azd-6244 and temsirolimus

Background Combinations of molecularly targeted agents may provide optimal anti-tumor activity and improve clinical outcomes for patients with advanced cancers. Selumetinib (AZD6244, ARRY-142886) is an oral, potent and highly selective, allosteric inhibitor of MEK1/2, a component of the RAS/RAF/MEK/ERK pathway which is constitutively activated in many cancers. We investigated the safety, tolerability, and pharmacokinetics (PK) of selumetinib in combination with molecularly targeted drugs erlotinib or temsirolimus in patients with advanced solid tumors. Methods Two-part study: dose escalation, to determine the maximum tolerated dose (MTD) of selumetinib in combination with erlotinib 100 mg once daily (QD) or temsirolimus 25 mg once weekly, followed by dose expansion at the respective combination MTDs to further investigate safety and anti-tumor effects. Results 48 patients received selumetinib plus erlotinib and 32 patients received selumetinib plus temsirolimus. The MTD with erlotinib 100 mg QD was selumetinib 100 mg QD, with diarrhea being dose limiting. The most common all grade adverse events (AEs): diarrhea, rash, nausea, and fatigue. Four (8.3%) patients had ≥12 weeks stable disease. The MTD with temsirolimus 25 mg once weekly was selumetinib 50 mg twice daily (BID), with mucositis and neutropenia being dose limiting. The most commonly reported AEs: nausea, fatigue, diarrhea, and mucositis. Ten (31.3%) patients had ≥12 weeks stable disease. The combination PK profiles were comparable to previously observed monotherapy profiles. Conclusions MTDs were established for selumetinib in combination with erlotinib or temsirolimus. Overlapping toxicities prevented the escalation of selumetinib to its recommended phase II monotherapy dose of 75 mg BID.. ClinicalTrials.gov NCT00600496; registered 8 July 2009.

Topics: Antineoplastic Agents; Antineoplastic Combined Chemotherapy Protocols; Benzimidazoles; Dose-Response Relationship, Drug; Erlotinib Hydrochloride; Female; Humans; Male; Maximum Tolerated Dose; Middle Aged; Neoplasms; Protein Kinase Inhibitors; Sirolimus

The MEK inhibitor, selumetinib, suppresses soft-tissue sarcoma (STS) cell proliferation in vitro. Mammalian target of rapamycin inhibitors possess modest activity against STS; however, resistance develops via MAPK pathway feedback activation. The combination of selumetinib and temsirolimus synergistically inhibits STS cell line growth. Therefore, a randomized phase II trial of selumetinib vs selumetinib plus temsirolimus was conducted.. Seventy-one adults with advanced STS who received ⩽ 2 prior chemotherapeutics were randomized to selumetinib 75 mg p.o. bid and allowed to crossover upon progression, or to selumetinib 50 mg p.o. bid plus temsirolimus 20 mg i.v. weekly, with primary endpoint of progression-free survival (PFS).. There was no difference in PFS between the two arms for the overall cohort (median 1.9 vs 2.1 months); an improved median PFS was observed in the combination arm (N = 11) over single agent (N = 10) in the prespecified leiomyosarcoma stratum (median 3.7 vs 1.8 months; P = 0.01). Four-month PFS rate was 50% (95% confidence interval 0.19-0.81) with the combination vs 0% with selumetinib alone in the leiomyosarcoma cohort. Most common grade 3/4 adverse events with the combination were mucositis (29%), lymphopenia (26%), neutropenia and anaemia (20% each).. While single-agent selumetinib has no significant activity in STS, the combination may be active for leiomyosarcomas.

Topics: Adult; Aged; Aged, 80 and over; Antineoplastic Combined Chemotherapy Protocols; Benzimidazoles; Disease-Free Survival; Drug Administration Schedule; Female; Humans; Male; Middle Aged; Sarcoma; Sirolimus; Treatment Outcome; Young Adult

KRAS-mutant lung adenocarcinomas represent the largest molecular subgroup of non-small cell lung cancers (NSCLC) and are notorious for their dismal survival perspectives. To gain more insights in etiology and therapeutic response, we focused on the tumor suppressor Protein Phosphatase 2A (PP2A) as a player in KRAS oncogenic signaling. We report that the PP2A activator PTPA (encoded by PPP2R4) is commonly affected in NSCLC by heterozygous loss and low-frequent loss-of-function mutation, and this is specifically associated with poorer overall survival of KRAS-mutant lung adenocarcinoma patients. Reduced or mutant PPP2R4 expression in A549 cells increased anchorage-independent growth in vitro and xenograft growth in vivo, correlating with increased Ki67 and c-MYC expression. Moreover, KrasG12D-induced lung tumorigenesis was significantly accelerated in Ppp2r4 gene trapped mice as compared to Ppp2r4 wild-type. A confined kinase inhibitor screen revealed that PPP2R4-depletion induced resistance against selumetinib (MEK inhibitor), but unexpectedly sensitized cells for temsirolimus (mTOR inhibitor), in vitro and in vivo. Our findings underscore a clinically relevant role for PTPA loss-of-function in KRAS-mutant NSCLC etiology and kinase inhibitor response.

Topics: A549 Cells; Adenocarcinoma of Lung; Animals; Benzimidazoles; Cell Line, Tumor; Humans; Ki-67 Antigen; Mice; Mitogen-Activated Protein Kinase Kinases; Phosphoprotein Phosphatases; Protein Kinase Inhibitors; Protein Phosphatase 2; Proto-Oncogene Proteins c-myc; Proto-Oncogene Proteins p21(ras); Sirolimus; TOR Serine-Threonine Kinases; Xenograft Model Antitumor Assays