first-line therapy with the TKI dasatinib, despite showing an optimal response at the 3-month timepoint. Despite cytoreductive therapy with hydroxyurea and 3rd-generation TKI ponatinib, the patient died within 10 days after the diagnosis of BC. Cytogenetic analyses revealed additional genetic aberrations including trisomy 8 and t(9;11)(p21;q23) involving the mixed lineage leukemia (MLL) gene. CONCLUSION: The presence of 11q23 rearrangements in the relapse clone in BC of CML most likely accounts for the adverse clinical outcome. Thus, in the case of rapid and unexpected BC, the presence of 11q rearrangements should be tested together with other additional chromosomal alterations, and immediate addition of chemotherapy to the TKIs should be evaluated.

Deep sequencing of bone marrow microenvironments of patients with del(5q) myelodysplastic syndrome reveals imprints of antigenic selection as well as generation of novel T-cell clusters as a response pattern to lenalidomide.

In myelodysplastic syndromes with a partial deletion of the long arm of chromosome 5, del(5q), lenalidomide is believed to reverse anergic T-cell immunity in the bone marrow resulting in suppression of the del(5q) clone. In this study we used next-generation sequencing of immunoglobulin heavy chain (IGH) and T-cell receptor beta (TRB) rearrangements in bone marrow-residing and peripheral blood-circulating lymphocytes of patients with del(5q) myelodysplastic syndromes to assess the immune architecture and track adaptive immune responses during treatment with lenalidomide. The baseline bone marrow B-cell space in patients was comparable to that of age-matched healthy controls in terms of gene usage and IGH clonality, but showed a higher percentage of hypermutated IGH sequences, indicating an expanded number of antigen-experienced B lineage cells. Bone marrow B lineage clonality decreased significantly and hypermutated IGH clones normalized upon lenalidomide treatment, well in line with the proliferative effect on healthy antigen-inexperienced B-cell precursors previously described for this drug. The T-cell space in bone marrow of patients with del(5q) myelodysplastic syndromes showed higher TRB clonality compared to that of healthy controls. Upon lenalidomide treatment, myelodysplastic syndrome-specific T-cell clusters with low to medium spontaneous generation probabilities emerged; these clusters were shared across patients, indicating a common antigen-driven T-cell response pattern. Hence, we observed B lineage diversification and generation of new, antigen-dependent T-cell clusters, compatible with a model of adaptive immunity induced against the del(5q) clone by lenalidomide. Overall, this supports the concept that lenalidomide not only alters the functional T-cell state, but also the composition of the T- and B-cell repertoires in del(5q) myelodysplastic syndromes.

T-cell diversification reflects antigen selection in the blood of patients on immune checkpoint inhibition and may be exploited as liquid biopsy biomarker.

Cancer immunotherapy with antibodies targeting immune checkpoints, such as programmed cell death protein 1 (PD-1), shows encouraging results, but reliable biomarkers predicting response to this costly and potentially toxic treatment approach are still lacking. To explore an immune signature predictive for response, we performed liquid biopsy immunoprofiling in 18 cancer patients undergoing PD-1 inhibition before and shortly after initiation of treatment by multicolor flow cytometry and next-generation T- and B-cell immunosequencing (TCRß/IGH). Findings were correlated with clinical outcomes. We found almost complete saturation of surface PD-1 on all T-cell subsets after the first dose of the antibody. Both T- and B-cell compartments quantitatively expanded during treatment. These expansions were mainly driven by an increase in the activated T-cell compartments, as well as of naïve B- and plasma cells. Deep immunosequencing revealed a clear diversification pattern of the clonal T-cell space indicative of antigenic selection in 47% of patients, while the remaining patients showed stable repertoires. 43% of the patients with a diversification pattern showed disease control in response to the PD-1 inhibitor. No disease stabilizations were observed without clonal T-cell space diversification. Our data show for the first time a clear impact of PD-1 targeting not only on circulating T-cells, but also on B-lineage cells, shedding light on the complexity of the anti-tumor immune response. Liquid biopsy T-cell next-generation immunosequencing should be prospectively evaluated as part of a composite response prediction biomarker panel in the context of clinical studies.

Immunomodulatory effects of sorafenib on peripheral immune effector cells in metastatic renal cell carcinoma.

