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result(s) for
"Angulo-Gonzalez, David"
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Posaconazole vs. Fluconazole or Itraconazole Prophylaxis in Patients with Neutropenia
2007
In this randomized trial of patients undergoing treatment for acute myelogenous leukemia or the myelodysplastic syndrome, prophylaxis with posaconazole resulted in fewer fungal infections and longer survival than did prophylaxis with fluconazole or itraconazole. The difference was primarily due to a lower rate of invasive aspergillosis in the posaconazole group.
In patients undergoing treatment for acute myelogenous leukemia or the myelodysplastic syndrome, prophylaxis with posaconazole resulted in fewer fungal infections and longer survival than did prophylaxis with fluconazole or itraconazole.
Invasive fungal infections remain a major cause of illness and death in patients with neutropenia who have hematologic cancers, despite the availability of new antifungal agents. The incidence of proven or probable mold and yeast infections can reach 24% among patients with leukemia.
1
,
2
Reported mortality from candidiasis or aspergillosis ranges from 40 to 50%, and mortality from fusariosis or zygomycosis is 70% or more.
3
–
8
Prophylaxis is a commonly used treatment strategy, because the diagnosis of fungal infection is often delayed or difficult to establish with certainty, and a delay in antifungal treatment increases mortality.
9
–
11
Antifungal prophylaxis with . . .
Journal Article
Profiling of residual breast cancers after neoadjuvant chemotherapy identifies DUSP4 deficiency as a mechanism of drug resistance
by
Granja-Ingram, Nara M
,
Meszoely, Ingrid M
,
Stemke-Hale, Katherine
in
692/53
,
692/699/67/1059/2326
,
692/699/67/1347
2012
By digital profiling of residual breast tumors after neoadjuvant therapy, the authors identify gene expression patterns that correspond with a higher risk of metastasis and recurrence. Activation of the Ras-ERK pathway through loss of DUSP4 confers therapy resistance that can be overcome by combined treatment with MEK inhibitors.
Neoadjuvant chemotherapy (NAC) induces a pathological complete response (pCR) in ∼30% of patients with breast cancer. However, many patients have residual cancer after chemotherapy, which correlates with a higher risk of metastatic recurrence and poorer outcome than those who achieve a pCR. We hypothesized that molecular profiling of tumors after NAC would identify genes associated with drug resistance. Digital transcript counting was used to profile surgically resected breast cancers after NAC. Low concentrations of dual specificity protein phosphatase 4 (DUSP4), an ERK phosphatase, correlated with high post-NAC tumor cell proliferation and with basal-like breast cancer (BLBC) status. BLBC had higher DUSP4 promoter methylation and gene expression patterns of Ras-ERK pathway activation relative to other breast cancer subtypes. DUSP4 overexpression increased chemotherapy-induced apoptosis, whereas DUSP4 depletion dampened the response to chemotherapy. Reduced DUSP4 expression in primary tumors after NAC was associated with treatment-refractory high Ki-67 scores and shorter recurrence-free survival. Finally, inhibition of mitogen-activated protein kinase kinase (MEK) synergized with docetaxel treatment in BLBC xenografts. Thus, DUSP4 downregulation activates the Ras-ERK pathway in BLBC, resulting in an attenuated response to anti-cancer chemotherapy.
Journal Article
Phase II trial of AKT inhibitor MK-2206 in patients with advanced breast cancer who have tumors with PIK3CA or AKT mutations, and/or PTEN loss/PTEN mutation
2019
Background
The PI3K/AKT pathway is activated through PIK3CA or AKT1 mutations and PTEN loss in breast cancer. We conducted a phase II trial with an allosteric AKT inhibitor MK-2206 in patients with advanced breast cancer who had tumors with PIK3CA/AKT1 mutations and/or PTEN loss/mutation.
Methods
The primary endpoint was objective response rate (ORR). Secondary endpoints were 6-month progression-free survival (6 m PFS), predictive and pharmacodynamic markers, safety, and tolerability. Patients had pre-treatment and on-treatment biopsies as well as collection of peripheral blood mononuclear cells (PBMC) and platelet-rich plasma (PRP). Next-generation sequencing, immunohistochemistry, and reverse phase protein arrays (RPPA) were performed.
Results
Twenty-seven patients received MK-2206. Eighteen patients were enrolled into the
PIK3CA/AKT1
mutation arm (cohort A): 13 had
PIK3CA
mutations, four had
AKT1
mutations, and one had a
PIK3CA
mutation as well as PTEN loss. ORR and 6 m PFS were both 5.6% (1/18), with one patient with HR+ breast cancer and a
PIK3CA
E542K mutation experiencing a partial response (on treatment for 36 weeks). Nine patients were enrolled on the PTEN loss/mutation arm (cohort B). ORR was 0% and 6 m PFS was 11% (1/9), observed in a patient with triple-negative breast cancer and PTEN loss. The study was stopped early due to futility. The most common adverse events were fatigue (48%) and rash (44%). On pre-treatment biopsy,
PIK3CA
and
AKT1
mutation status was concordant with archival tissue testing. However, two patients with PTEN loss based on archival testing had PTEN expression on the pre-treatment biopsy. MK-2206 treatment was associated with a significant decline in pAKT S473 and pAKT T308 and PI3K activation score in PBMC and PRPs, but not in tumor biopsies. By IHC, there was no significant decrease in median pAKT S473 or Ki-67 staining, but a drop was observed in both responders.
