Phase I Study of Muscadine Grape Extract for Patients With Advanced Cancer

OBJECTIVE

Preclinical studies with muscadine grape extract (MGE) show antitumor activity and decreased systemic inflammation. This phase I study (NCT02583269) assessed safety and tolerability of a proprietary MGE preparation in patients with advanced solid tumors.

METHODS

Patients with metastatic or unresectable cancers who were progressing on standard therapies were assigned to MGE in a standard 3+3 design. Five dose levels were tested (320 to 1600 mg total phenolics/d). Safety and maximum-tolerated dose were assessed after 4 weeks. Patients were evaluated for response at 8 weeks and continued on MGE if clinically stable. Secondary outcomes were response, survival, adherence, fatigue, and quality of life (QOL).

RESULTS

In total, 23 patients (lung, n=7; gastrointestinal, n=7; genitourinary, n=6; other, n=3) received MGE capsules by mouth twice daily. The cohort [median age 72 years, 48% Eastern Cooperative Oncology Group (ECOG) 2] was heavily pretreated. After 4 weeks on MGE, possibly attributable adverse events grade 2 or higher were fatigue (n=1), decreased lymphocyte count (n=1), and constipation (n=2), including 1 dose-limiting toxicity for grade 3 constipation. Maximum-tolerated dose was not reached. No partial responses were observed. Median time on therapy was 8 weeks, with 29% of patients treated beyond 16 weeks and a median overall survival of 7.2 months. QOL and fatigue levels were stable from baseline to 8 weeks. Higher MGE dose was correlated with improvement in self-reported physical well-being QOL at 8 weeks (r=0.6; P=0.04).

CONCLUSIONS

MGE is safe and well-tolerated in heavily pretreated and older cancer patients.  The potential anticancer properties and the effects of MGE on physical well-being and QOL metrics will be evaluated in future studies.

Unbiased Screens Show CD8+ T Cells of COVID-19 Patients Recognize Shared Epitopes in SARS-CoV-2 that Largely Reside outside the Spike Protein

Developing effective strategies to prevent or treat coronavirus disease 2019 (COVID-19) requires understanding the natural immune response to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). We used an unbiased, genome-wide screening technology to determine the precise peptide sequences in SARS-CoV-2 that are recognized by the memory CD8+ T cells of COVID-19 patients. In total, we identified 3-8 epitopes for each of the 6 most prevalent human leukocyte antigen (HLA) types. These epitopes were broadly shared across patients and located in regions of the virus that are not subject to mutational variation. Notably, only 3 of the 29 shared epitopes were located in the spike protein, whereas most epitopes were located in ORF1ab or the nucleocapsid protein. We also found that CD8+ T cells generally do not cross-react with epitopes in the four seasonal coronaviruses that cause the common cold. Overall, these findings can inform development of next-generation vaccines that better recapitulate natural CD8+ T cell immunity to SARS-CoV-2.

A Phase III open-label trial to evaluate efficacy and safety of CPI-613 plus modified FOLFIRINOX (mFFX) versus FOLFIRINOX (FFX) in patients with metastatic adenocarcinoma of the pancreas

Devimistat (CPI-613®) is a novel lipoate analog that inhibits the tricarboxcylic acid cycle at two key carbon entry points. Through its inhibition of pyruvate dehydrogenase and a-ketoglutarate dehydrogenase complexes, devimistat inhibits the entry of glucose and glutamine derived carbons, respectively. Pancreatic cancer is dependent on mitochondrial function for enhanced survival and aggressiveness. In a Phase I study of modified FOLFIRINOX, in combination with devimistat for metastatic pancreatic cancer patients, there was a 61% objective response rate including a 17% complete response rate. This report outlines the rationale and design of the AVENGER 500 study, a Phase III clinical trial of devimistat in combination with modified FOLFIRINOX compared with FOLFIRINOX alone for patients with previously untreated metastatic adenocarcinoma of the pancreas. Clinical trial registration: NCT03504423.

Circulating mutational portrait of cancer: manifestation of aggressive clonal events in both early and late stages

BACKGROUND

Solid tumors residing in tissues and organs leave footprints in circulation through circulating tumor cells (CTCs) and circulating tumor DNAs (ctDNA). Characterization of the ctDNA portraits and comparison with tumor DNA mutational portraits may reveal clinically actionable information on solid tumors that is traditionally achieved through more invasive approaches.

METHODS

We isolated ctDNAs from plasma of patients of 103 lung cancer and 74 other solid tumors of different tissue origins. Deep sequencing using the Guardant360 test was performed to identify mutations in 73 clinically actionable genes, and the results were associated with clinical characteristics of the patient. The mutation profiles of 37 lung cancer cases with paired ctDNA and tumor genomic DNA sequencing were used to evaluate clonal representation of tumor in circulation. Five lung cancer cases with longitudinal ctDNA sampling were monitored for cancer progression or response to treatments.