BACKGROUND: Tyrosine kinase inhibitors (TKI) such as sorafenib have substantially improved the prognosis of metastatic renal cell carcinoma (mRCC) patients, but long-term remissions have only been reached with immunotherapy. Sequencing or combining TKI treatment with immunotherapy may represent an attractive therapeutic concept. However, in vitro data have shown that TKI may not only affect tumour cells, but also inhibit signalling in immune effector cells. Therefore, we asked whether sorafenib had an influence on peripheral immune effector cells in a cohort of 35 mRCC patients receiving sorafenib treatment. METHODS: Peripheral blood (pB) samples were analysed at baseline and after 8 weeks of treatment. IL-10 and TGF-ß mRNA levels were quantified by RT-PCR; regulatory T cell (Treg) counts and intracellular cytokine responses (TNF-α, IFN-γ, IL-10 and TGF-ß) of mononuclear cell subsets were determined by flow cytometry after in vitro stimulation with PMA/ionomycin. RESULTS: Sorafenib did not alter the elevated TGF-ß and IL-10 mRNA levels or elevated frequencies of IL-10 and TGF-ß producing monocytes and had no influence on type 1 cytokine responses in pB. CD4+CD25(high) FOXP3+/CD3+ T cells, likely representing Treg cells, decreased during sorafenib therapy. CONCLUSIONS: In vivo, sorafenib treatment was associated with a decrease in frequency of Treg cells without influencing the function of peripheral immune effector cells. Therefore, although sorafenib did not convert the immunosuppressive phenotype associated with mRCC, it seemed to be a possible candidate for combination with immunotherapy.

Identification of an immunogenic HLA-A*0201-binding T-cell epitope of the transcription factor PAX2.

PAX2 is a transcription factor and member of the highly conserved family of paired box genes. PAX2 is aberrantly expressed in a variety of solid and hematologic malignancies. PAX2 regulates the transcription factor Wilms tumor gene 1, which is a promising target of cancer immunotherapy. The aim of this study was to apply a modified reverse immunology strategy to identify immunogenic epitopes of PAX2 which could be useful for cancer immunotherapy. Thirteen potential HLA-A*0201 epitopes were predicted by a major histocompatibility complex binding algorithm (SYFPEITHI) and a proteasome cleavage algorithm (PAProC) and screened for recognition by T cells from HLA-A*02-positive cancer patients using intracellular cytokine cytometry. Epitope-specific T cells were generated from CD4CD25 regulatory T-cell-depleted peripheral blood mononuclear cell. Nine of 20 colorectal cancer patients, 1 of 13 renal cell carcinoma patients, and 2 of 17 lymphoma patients had a spontaneous CD8 T-cell response toward at least 1 of 6 PAX2 peptide pools. None of the 20 healthy subjects showed reactivity toward PAX2. PAX2.337-345 (TLPGYPPHV)-specific T cells could repeatedly be generated, which specifically lysed the PAX2 expressing colorectal tumor cell line SW480. In this study, a modified reverse immunology strategy was employed to identify a first immunogenic HLA-A*0201 restricted T-cell epitope and natural ligand of the tumor antigen PAX2. Thus, PAX2 is another embryonic transcription factor, which is of potential interest as immunotherapy target antigen.

Vaccination strategies in patients with renal cell carcinoma.

Although new treatment options for patients with advanced renal cell cancer (RCC) have been developed within recent years, vaccination is still a promising emerging treatment option. An increasing number of tumor-associated antigens (TAA) available for RCC are currently used and analyzed for their efficacy for antigen-specific vaccine strategies. Recently, antigen-specific vaccination with dendritic cells in patients with metastatic RCC was shown to induce cytotoxic T cell response associated with objective clinical responses in some of the patients. Furthermore, current studies focus on the development of more effective vaccine regimes, such as the application of polyvalent, HLA-independent RNA coding for multiple TAA and adjuvants. First results demonstrate promising clinical and immunological efficacy. The efficacy of antigen-specific vaccination might be improved by a combination of tyrosine kinase inhibitors, since sunitinib was shown to promote T cell induction following vaccination in a mouse model and elimination of regulatory T cells.

A clinical and immunologic phase 2 trial of Wilms tumor gene product 1 (WT1) peptide vaccination in patients with AML and MDS.

