Trial Watch: Therapeutic vaccines in metastatic renal cell carcinoma

Despite the renaissance of cancer immunotherapy, no novel immunotherapy has been approved for the treatment of renal cell cancer (RCC) since the availability of recombinant cytokines (interleukin-2, interferon-α). All vaccine trials have failed to meet their endpoints although they have highlighted potential predictive biomarkers (e.g., pre-existing immune response, hematological parameters, tumor burden). Recent advances in immunomodulatory therapies have prompted the study of combination treatments targeting the tumor immunosuppressive microenvironment consisting of regulatory T-cells (Treg), myeloid suppressor cells, and cytokines. Approaches under investigation are use of inhibitors to curb the overexpression of immune checkpoint ligands by tumor cells (e.g., anti-CTLA-4, anti-PD-1/PD-L1) and exploiting the immunomodulatory effects of anti-angiogenic agents that are the current standard of metastatic RCC care. Phase III trials are focusing on the possible synergy between therapeutic vaccines (e.g., IMA-901 and AGS-003) and anti-angiogenic agents.

VEGF-A modulates expression of inhibitory checkpoints on CD8+ T cells in tumors

Immune escape is a prerequisite for tumor development. To avoid the immune system, tumors develop different mechanisms, including T cell exhaustion, which is characterized by expression of immune inhibitory receptors, such as PD-1, CTLA-4, Tim-3, and a progressive loss of function. The recent development of therapies targeting PD-1 and CTLA-4 have raised great interest since they induced long-lasting objective responses in patients suffering from advanced metastatic tumors. However, the regulation of PD-1 expression, and thereby of exhaustion, is unclear. VEGF-A, a proangiogenic molecule produced by the tumors, plays a key role in the development of an immunosuppressive microenvironment. We report in the present work that VEGF-A produced in the tumor microenvironment enhances expression of PD-1 and other inhibitory checkpoints involved in CD8(+) T cell exhaustion, which could be reverted by anti-angiogenic agents targeting VEGF-A-VEGFR. In view of these results, association of anti-angiogenic molecules with immunomodulators of inhibitory checkpoints may be of particular interest in VEGF-A-producing tumors.

VEGF-A modulates expression of inhibitory checkpoints on CD8+ T cells in tumors

VEGF-A production in the tumor microenvironment enhances expression of PD-1 and other inhibitory checkpoints involved with CD8⁺ T cell exhaustion, which can be reversed with anti-VEGF/VEGFR treatment.

Immune escape is a prerequisite for tumor development. To avoid the immune system, tumors develop different mechanisms, including T cell exhaustion, which is characterized by expression of immune inhibitory receptors, such as PD-1, CTLA-4, Tim-3, and a progressive loss of function. The recent development of therapies targeting PD-1 and CTLA-4 have raised great interest since they induced long-lasting objective responses in patients suffering from advanced metastatic tumors. However, the regulation of PD-1 expression, and thereby of exhaustion, is unclear. VEGF-A, a proangiogenic molecule produced by the tumors, plays a key role in the development of an immunosuppressive microenvironment. We report in the present work that VEGF-A produced in the tumor microenvironment enhances expression of PD-1 and other inhibitory checkpoints involved in CD8⁺ T cell exhaustion, which could be reverted by anti-angiogenic agents targeting VEGF-A–VEGFR. In view of these results, association of anti-angiogenic molecules with immunomodulators of inhibitory checkpoints may be of particular interest in VEGF-A-producing tumors.

Rechallenge with mTOR inhibitors in metastatic renal cell carcinoma patients who progressed on previous mTOR inhibitor therapy

OBJECTIVE

To determine if mammalian target of rapamycin (mTOR) inhibitor (everolimus or temsirolimus) rechallenge in the third- or fourth-line setting after sequential use of a vascular endothelial growth factor receptor (VEGF)-targeted agent and an mTOR inhibitor is a feasible and effective treatment strategy in patients with metastatic renal cell carcinoma (mRCC).

METHODS

Patients who received a VEGF-targeted agent, an mTOR inhibitor and rechallenge with a second mTOR inhibitor at 2 institutions (Hôpital Européen Georges-Pompidou and Vienna Medical School) between 30 March 2001 and 15 September 2011 were included. Analyses of radiographic images were performed according to the Response Evaluation Criteria in Solid Tumors, version 1.0, to determine the objective response rate and treatment duration (TD).

RESULTS

Twelve patients met the inclusion criteria. Following 1 or 2 VEGF receptor-tyrosine kinase inhibitors, 7 patients firstly received everolimus and 5 patients received temsirolimus. Irrespective of treatment sequence, 6 of 12 patients (50%) responded to everolimus and 4 of 12 patients (33%) responded to temsirolimus; 3 patients (25%) did not respond to either. Median TDs (95% confidence interval) for everolimus → temsirolimus and temsirolimus → everolimus sequences were 10.3 months (8.8-19.2 months) and 5.8 months (2.9-19.3 months), respectively.