RESULTS

Mutations in TP53, EGFR, and KRAS genes are most prevalent in our cohort. Mutation rates of ctDNA are similar in early (I and II) and late stage (III and IV) cancers. Mutation in DNA repair genes BRCA1, BRCA2, and ATM are found in 18.1% (32/177) of cases. Patients with higher mutation rates had significantly higher mortality rates. Lung cancer of never smokers exhibited significantly higher ctDNA mutation rates as well as higher EGFR and ERBB2 mutations than ever smokers. Comparative analysis of ctDNA and tumor DNA mutation data from the same patients showed that key driver mutations could be detected in plasma even when they were present at a minor clonal population in the tumor. Mutations of key genes found in the tumor tissue could remain in circulation even after frontline radiotherapy and chemotherapy suggesting these mutations represented resistance mechanisms. Longitudinal sampling of five lung cancer cases showed distinct changes in ctDNA mutation portraits that are consistent with cancer progression or response to EGFR drug treatment.

CONCLUSIONS

This study demonstrates that ctDNA mutation rates in the key tumor-associated genes are clinical parameters relevant to smoking status and mortality. Mutations in ctDNA may serve as an early detection tool for cancer. This study quantitatively confirms the hypothesis that ctDNAs in circulation is the result of dissemination of aggressive tumor clones and survival of resistant clones. This study supports the use of ctDNA profiling as a less-invasive approach to monitor cancer progression and selection of appropriate drugs during cancer evolution.

Abstract P6-05-05: Gene expression signatures of effector immune cell abundance are significantly associated with pathologic breast tumor response in the neoadjuvant setting

Background

Neoadjuvant chemotherapy for early breast cancer leads to significant clinical response rates of 70-90%, with only 10-20% complete pathologic responses (pCR). The biological and clinical factors that determine the degree of pCR are incompletely understood and most investigated are drug choice, proliferation index, intrinsic subtypes and host-therapy interactions. Mounting evidence indicates that the patient's immune system contributes to tumor regression and can be modulated by therapies. Investigations using immunohistochemical approaches confirmed that immune cell infiltrate on pre-treatment or post-treatment tumor biopsies are associated with greater frequency of pCR. The cell types most frequently observed with this association are effector tumor infiltrating lymphocytes (TILs) such as cytotoxic T cells, natural killer cells and B cells suggesting a strong link between infiltrating immune cell abundance and anti-tumor immunogenicity. More recently, we and others have shown that the relative abundance of TIL in breast cancer can be quantified by intratumoral transcript levels of coordinately expressed, immune cell-specific genes. Through expression microarray analysis, we recently discovered three separate immune gene signatures, or metagenes, that appear to reflect the relative abundance of distinct tumor-infiltrating leukocyte populations. These metagenes, referred as the B/P (B-cell/Plasma cell), T/NK (T-cell/Natural Killer cell) and M/D (Monocyte/Dendritic cell) immune metagenes, were significantly associated with the distant metastasis-free survival of patients with highly proliferative cancer of the Basal-like, HER2-Enriched and Luminal B subtypes, in particular.

Aim

Given the histopathological evidence that TIL abundance is predictive of neoadjuvant treatment efficacy, we evaluated the therapy-predictive potential of the prognostic immune metagenes. We hypothesized that the pre-chemotherapy immune gene signatures would be significantly predictive of tumor responses.

Methods

In a multi-institutional, meta-cohort analysis of 701 breast tumor patients receiving neoadjuvant chemotherapy, gene expression profiles of tumor biopsies were investigated to determine the relationships between immune metagenes, tumor proliferative capacity, and molecular breast tumor subtypes.

Results

We used multiple logistic regression to investigate the predictive value of the immune signatures. In a univariate analysis the B/P, T/NK and M/D immune metagenes were statistically significantly associated with excellent pathologic response as defined by residual cancer burden scores ((B/P (odds ratio (95% CI) 1.6 (1.3, 1.9), T/NK 1.6 (1.2, 2.0), M/D 1.7 (1.3, 2.1)). In multivariate analysis, B/P and M/D metagenes remained significant after adjustment for intrinsic subtype and proliferation (B/P 1.25 (1.01, 1.54), M/D 1.4 (1.03, 1.90).

Conclusions

Gene expression signatures of infiltrating immune cells carry both prognostic and therapy-predictive value. Furthermore, our work highlights a less described role for myeloid derived antigen presenting cells that could explain the variability of pathologic response to neoadjuvant chemotherapy.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P6-05-05.