The gut microbiome has been shown to influence the response of tumors to anti–PD-1 (programmed cell death–1) immunotherapy in preclinical mouse models and observational patient cohorts. However, modulation of gut microbiota in cancer patients has not been investigated in clinical trials. In this study, we performed a phase 1 clinical trial to assess the safety and feasibility of fecal microbiota transplantation (FMT) and reinduction of anti–PD-1 immunotherapy in 10 patients with anti–PD-1–refractory metastatic melanoma. We observed clinical responses in three patients, including two partial responses and one complete response. Notably, treatment with FMT was associated with favorable changes in immune cell infiltrates and gene expression profiles in both the gut lamina propria and the tumor microenvironment. These early findings have implications for modulating the gut microbiota in cancer treatment.

Highlights d Bifidobacterium abundance increases in the gut during pregnancy in women and mice d Progesterone supplementation alters gut microbial composition in mice and in vitro d Progesterone supplementation increases Bifidobacterium abundance in mice and in vitro d We suggest that progesterone promotes Bifidobacterium growth during late pregnancy

Deletions detected in cytogenetic and loss of heterozygosity (LOH) studies indicate that at least one tumour suppressor gene maps to the long arm of chromosome 10. Previous deletion mapping studies have observed LOH on 10q in about 30% of melanomas analysed. The PTEN gene, mapping to chromosome band 10q23.3, encodes a protein with both lipid and protein phosphatase activity. Somatic mutations and deletions in have been detected in a variety of cell lines and tumours, including melanoma samples. We performed mutation analyses and extensive allelic loss studies to investigate the role this gene plays in melanoma pathogenesis. We found that a total of 34 out of 57 (60%) melanoma cell lines carried hemizygous deletions of chromosome 10q encompassing the PTEN locus. A further three cell lines carried smaller deletions excluding PTEN. Inactivation of both PTEN alleles by exon-specific homozygous deletion or mutation was observed in 13 out of 57 (23%) melanoma cell lines. The mutation spectrum observed does not indicate an important role for ultraviolet radiation in the genesis of these mutations, and evidence from three cell lines supports the acquisition of PTEN aberrations in culture. Ten out of 49 (20%) matched melanoma tumour/normal samples harboured hemizygous deletions of either the whole chromosome or most of the long arm. Mutations within were detected in only one of the 10 tumours demonstrating LOH at 10q23 that were analysed. These results suggest that PTEN inactivation may be important for the propagation of melanoma cells in culture, and that another chromosome 10 tumour suppressor gene may be important for melanoma pathogenesis.

Alzheimer’s disease (AD) is often comorbid with other pathologies. First, we review shortly the diseases most associated with AD in the clinic. Then we query PubMed citations for the co-occurrence of AD with other diseases, using a list of 400 common pathologies. Significantly, AD is found to be associated with schizophrenia and psychosis, sleep insomnia and apnea, type 2 diabetes, atherosclerosis, hypertension, cardiovascular diseases, obesity, fibrillation, osteoporosis, arthritis, glaucoma, metabolic syndrome, pain, herpes, HIV, alcoholism, heart failure, migraine, pneumonia, dyslipidemia, COPD and asthma, hearing loss, and tobacco smoking. Trivially, AD is also found to be associated with several neurodegenerative diseases, which are disregarded. Notably, our predicted results are consistent with the previously published clinical data and correlate nicely with individual publications. Our results emphasize risk factors and promulgate diseases often associated with AD. Interestingly, the comorbid diseases are often degenerative diseases exacerbated by reactive oxygen species, thus underlining the potential role of antioxidants in the treatment of AD and comorbid diseases.

Background: The majority of metastatic melanoma patients treated with Programed cell Death (PD)-1 blockade fail to achieve durable response. The gut microbiota profoundly affects host immunity, and fecal microbiota transplantations (FMT), which transfers the entire gut microbiota from one host to another, has been shown to enhance anti-PD-1 effectiveness in murine models. We report initial safety and efficacy results from the first three patients treated on a Phase I study of FMT and re-induction anti-PD-1 therapy in anti-PD-1 refractory metastatic melanoma. Methods: FMT donors were two metastatic melanoma patients who achieved a durable complete response. FMT Recipients were metastatic melanoma patients who failed at least one anti-PD-1 line of treatment. FMT was conducted by both colonoscopy and oral ingestion of stool capsules, followed by anti-PD-1 re-treatment (Nivolumab, BMS). Each recipient underwent pre- and post-treatment stool sampling, tissue biopsy of both gut and tumor, and total body imaging. Results: Recipients #1 and #3 received fecal implants from Donor #1, while Recipient #2 receive implants from Donor #2. No FMT-related or immunotherapy-related adverse events were observed. To assess engraftment of the new microbiota, recipients were paired with their respective donors and stool 16S rDNA gene sequence analysis performed. Ideal engraftment from a single donor would result in identical microbiota composition between that donor and recipients. In the case of two donors, ideal engraftment would result in two distinctive recipient-donor compositions. Sequencing results demonstrated post-FMT compositional dissimilarity (Unweighted UniFrac, p=0.04, FDR q=0.22) between the two recipient-donor groups. Immunohistochemical stains of biopsies demonstrated an increased post-FMT infiltration of antigen presenting cells (CD68+) in the gut (paired T test, p=0.008) and in the tumor (p=0.076). Post-treatment intra-tumoral CD8+ T-cells infiltration was also increased (p=0.096), especially in recipients #1, #3. Recipient #1 and Recipient #3 demonstrated clinical and radiological benefit from treatment. Conclusion: FMT in metastatic melanoma patients seemed to be safe and may alter recipient gut microbiota to resemble that of a responder donor. This alteration may result in intra-tumoral T-cell activity, which was translated to a clinical and radiological benefit in two recipients. Citation Format: Erez N. Baruch, Ilan Youngster, Rona Ortenberg, Guy Ben-Betzalel, Lior H. Katz, Adi Lahat, Iris Barshack, Daniela Dick-Necula, Ronac Mamtani, Naamah Bloch, Bella Ungar, Daniel Rotin, Camila Avivi, Liat Anafi, Yael Steinberg-Silman, Nethanel Asher, Ronnie Shapira-Frommer, Tal Brosh-Nissimov, Yael Eshet, Stephen Raskin, Hagit Harati, Jenny Melnichenko, Jacob Schachter, Omry Koren, Gal Markel, Ben Boursi. Fecal microbiota transplantation (FMT) and re-induction of anti-PD-1 therapy in refractory metastatic melanoma patients - preliminary results from a phase I clinical trial (NCT03353402) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr CT042.