Experience in daily practice with ipilimumab for the treatment of patients with metastatic melanoma: an early increase in lymphocyte and eosinophil counts is associated with improved survival

BACKGROUND

Ipilimumab is a recently approved immunotherapy that has demonstrated an improvement in the overall survival (OS) of patients with metastatic melanoma. We report a single-institution experience in patients treated in a compassionate-use program.

PATIENTS AND METHODS

In this prospective study, patients were treated between June 2010 and September 2011. Inclusion criteria were a diagnosis of unresectable stage III or IV melanoma, at least one previous line of chemotherapy, and survival 12 weeks after the first perfusion. Four courses of ipilimumab were administered at a dose of 3 mg/kg every 3 weeks.

RESULTS

Seventy-three patients were included. Median OS was 9.1 months (95% CI 6.4-11.3) from the start of ipilimumab. Immune-related adverse events were observed in 45 patients (62%), including 19 grade 3-4 events (26%). No drug-related death occurred. A lymphocyte count >1000/mm(3) at the start of the second course and an increase in the eosinophil count >100/mm(3) between the first and second infusions were correlated with an improved OS.

CONCLUSION

Ipilimumab toxic effect is manageable in real life. Biological data such as lymphocyte and eosinophil counts at the time of the second ipilimumab infusion appear to be early markers associated with better OS.

The gut microbiota of a patient with resistant tuberculosis is more comprehensively studied by culturomics than by metagenomics

Gut microbiota consists of 10(10) bacteria per gram of stool. Many antibiotic regimens induce a reduction in both the diversity and the abundance of the gut flora. We analyzed one stool sample collected from a patient treated for drug-resistant Mycobacterium tuberculosis and who ultimately died from pneumonia due to a Streptococcus pneumoniae 10 months later. We performed microscopic observation, used 70 culture conditions (microbial culturomics) with identification by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF) and 16S rRNA amplification and sequencing, pyrosequencing, and 18S rRNA amplification and clone sequencing. Electron and optical microscopic observations revealed the presence of yeast, but no bacterial species were observed. By culture, only 39 bacterial species were identified, including one new species, as well as three species that have not been previously observed in the human gut. The pyrosequencing showed only 18 phylotypes, detecting a lower number of bacterial species than the culture techniques. Only two phylotypes overlapped with culturomics. In contrast, an amount of chloroplasts was found. Additionally, specific molecular eukaryote detection found three fungal species. We recovered, for the first time, more cultivable than non-cultivable bacterial species in a patient with a low bacterial load in the gut, demonstrating the depth bias of pyrosequencing. We propose that the desertification of gut microbiota in this patient is a reflection of the total body microbiota and may have contributed to the invasive infection of S. pneumoniae. This finding suggests that caution should be applied when treating patients with broad-spectrum antibiotics, and preventive measures should be taken in order to avoid invasive infection.

Microbial culturomics: paradigm shift in the human gut microbiome study

Comprehensive determination of the microbial composition of the gut microbiota and the relationships with health and disease are major challenges in the 21st century. Metagenomic analysis of the human gut microbiota detects mostly uncultured bacteria. We studied stools from two lean Africans and one obese European, using 212 different culture conditions (microbial culturomics), and tested the colonies by using mass spectrometry and 16S rRNA amplification and sequencing. In parallel, we analysed the same three samples by pyrosequencing 16S rRNA amplicons targeting the V6 region. The 32 500 colonies obtained by culturomics have yielded 340 species of bacteria from seven phyla and 117 genera, including two species from rare phyla (Deinococcus-Thermus and Synergistetes, five fungi, and a giant virus (Senegalvirus). The microbiome identified by culturomics included 174 species never described previously in the human gut, including 31 new species and genera for which the genomes were sequenced, generating c. 10 000 new unknown genes (ORFans), which will help in future molecular studies. Among these, the new species Microvirga massiliensis has the largest bacterial genome so far obtained from a human, and Senegalvirus is the largest virus reported in the human gut. Concurrent metagenomic analysis of the same samples produced 698 phylotypes, including 282 known species, 51 of which overlapped with the microbiome identified by culturomics. Thus, culturomics complements metagenomics by overcoming the depth bias inherent in metagenomic approaches.

Use of a serum-free reconstituted epidermis as a skin pharmacological model

This study is aimed at assessing some of the possibilities offered by a new kind of three-dimensional skin culture in the field of toxicity and skin inflammation. The Reconstituted Epidermis used is presently the only skin model on the market in which normal human keratinocytes are allowed to grow and to differentiate in a chemically defined culture medium. The response of this original tissue to chemical (anionic and cationic surfactants) and physical (UVB radiation) insults was compared with human keratinocytes in monolayer culture and assessed through histological analysis, cell viability quantification and interleukin-1alpha (IL-1alpha) release measurement. For the surfactants and the UVB radiation a clear relationship was shown between the amount of IL-1alpha released and both the cell viability and the histological appearance of the skin. Sublethal doses of UV radiation induced exclusively an increase of intracellular amount of IL-1alpha, the magnitude of which seemed to be time dependent. The irritating potential of various kinds of cosmetic creams was then assessed using this skin model and compared with human irritation data. The intensity of erythema and oedema induced by a 48-hr human patch test was consistent with the amount of IL-1alpha secreted in the medium, the histological appearance of the Reconstituted Epidermis and the cell viability.

Sequential research-related biopsies in phase I trials: acceptance, feasibility and safety

BACKGROUND

Sequential tumour biopsies are of potential interest for the rational development of molecular targeted therapies.

PATIENTS AND METHODS

From June 2004 to July 2009, 186 patients participated in 14 phase I clinical trials in which sequential tumour biopsies (13 trials) and/or sequential normal skin biopsies (6 trials) were optional. All patients had to sign an independent informed consent for the biopsies.

RESULTS

Tumour biopsies were proposed to 155 patients and 130 (84%) signed the consent while normal skin biopsies were proposed to 70 patients and 57 (81%) signed the consent. Tumour biopsies could not be carried out in 41 (31%) of the 130 consenting patients. Tumour biopsies were collected at baseline in 33 patients, at baseline and under treatment in 56 patients. Tumour biopsies were obtained using an 18-gauge needle, under ultrasound or computed tomography guidance. Only nine minor complications were recorded. Most tumour biopsy samples collected were intended for ancillary molecular studies including protein or gene expression analysis, comparative genomic hybridization array or DNA sequencing. According to the results available, 70% of the biopsy samples met the quality criteria of each study and were suitable for ancillary studies.

CONCLUSIONS

In our experience, the majority of the patients accepted skin biopsies as well as tumour biopsies. Sequential tumour and skin biopsies are feasible and safe during early-phase clinical trials, even when patients are exposed to anti-angiogenic agents. The real scientific value of such biopsies for dose selection in phase I trials has yet to be established.