Conclusions
MK-2206 monotherapy had limited clinical activity in advanced breast cancer patients selected for PIK3CA/AKT1 or PTEN mutations or PTEN loss. This may, in part, be due to inadequate target inhibition at tolerable doses in heavily pre-treated patients with pathway activation, as well as tumor heterogeneity and evolution in markers such as PTEN conferring challenges in patient selection.
Trial registration
ClinicalTrials.gov,
NCT01277757
. Registered 13 January 2011.
Journal Article
Priority-Setting for Novel Drug Regimens to Treat Tuberculosis: An Epidemiologic Model
by
Nuermberger, Eric
,
Forissier, Thomas
,
Rich, Michael L.
in
Antitubercular Agents - therapeutic use
,
Clinical Protocols
,
Drug therapy
2017
Novel drug regimens are needed for tuberculosis (TB) treatment. New regimens aim to improve on characteristics such as duration, efficacy, and safety profile, but no single regimen is likely to be ideal in all respects. By linking these regimen characteristics to a novel regimen's ability to reduce TB incidence and mortality, we sought to prioritize regimen characteristics from a population-level perspective.
We developed a dynamic transmission model of multi-strain TB epidemics in hypothetical populations reflective of the epidemiological situations in India (primary analysis), South Africa, the Philippines, and Brazil. We modeled the introduction of various novel rifampicin-susceptible (RS) or rifampicin-resistant (RR) TB regimens that differed on six characteristics, identified in consultation with a team of global experts: (1) efficacy, (2) duration, (3) ease of adherence, (4) medical contraindications, (5) barrier to resistance, and (6) baseline prevalence of resistance to the novel regimen. We compared scale-up of these regimens to a baseline reflective of continued standard of care. For our primary analysis situated in India, our model generated baseline TB incidence and mortality of 157 (95% uncertainty range [UR]: 113-187) and 16 (95% UR: 9-23) per 100,000 per year at the time of novel regimen introduction and RR TB incidence and mortality of 6 (95% UR: 4-10) and 0.6 (95% UR: 0.3-1.1) per 100,000 per year. An optimal RS TB regimen was projected to reduce 10-y TB incidence and mortality in the India-like scenario by 12% (95% UR: 6%-20%) and 11% (95% UR: 6%-20%), respectively, compared to current-care projections. An optimal RR TB regimen reduced RR TB incidence by an estimated 32% (95% UR: 18%-46%) and RR TB mortality by 30% (95% UR: 18%-44%). Efficacy was the greatest determinant of impact; compared to a novel regimen meeting all minimal targets only, increasing RS TB treatment efficacy from 94% to 99% reduced TB mortality by 6% (95% UR: 1%-13%, half the impact of a fully optimized regimen), and increasing the efficacy against RR TB from 76% to 94% lowered RR TB mortality by 13% (95% UR: 6%-23%). Reducing treatment duration or improving ease of adherence had smaller but still substantial impact: shortening RS TB treatment duration from 6 to 2 mo lowered TB mortality by 3% (95% UR: 1%-6%), and shortening RR TB treatment from 20 to 6 mo reduced RR TB mortality by 8% (95% UR: 4%-13%), while reducing nonadherence to the corresponding regimens by 50% reduced TB and RR TB mortality by 2% (95% UR: 1%-4%) and 6% (95% UR: 3%-10%), respectively. Limitations include sparse data on key model parameters and necessary simplifications to model structure and outcomes.
In designing clinical trials of novel TB regimens, investigators should consider that even small changes in treatment efficacy may have considerable impact on TB-related incidence and mortality. Other regimen improvements may still have important benefits for resource allocation and outcomes such as patient quality of life.
Journal Article
Parasites in Mexican patients with irritable bowel syndrome: a case-control study
by
Kawa-Karasik, Simon
,
Ramirez-Miranda, Maria Elena
,
Pagaza-Melero, Carlos
in
Biomedical and Life Sciences
,
Biomedicine
,
Blastocystis
2010
One hundred and fifteen patients with symptoms suggestive of irritable bowel syndrome (IBS) according to Rome III criteria and 209 patients with gastrointestinal symptoms different from IBS (control) were identified through medical records from the Gastroenterology Clinic of the \"Dr. Manuel Gea Gonzalez General Hospital\" from January 2008 to March 2010. No statistical differences in IBS data as compared with control groups were observed except in bloating, that was more frequent in the IBS group (P = 0.043). Although the pathogenicity of specific intestinal protozoa could not be demonstrated due to lack of association with the development of gastrointestinal symptoms, Blastocystis spp, in the IBS group, exhibited a trend of association to diarrhoea (odds ratio = 2.73, 95% confidence interval = 0.84-8.80, P = 0.053), while having any parasite and diarrhoea was significant (odds ratio = 3.38, 95% confidence interval = 1.33-8.57, P = 0.008). The association between Blastocystis and diarrhoea in IBS patients although not conclusive is an interesting finding; nonetheless more extensive case-controlled studies are required to clearly define the role of some \"non-pathogenic\" parasites in intestinal disease and IBS.
Journal Article