Long-Term Results Of Autologous Hematopoietic Cell Transplantation For Peripheral T Cell Lymphoma: The Stanford Experience

AbstractThe peripheral T cell lymphomas (PTCL) carry a worse prognosis compared to B cell non-Hodgkin lymphoma. There is no uniform standard therapy for PTCL, and autologous hematopoietic cell transplant (AHCT) is often offered as consolidation in first remission or at relapse because of the poor outcomes with conventional therapy. We conducted a retrospective review of patients who underwent AHCT for PTCL from 1989 to 2006. Fifty-three cases were identified consisting of systemic anaplastic large cell (n = 18), PTCL unspecified (n = 17), angioimmunoblastic (n = 9), nasal type extranodal NK/T (n = 7), hepatosplenic (n = 2), and adult T cell leukemia/lymphoma (n = 1). Fifteen patients were transplanted in first complete or partial response (CR1/PR1), 32 in second or beyond CR or PR (CR2/PR2+), and 11 with primary refractory disease (REF). With a median follow-up was 5 years (range: 1.0-11.5), the 5-year progression-free survival (PFS) and overall survival (OS) were 25% and 48%, respectively. Disease status at AHCT had a significant impact on PFS and OS. The 5-year PFS for patients in CR1/PR1, CR2/PR2+, and REF was 51%, 12%, and 0%, respectively, and the corresponding figures for OS were 76%, 40%, and 30%, respectively. The pretransplant factors that impacted survival were disease status and the number of prior regimens. Histology, age, sex, stage, B symptoms, bone marrow involvement, and duration of first response did not significantly affect PFS or OS. Based on these results, AHCT as consolidation therapy in first complete or partial response may offer a durable survival benefit. However, AHCT with conventional salvage chemotherapy has minimal durable benefit in patients with relapsed or refractory PTCL, and thus novel strategies and/or allogeneic HCT should be more aggressively explored in lieu of AHCT for relapsed/ refractory PTCL

How fast is fast? Eco-evolutionary dynamics and rates of change in populations and phenotypes

It is increasingly recognized that evolution may occur in ecological time. It is not clear, however, how fast evolution – or phenotypic change more generally – may be in comparison with the associated ecology, or whether systems with fast ecological dynamics generally have relatively fast rates of phenotypic change. We developed a new dataset on standardized rates of change in population size and phenotypic traits for a wide range of species and taxonomic groups. We show that rates of change in phenotypes are generally no more than 2/3, and on average about 1/4, the concurrent rates of change in population size. There was no relationship between rates of population change and rates of phenotypic change across systems. We also found that the variance of both phenotypic and ecological rates increased with the mean across studies following a power law with an exponent of two, while temporal variation in phenotypic rates was lower than in ecological rates. Our results are consistent with the view that ecology and evolution may occur at similar time scales, but clarify that only rarely do populations change as fast in traits as they do in abundance

31st Annual Meeting and Associated Programs of the Society for Immunotherapy of Cancer (SITC 2016) : part two

Background The immunological escape of tumors represents one of the main ob- stacles to the treatment of malignancies. The blockade of PD-1 or CTLA-4 receptors represented a milestone in the history of immunotherapy. However, immune checkpoint inhibitors seem to be effective in specific cohorts of patients. It has been proposed that their efficacy relies on the presence of an immunological response. Thus, we hypothesized that disruption of the PD-L1/PD-1 axis would synergize with our oncolytic vaccine platform PeptiCRAd. Methods We used murine B16OVA in vivo tumor models and flow cytometry analysis to investigate the immunological background. Results First, we found that high-burden B16OVA tumors were refractory to combination immunotherapy. However, with a more aggressive schedule, tumors with a lower burden were more susceptible to the combination of PeptiCRAd and PD-L1 blockade. The therapy signifi- cantly increased the median survival of mice (Fig. 7). Interestingly, the reduced growth of contralaterally injected B16F10 cells sug- gested the presence of a long lasting immunological memory also against non-targeted antigens. Concerning the functional state of tumor infiltrating lymphocytes (TILs), we found that all the immune therapies would enhance the percentage of activated (PD-1pos TIM- 3neg) T lymphocytes and reduce the amount of exhausted (PD-1pos TIM-3pos) cells compared to placebo. As expected, we found that PeptiCRAd monotherapy could increase the number of antigen spe- cific CD8+ T cells compared to other treatments. However, only the combination with PD-L1 blockade could significantly increase the ra- tio between activated and exhausted pentamer positive cells (p= 0.0058), suggesting that by disrupting the PD-1/PD-L1 axis we could decrease the amount of dysfunctional antigen specific T cells. We ob- served that the anatomical location deeply influenced the state of CD4+ and CD8+ T lymphocytes. In fact, TIM-3 expression was in- creased by 2 fold on TILs compared to splenic and lymphoid T cells. In the CD8+ compartment, the expression of PD-1 on the surface seemed to be restricted to the tumor micro-environment, while CD4 + T cells had a high expression of PD-1 also in lymphoid organs. Interestingly, we found that the levels of PD-1 were significantly higher on CD8+ T cells than on CD4+ T cells into the tumor micro- environment (p < 0.0001). Conclusions In conclusion, we demonstrated that the efficacy of immune check- point inhibitors might be strongly enhanced by their combination with cancer vaccines. PeptiCRAd was able to increase the number of antigen-specific T cells and PD-L1 blockade prevented their exhaus- tion, resulting in long-lasting immunological memory and increased median survival

Pollinator assemblage and pollen load differences on sympatric diploid and tetraploid cytotypes of the desert-dominant Larrea tridentata

PREMISE: Whole-genome duplication (polyploidy) is an important force shaping flowering plant evolution. Ploidy-specific plant–pollinator interactions represent important community-level biotic interactions that can lead to nonrandom mating and the persistence of mixed-ploidy populations. METHODS: At a naturally occurring diploid–tetraploid contact zone of the autopolyploid desert shrub Larrea tridentata, we combined flower phenology analyses, collections of bees on plants of known cytotype, and flow cytometry analyses of bee-collected pollen loads to investigate whether (1) diploid and tetraploid plants have unique bee pollinator assemblages, (2) bee taxa exhibit ploidy-specific visitation and pollen collection biases, and (3) specialist and generalist bee taxa have ploidy-specific visitation and pollen collection biases. RESULTS: Although bee assemblages overlapped, we found significant differences in bee visitation to co-occurring diploids and tetraploids, with the introduced honeybee (Apis mellifera) and one native species (Andrena species 12) more frequently visiting tetraploids. Consistent with bee assemblage differences, we found that diploid pollen was overrepresented among pollen loads on native bees, while pollen loads on A. mellifera did not deviate from the random expectation. However, mismatches between the ploidy of pollen loads and plants were common, consistent with ongoing intercytotype gene flow. CONCLUSIONS: Our data are consistent with cytotype-specific bee visitation and suggest that pollinator behavior contributes to reduced diploid–tetraploid mating. Differences in bee visitation and pollen movement potentially contribute to an easing of minority cytotype exclusion and the facilitation of cytotype co-occurrence