CONCLUSIONS

Despite the limited number of patients, this highlights the feasibility of utilizing mTOR rechallenge as an integral part of sequential treatment strategies in mRCC.

Metastatic renal cell carcinoma treated sequentially with multiple VEGF receptor-targeted inhibitors--a case report

Six targeted agents [sorafenib, sunitinib, temsirolimus, bevacizumab (plus interferon), everolimus and pazopanib] have been approved for the treatment of patients with metastatic renal cell carcinoma. As disease progression is inevitable, most patients will receive several lines of treatment. However, the choice regarding which sequence of drugs to use remains unclear, particularly concerning the drug class, i.e. those targeting the vascular endothelial growth factor (receptor) [VEGF(R)] pathway versus those acting on the mammalian target of rapamycin pathway. There appears to be no absolute crossresistance between tyrosine kinase inhibitors (TKIs) acting on the VEGF(R) pathway, and there have been numerous reports of two TKIs being successfully used in sequence. We report the case of a 63-year-old woman who responded for 24 months to three successive lines of treatment with different TKIs (sunitinib, axitinib and sorafenib). This suggests that TKIs targeting VEGFR should be considered as individual drugs and not as a single class.

Molecular characterization of rotavirus strains circulating among children with acute gastroenteritis in Madagascar during 2004-2005

A survey was undertaken of the etiology of acute gastroenteritis in children <16 years of age in Antananarivo, Madagascar, from May 2004 through May 2005. With use of electron microscopy of fecal specimens, 104 (36%) of 285 children were found to be infected with rotavirus. Rotavirus strain characterization was undertaken using enzyme-linked immunosorbent assay, electropherotyping, reverse-transcription polymerase chain reaction genotyping, and nucleotide sequencing. The predominant group A rotavirus strain types identified were P[4]G2 (62%) and P[8]G9 (23%). Nucleotide sequence analysis of the VP7 genes of selected Malagasy G2 and G9 strains demonstrated similarity with those of other recently identified African rotavirus strains belonging to the same genotype.

Cryptosporidium species causing acute diarrhoea in children in Antananarivo, Madagascar

A 13-month study of children presenting with acute diarrhoeal disease at hospitals and rehydration clinics in Antananarivo, Madagascar, was undertaken between May 2004 and May 2005. Cryptosporidiosis accounted for diarrhoea in 12 (5.6%) of the 215 children investigated. Cases of cryptosporidiosis were detected only in the rainy season, and the median age of cases was 13.5 months (range=1 day-27 months). As 11 of the cases of cryptosporidiosis were caused by Cryptosporidium hominis and only one by C. parvum, most of the cases were probably the result of anthroponotic transmission. GP60/45/15 gene polymorphisms indicated that the causative pathogens were of subtypes Ia, Id, Ie and IIc.

[Diagnosis of malaria in Antananarivo City: examination of the results obtained at the Institut Pasteur de Madagascar from 2001 to 2004]

Malaria diagnosis is part of the daily activities of the Clinical Biology Center (CBC) of the Institut Pasteur de Madagascar in Antananarivo. Over a period of four years (2001-2004), regardless the methods being used, out of 6537 blood samples examined, 159 (2.43%) tests were positive. All four species of Plasmodium infecting human. were detected with a high prevalence of P. falciparum (87.2%). 49/159 patients were foreigners, but their files did not allow us to distinguish imported from locally acquired malaria cases. Also, among Malagasy patients, there was no possibility to recognize introduced malaria cases (contracted in coastal areas). In Madagascar malaria remains a public health problem. But fever and recent history of fever are often considered and treated as malaria. Our results demonstrated that confirmed malaria rate was very low. Reporting malaria on the basis of clinical signs overestimates malaria cases at the national level. The importance of malaria biological diagnosis is discussed in this article.

HIV-1-related morbidity in adults, Abidjan, Côte d'Ivoire: a nidus for bacterial diseases

We studied mortality and morbidity in 270 HIV-1-infected adults (60% women, median age 31 years, mean baseline CD4 count 331/mm(3) ) observed in a follow-up that lasted a median 10 months in Côte d'Ivoire. Survival and probability of remaining free from any episode of morbidity at 12 months were 0.80 and 0.50, respectively. Baseline CD4 count <200/mm(3) was the only variable associated with global morbidity and mortality, with hazard ratios of 2.50 and 7.57, respectively. The most frequent causes of morbidity were severe bacterial infections (incidence rate: 26.1 per 100 person-years [py]), followed by oral candidiasis (22.3% py), unexplained weight loss over 10% of baseline body weight (13.3% py), tuberculosis (10.1% py), unexplained chronic diarrhea (9.7% py), and isosporiasis (5.1% py). Nontyphoid Salmonella accounted for 37% of isolated strains during severe bacterial infections, followed by Streptococcus pneumoniae (34%), Escherichia coli (15%), and Shigella species (7%). A significant part of bacterial morbidity occurred in patients with baseline CD4 count > or = 200/mm(3), in whom the incidence rate of bacterial diseases was 21.3% py and the probability of remaining free from any bacterial infection at 12 months was 0.80 (vs. 36.4% py and 0.71 in patients with baseline CD4 count <200/mm(3); p =.07).

