Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0024312 (lymphopenia)
 4,859 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The survival benefits of traditional maximum tolerated dose (MTD) cytotoxic therapy have been modest for the treatment of most types of metastatic malignancy and, moreover, often come with increased acute and chronic toxicity. Recent studies have demonstrated that the frequent administration of comparatively low doses of cytotoxic agents, with no extended breaks [low-dose metronomic (LDM) chemotherapy], may not only be at least as efficient as MTD therapy but also less toxic. This coincides with an apparent selectivity for "activated" endothelial cells of the tumor vasculature. However, the impact of LDM chemotherapy on the most sensitive target cell populations normally affected by MTD therapy (i.e., bone marrow progenitors, gut mucosa, and hair follicle cells) has not been analyzed in experimental detail. Therefore, we compared effects of LDM and MTD cyclophosphamide (CTX) on bone marrow and gut mucosa. Furthermore, we studied the potential impact of LDM CTX on angiogenesis in the context of wound healing and evidence of organ toxicity. We show absent or moderate hematologic and intestinal toxicity of LDM as opposed to MTD CTX. Of note was the finding of sustained lymphopenia, which is not unexpected given the use of CTX as immunosuppressive drug. There was no negative impact on wound healing or evidence of organ toxicity. LDM offers clear safety advantages over conventional MTD chemotherapy and therefore would appear to be ideal for long-term combination therapy with targeted antiangiogenic drugs.
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PMID:A comparative analysis of low-dose metronomic cyclophosphamide reveals absent or low-grade toxicity on tissues highly sensitive to the toxic effects of maximum tolerated dose regimens. 1517 13

Targeting angiogenesis in glioblastoma (GBM) may improve patient outcome by normalizing tumor vasculature and improving delivery of chemotherapeutics and oxygen. Consequently, concomitant administration of small molecule inhibitors of the VEGF pathway will likely have a positive impact on chemoradiation treatment outcome. We conducted a Phase I study of vatalanib, a small molecule inhibitor of VEGFR, PDGFR, and c-kit in patients with newly diagnosed GBM receiving radiation, temozolomide, and an enzyme-inducing anti-epileptic drug in order to determine the MTD of vatalanib in this patient population. We incorporated circulating biomarker and SNP analyses and pharmacokinetic studies. Nineteen patients were enrolled and the MTD was not reached at the time of study termination. Vatalanib was well tolerated with only 2 DLTs (thrombocytopenia and elevated transaminases). Other grade 3/4 toxicities included leukopenia, lymphopenia, neutropenia, and hand-foot syndrome. There were no wound-healing complications. Of the 13 patients evaluable for a radiographic response, 2 had a partial response and 9 had stable disease. Vatalanib significantly increased PlGF and sVEGFR1 in plasma circulation and decreased sVEGFR2 and sTie2. Plasma collagen IV increased significantly by day 50 of treatment. Vatalanib was well tolerated and this study demonstrates the safety of oral small molecule inhibitors in newly diagnosed GBM patients. Blood biomarkers may be useful as pharmacodynamic markers of response to anti-angiogenic therapies.
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PMID:Phase I trial with biomarker studies of vatalanib (PTK787) in patients with newly diagnosed glioblastoma treated with enzyme inducing anti-epileptic drugs and standard radiation and temozolomide. 2082 42

There is no approved second-line systemic therapy option for malignant pleural mesothelioma (MPM), but targeting angiogenesis is an area of investigation. PF-03446962 is a fully human antibody against activin receptor-like kinase 1, which is commonly expressed in tumor vasculature. We performed a multicenter, open label, single-arm, two-stage phase II study of PF-03446962 in patients with MPM and progressive disease after platinum-based chemotherapy. In total, 17 patients were enrolled, but no partial or complete responses were observed. The trial did not meet the prespecified response criterion for moving to the second stage. There were only three grade 3 (G3) or higher nonhematological toxicities observed (G3 hypertension [n=2] and G3 fatigue [n=1]) and just one episode of G3 lymphopenia. In conclusion, PF-03446962, despite being generally well tolerated, failed to demonstrate efficacy in the treatment of advanced MPM as a single agent. There are no plans for further investigation of this agent in MPM.
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PMID:A Phase II Study of PF-03446962 in Patients with Advanced Malignant Pleural Mesothelioma. CCTG Trial IND.207. 2744 4