There is no difference in ORR, TTP, and OS for patients treated with the FOLFIRI or FOLFOX4 regimen. Both therapies seemed effective as first-line treatment in these patients. The difference between these two combination therapies is mainly in the toxicity profile.
Purpose: We are interested in identifying mechanisms of resistance to the current generation of antibody-drug conjugates (ADC) and developing ADCs that can overcome this resistance.Experimental Design: Pinatuzumab vedotin (anti-CD22-vc-MMAE) and polatuzumab vedotin are ADCs that contain the microtubule inhibitor monomethyl auristatin E (MMAE) attached to the antibody by the proteasecleavable linker maleimidocaproyl-valine-citrulline-p-aminobenzoyloxycarbonyl (MC-vc-PAB). Early clinical trial data suggest that these ADCs have promising efficacy for the treatment of nonHodgkin lymphoma (NHL); however, some patients do not respond or become resistant to the ADCs. Anthracyclines are very effective in NHL, but ADCs containing the anthracycline doxorubicin were not clinically efficacious probably due to the low drug potency and inadequate linker technology. The anthracycline analogue PNU-159682 is thousands of times more cytotoxic than doxorubicin, so we used it to develop a new class of ADCs. We used the same MC-vc-PAB linker and antibody in pinatuzumab vedotin but replaced the MMAE with a derivative of PNU-159682 to make anti-CD22-NMS249 and tested it for in vivo efficacy in xenograft tumors resistant to MMAE-based ADCs.Results: We derived cell lines from in vivo xenograft tumors that were made resistant to anti-CD22-vc-MMAE and anti-CD79b-vc-MMAE. We identified P-gp (ABCB1/MDR1) as the major driver of resistance to the vc-MMAE-based conjugates. Anti-CD22-NMS249 was at least as effective as anti-CD22-vc-MMAE in xenograft models of the parental cell lines and maintained its efficacy in the resistant cell lines.Conclusions: These studies provide proof of concept for an anthracycline-based ADC that could be used to treat B-cell malignancies that are resistant to vc-MMAE conjugates.
Polo-like kinase 1 (PLK1) is a serine/threonine protein kinase considered to be the master player of cell-cycle regulation during mitosis. It is indeed involved in centrosome maturation, bipolar spindle formation, chromosome separation, and cytokinesis. PLK1 is overexpressed in a variety of human tumors and its overexpression often correlates with poor prognosis. Although five different PLKs are described in humans, depletion or inhibition of kinase activity of PLK1 is sufficient to induce cell-cycle arrest and apoptosis in cancer cell lines and in xenograft tumor models. NMS-P937 is a novel, orally available PLK1-specific inhibitor. The compound shows high potency in proliferation assays having low nanomolar activity on a large number of cell lines, both from solid and hematologic tumors. NMS-P937 potently causes a mitotic cell-cycle arrest followed by apoptosis in cancer cell lines and inhibits xenograft tumor growth with clear PLK1-related mechanism of action at well-tolerated doses in mice after oral administration. In addition, NMS-P937 shows potential for combination in clinical settings with approved cytotoxic drugs, causing tumor regression in HT29 human colon adenocarcinoma xenografts upon combination with irinotecan and prolonged survival of animals in a disseminated model of acute myelogenous leukemia in combination with cytarabine. NMS-P937, with its favorable pharmacologic parameters, good oral bioavailability in rodent and nonrodent species, and proven antitumor activity in different preclinical models using a variety of dosing regimens, potentially provides a high degree of flexibility in dosing schedules and warrants investigation in clinical settings.
Background. Due to its rarity, male breastcancer (mBC) remains an inadequately characterized disease, and current evidence for treatment derives from female breast cancer (FBC). Methods. We retrospectively analyzed the clinicopathological characteristics, treatment patterns, and outcomes of mBCs treated from 2000 to 2013.Results. From a total of 97 patients with mBC, 6 (6.2%) with ductal in situ carcinoma were excluded, and 91 patients with invasive carcinoma were analyzed. Median age was 65 years (range: 25-87 years). Estrogen receptors were positive in 88 patients (96.7%), and progesterone receptors were positive in 84 patients (92.3%). HER-2 was overexpressed in 13 of 85 patients (16%). Median follow-up was 51.5 months (range: 0.5-219.3 months). Five-year progression-free survival (PFS)
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