This study investigated the immunogenicity of Wilms tumor gene product 1 (WT1)-peptide vaccination in WT1-expressing acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS) patients without curative treatment option. Vaccination consisted of granulocyte-macrophage colony-stimulating factor subcutaneously days 1 to 4, and WT1.126-134 peptide and 1 mg keyhole limpet hemocyanin on day 3. The initial 9 patients received 4 vaccinations biweekly, then monthly, and the subsequent 10 patients received continual biweekly vaccination. Seventeen AML patients and 2 refractory anemia with excess blasts patients received a median of 11 vaccinations. Treatment was well tolerated. Objective responses in AML patients were 10 stable diseases (SDs) including 4 SDs with more than 50% blast reduction and 2 with hematologic improvement. An additional 4 patients had clinical benefit after initial progression, including 1 complete remission and 3 SDs. WT1 mRNA levels decreased at least 3-fold from baseline in 35% of patients. In 8 of 18 patients, WT1-tetramer(+) T cells increased in blood and in 8 of 17 patients in bone marrow, with a median frequency in bone marrow of 0.18% at baseline and 0.41% in week 18. This WT1 vaccination study provides immunologic, molecular, and preliminary evidence of potential clinical efficacy in AML patients, warranting further investigations.

Sunitinib treatment for patients with advanced clear-cell renal-cell carcinoma after progression on sorafenib.

BACKGROUND: Sorafenib and sunitinib are tyrosine kinase inhibitors with largely overlapping specificities, approved for the treatment of metastatic renal-cell carcinoma (RCC). It was unclear whether the similarities of the two drugs would lead to complete cross-resistance, or whether sequential application would be efficacious. METHODS: Patients with metastatic RCC and progression on sorafenib treatment were treated with repeated cycles of sunitinib, 50 mg for 4 weeks, followed by a 2-week break. Response (Response Evaluation Criteria in Solid Tumors, RECIST) was assessed every second cycle. RESULTS: A total of 22 patients with progression on sorafenib were accrued. Initially, sorafenib treatment was efficacious in all patients, with 7 showing partial response (PR) and 15 stable disease (SD), and subsequent disease progression. With 4 PRs (18%) and 12 SD (55%) a disease control rate of 73% was achieved. The median progression-free survival (PFS) on sunitinib was 21.5 weeks; median overall survival (OS) was not reached. Estimated 1-year PFS and OS were 31 and 60%, respectively. There was no apparent relationship between response to sorafenib and outcome on sunitinib. CONCLUSION: In our cohort of patients with RCC and progression after initial efficacy of sorafenib, the efficacy data of second-line sunitinib were close to published results of first-line treatment, suggesting limited clinically relevant cross-resistance.

CMV-specific central memory T cells reside in bone marrow.

CMV-specific CD8(+) T cell responses in peripheral blood (PB) are characterized by a preponderance of effector and effector memory T cells. CMV-specific central memory T cells (T(CM)), which are considered crucial in maintaining long-term immunity, are rarely detectable in PB. In this study we have analyzed differentiation and function of CMV pp65-specific CD8(+) T cells in paired samples of human PB and BM using intracellular cytokine and tetramer staining. Overall frequencies of CMV pp65-specific T cells were similar in PB compared to BM; however, CMV-specific CD45RA(-)CCR7(+) T(CM) were almost exclusively detectable in BM, which was not related to a general accumulation of T(CM) in BM. In vitro, CMV-specific T cells could be more efficiently expanded from BM (median 128-fold, n=6) than from PB (median 72-fold, p=0.01). Taken together, these data show that the BM is a compartment harboring CMV-specific T(CM) and underline the concept of the BM as a secondary immune organ. CMV specific BM-derived T(CM) might be a valuable source for generating T cells for adoptive transfer.

Addition of GM-CSF to a peptide/KLH vaccine results in increased frequencies of CXCR3-expressing KLH-specific T cells.

T-cell trafficking is determined by expression patterns of chemokine receptors. The chemokine receptor CXCR3 is expressed on a subpopulation of type 1 T cells and plays an important role for migration of T cells into inflamed and tumor tissues. Here, we studied the chemokine receptor expression on specific T cells generated against the neoantigen keyhole limpet hemocyanin (KLH) in patients who had been immunized in the context of a tumor peptide vaccination trial with or without the adjuvant granulocyte-macrophage colony-stimulating factor (GM-CSF). In patients immunized in the presence of GM-CSF the fraction of CXCR3(+) KLH-specific T cells was significantly higher than in patients immunized in the absence of GM-CSF (median 45 vs. 20%, P = 0.001). In contrast, the chemokine receptor CCR4, associated with migration to the skin was found in both cohorts on less than 10% of KLH-specific T cells. These results show that CXCR3 expression on vaccine-induced T cells can be modulated by modifying the local vaccine milieu.