[Causes of fever in adults infected by HIV-1. Ambulatory follow-up in the ANRS 059 trial in Abidjan, Ivory Coast]

OBJECTIVE

Describe the causes of fever in HIV-1 infected adults in Abidjan, Ivory Coast.

METHODS

Exhaustive analysis of all the morbid episodes with raise in temperature to above 37.5 degrees C in patients followed-up prospectively, within the framework of the ANRS 059 study from April 1996 to March 1998.

RESULTS

One hundred and four patients presented 269 episodes of fever. At the start of these episodes, the mean CD4 count was of 311/mm3, fever had lasted a mean of 3.4 days and mean body temperature was 38.7 degrees C. The 269 episodes lead to 288 diagnoses: 152 specific etiologic diagnoses and 136 non-specific syndrome diagnoses. Community bacterial infections represented 55% of the specific diagnoses, followed by malaria (16%) and tuberculosis (12%). The mean CD4 count during the bacterial episodes was 208/mm3, in malaria 384/mm3 and in tuberculosis 245/mm3. Non-typhi salmonella, pneumococci and Escherischia coli represented 37%, 32%, and 15% respectively of the bacteria isolated. The mean duration between the first and last day of fever was 8.4 days. This time lapse was superior or equal to 30 days in 22 episodes (8%), 50% of which were mycobacterioses (36% tuberculosis and 14% atypic mycobacterioses). Nineteen episodes (7%) lead to death within a mean delay of 58 days. The first cause of death was atypic mycobacteriosis (26%). Death was significantly associated with a CD4 count < 200/mm3 and to prolongation of fever for more than 30 days.

CONCLUSION

Other than the frequently described role of tuberculosis in HIV morbidity in sub-Saharian Africa, the role of bacterial diseases, responsible for early death, potentially severe, but curable should be underlined. The diffusion of antibiotic treatment algorithms adapted to the principle clinical syndromes encountered, might improve the treatment of adults infected by HIV consulting in sub-Saharian Africa.

Spontaneous pneumothorax: pragmatic management and long-term outcome

We prospectively considered 65 patients admitted for a spontaneous pneumothorax (SP) to describe the pragmatic management of SP, the first recurrence-free interval after medical therapeutic procedure and to specify the first recurrence risk factors over a 7-year period in these patients treated medically. The treatment options were observation alone (9%), needle aspiration (6%), small calibre chest tube (Pleurocatheter) drainage (28%) or thoracic tube drainage (49%), and pleurodesis with video-assisted thoracic surgery procedure (8%). Duration of the drainage and length of hospital stay were shorter in the Pleurocatheter group than in the thoracic tube group (P < 0.01). Among the 47 patients (72%) with a first SP and treated medically, nine patients (19%) had a first homolateral recurrence (FHR) during a mean follow-up of 84+/-13 months. Recurrence-free intervals ranged from 1 to 24 months (mean +/- SD: 9.3+/-8.4 months). FHR cases were more frequent in the Pleurocatheter group (P < 0 04). Analysis of potential risk factors showed that the patient's height and a previous homolateral SP episode are independent recurrence risk factors.

Hepatitis B and C infections, human immunodeficiency virus and other sexually transmitted infections among women of childbearing age in Côte d'Ivoire, West Africa

Few studies have been conducted in developing countries to estimate the prevalence of hepatitis C virus (HCV) infection and its association with human immunodeficiency virus (HIV) and other sexually transmitted diseases (STDs). We have screened for hepatitis B virus (HBV) and HCV markers 200 HIV-1-positive, 23 HIV-2-positive and 206 HIV-negative women attending gynaecology clinics in 1995/96 in Abidjan, Côte d'Ivoire, a sample selected among 2198 consecutive consultants. Taking into account the prevalence of 21.7% for HIV in this population, the overall prevalence of anti-HBV core antibody was 81.6%, that for hepatitis B surface antigen was 9.9% and for HCV antibody was 3.3%. HIV infection and other STDs were not associated with HBV or HCV markers. Moreover, HBV and HCV markers were not statistically associated. Our results confirm the high prevalence of HIV in Abidjan and the endemic situation of HBV infection. Furthermore, HCV infection is not infrequent in this developing country setting, not explained by sexual transmission.