Identification of a highly immunogenic HLA-A*01-binding T cell epitope of WT1.

PURPOSE: The transcription factor Wilms tumor protein 1 (WT1) belongs to a new generation of tumor antigens, as it is essential for tumor cell proliferation and is highly expressed in various hematologic and solid malignancies. The aim of this study was to apply a modified reverse immunology strategy to identify immunogenic epitopes of WT1 which could be useful for immunotherapy. EXPERIMENTAL DESIGN: Potential HLA-A*01 epitopes predicted by a MHC binding algorithm were screened for recognition by peripheral blood mononuclear cells (PBMC) from patients with spontaneous T cell responses using intracellular cytokine cytometry. Epitope processing was shown by proteasomal cleavage. Epitope-specific T cells were generated from CD4+CD25+ regulatory T cell-depleted PBMC. RESULTS: One of five predicted HLA-A*01-binding candidate epitopes showed high immunogenicity as 5 of 14 patients with hematologic malignancies had WT1.317-327-reactive T cells ranging from 0.4% to 1.5% of CD3+CD8+ T cells. Proteasomal degradation assays indicated the cleavage of WT1.317-327. The depletion of regulatory T cells from PBMCs enabled the rapid expansion of WT1.317-327-specific CTL, whereas no CTL could be generated from unfractionated PBMC. WT1.317-327-specific CTL efficiently lysed an autologous WT1-expressing tumor cell line but not HLA-A*01-negative WT1-expressing tumor cells. Immunogenicity of the epitope across histologies was verified by the demonstration of spontaneous ex vivo WT1.317-327-specific T cell responses in two of six patients with HLA-A*01-positive melanoma or lung cancer. CONCLUSION: In this study, a modified reverse immunology strategy was employed to identify a first immunogenic HLA-A*01-restricted T cell epitope of the tumor antigen WT1, which is of considerable interest for use in vaccination trials.

Cross-presentation of HLA class I epitopes from influenza matrix protein produced in Saccharomyces cerevisiae.

Here we report that genetically engineered yeast of the strain Saccharomyces cerevisiae expressing full-length influenza matrix protein (IMP) attached to the yeast cell wall are a very versatile host for antigen delivery. Feeding of dendritic cells with either intact yeast expressing IMP protein or soluble IMP protein cleaved off the cell wall resulted in protein uptake, processing and cross-presentation of IMP-derived peptides. This process was analysed using previously established T-cell lines recognizing the immuno-dominant 58-66 peptide when presented by HLA-A2*0201 complexes. In addition, IMP(58-66)/HLA-A2*0201-specific antibodies were selected from a naive phage library which confirmed that peptide presentation was an active process of endocellular uptake and not just a result of external peptide loading. Moreover, MHC peptide antibodies could block the recognition of peptide-presenting dendritic cells by IMP(58-66)-specific T-cells in a dose dependent manner. There was no difference in T-cell recognition when either intact yeast or yeast cell extracts were used for DC feeding. Together, these data demonstrate that yeast derived proteins either in their soluble form or as part of a whole yeast vaccine are taken up, processed and presented by dendritic cells in HLA class I context.

Specific central memory T cells in the bone marrow of patients immunized against tyrosinase peptides.

The goal of vaccination against tumors is the induction of effector T cells mediating tumor destruction and memory T cells providing long-term immunity. Several previous studies in patients vaccinated with major histocompatibility complex (MHC) class I peptides failed to show induction of central memory T cells, which are considered important to provide long-term memory. This study examined the subset composition and function of specific T cells generated by immunization with MHC class I binding tyrosinase peptides in combination with the adjuvants granulocyte-macrophage colony-stimulating factor and keyhole limpet hemocyanin in peripheral blood (PB) and bone marrow (BM) of melanoma patients. Most of the tyrosinase-specific T cells in PB had a CD45RA(+)CCR7(-) effector phenotype. In contrast to this, a large subset of tyrosinase-specific T cells in BM were memory T cells, including CD45RA(+)CCR7(-) central and CD45RA(-)CCR7(-) effector memory T cells. BM tyrosinase-specific T cells were functional, because they produced interferon-gamma and had a high proliferative potential. This study suggests that peptide vaccination can generate a fully functional memory T-cell response characterized by central and effector memory phenotypes, proliferative potential, and BM tropism.