Ripretinib (DCC-2618) Is a Switch Control Kinase Inhibitor of a Broad Spectrum of Oncogenic and Drug-Resistant KIT and PDGFRA Variants.

Ripretinib (DCC-2618) was designed to inhibit the full spectrum of mutant KIT and PDGFRA kinases found in cancers and myeloproliferative neoplasms, particularly in gastrointestinal stromal tumors (GISTs), in which the heterogeneity of drug-resistant KIT mutations is a major challenge. Ripretinib is a "switch-control" kinase inhibitor that forces the activation loop (or activation "switch") into an inactive conformation. Ripretinib inhibits all tested KIT and PDGFRA mutants, and notably is a type II kinase inhibitor demonstrated to broadly inhibit activation loop mutations in KIT and PDGFRA, previously thought only achievable with type I inhibitors. Ripretinib shows efficacy in preclinical cancer models, and preliminary clinical data provide proof-of-concept that ripretinib inhibits a wide range of KIT mutants in patients with drug-resistant GISTs.

Determinants of the recommended phase 2 dose of molecular targeted agents.

BACKGROUND: The recommended phase 2 dose (RP2D) of anticancer agents is determined traditionally by dose-limiting toxicities. Nontoxicity or biological endpoints such as pharmacokinetics, pharmacodynamics, and efficacy can also be used to identify RP2D, which may be relevant to molecularly targeted agents (MTAs). METHODS: A systematic review identified all monotherapy phase 1 studies of MTAs in solid tumors published between 2001 and 2013. Dose, dosing schedule, and determinants of RP2D were collected from each study. A supplementary search of the US Food and Drug Administration (FDA) website identified the licensed dose for drugs with regulatory approval. Logistic regression was used to explore predictors for the RP2D being consistent with the final approved dose. RESULTS: The search identified 4175 records, of which 250 studies evaluating 181 individual MTAs were included. Of these MTAs, 161 (64%) determined an RP2D. Fifty-two trials (32%), used toxicity alone to specify an RP2D. The remaining trials used a nonclassical approach with either multiple endpoints that included toxicity (n = 87, 54%), multiple nontoxicity endpoints (n = 12, 7%), or a single nontoxicity endpoint (n = 10, 6%). Twenty-nine (16%) MTAs were approved by the FDA for solid tumor indications. The use of nonclassical definitions compared with toxicity alone was significantly associated with higher likelihood of FDA approval (odds ratio, 5.03; 95% confidence interval, 1.11-22.73; P = .036). CONCLUSIONS: In the past decade, there has been a dominance of a nonclassical approach using multiple endpoints with or without toxicity or single nontoxicity endpoints to define RPTD in MTA monotherapy phase 1 trials. Nonclassically defined RP2Ds for MTAs appear to be associated with a higher rate of FDA drug approval. Cancer 2017;123:1409-1415. © 2016 American Cancer Society.

Phase IB Study of Selinexor, a First-in-Class Inhibitor of Nuclear Export, in Patients With Advanced Refractory Bone or Soft Tissue Sarcoma.

PURPOSE: We evaluated the pharmacokinetics (PKs), pharmacodynamics, safety, and efficacy of selinexor, an oral selective inhibitor of nuclear export compound, in patients with advanced soft tissue or bone sarcoma with progressive disease. PATIENTS AND METHODS: Fifty-four patients were treated with oral selinexor twice per week (on days 1 and 3) at one of three doses (30 mg/m(2), 50 mg/m(2), or flat dose of 60 mg) either continuously or on a schedule of 3 weeks on, 1 week off. PK analysis was performed under fasting and fed states (low v high fat content) and using various formulations of selinexor (tablet, capsule, or suspension). Tumor biopsies before and during treatment were evaluated for pharmacodynamic changes. RESULTS: The most commonly reported drug-related adverse events (grade 1 or 2) were nausea, vomiting, anorexia, and fatigue, which were well managed with supportive care. Commonly reported grade 3 or 4 toxicities were fatigue, thrombocytopenia, anemia, lymphopenia, and leukopenia. Selinexor was significantly better tolerated when administered as a flat dose on an intermittent schedule. PK analysis of selinexor revealed a clinically insignificant increase (approximately 15% to 20%) in drug exposure when taken with food. Immunohistochemical analysis of paired tumor biopsies revealed increased nuclear accumulation of tumor suppressor proteins, decreased cell proliferation, increased apoptosis, and stromal deposition. Of the 52 patients evaluable for response, none experienced an objective response by RECIST (version 1.1); however, 17 (33%) showed durable (≥ 4 months) stable disease, including seven (47%) of 15 evaluable patients with dedifferentiated liposarcoma. CONCLUSION: Selinexor was well tolerated at a 60-mg flat dose on a 3-weeks-on, 1-week-off schedule. There was no clinically meaningful impact of food on PKs. Preliminary evidence of anticancer activity in sarcoma was demonstrated.

Chemotherapy for malignant germ cell ovarian cancer in adult patients with early stage, advanced and recurrent disease.

BACKGROUND: Malignant germ cell tumour of the ovary occurs in up to 0.07% of woman globally. Due to its rarity, evidence for treatment is lacking and often extrapolates clinical trial results of testicular germ cell cancers. The investigation on this rare tumour is further compounded by the fact that its occurrence in the adult population is even less compared to their paediatric counterpart. At present, the effectiveness of chemotherapy, regardless of stage in malignant germ cell tumour of the ovary is not entirely clear. OBJECTIVES: To evaluate the effectiveness and safety of chemotherapy in adult women with early stage, advanced and recurrent malignant germ cell ovarian cancers. SEARCH STRATEGY: We searched the Cochrane Central Register of Controlled Trials (CENTRAL), Issue 1, 2010, Cochrane Gynaecological Cancer Group Trials Register, MEDLINE and EMBASE up to April 2010. We also searched registers of clinical trials, abstracts of scientific meetings and reference lists of included studies. SELECTION CRITERIA: We searched for randomised controlled trials (RCTs), quasi-RCTs and non-randomised studies that compared systemic therapy in adult women diagnosed with germ cell ovarian cancer who have confirmed pathological diagnoses. DATA COLLECTION AND ANALYSIS: Two review authors independently assessed whether potentially relevant studies met the inclusion criteria, abstracted data and assessed risk of bias. MAIN RESULTS: We found one RCT and one retrospective study that met our inclusion criteria. The data from these studies were too sparse to adequately assess the effectiveness and safety of adjuvant chemotherapy in the treatment of malignant germ cell ovarian cancer. All comparisons were restricted to single study analyses and this review was only based on 32 women, so it was not adequately powered to detect differences in survival. Adverse effects of treatment and recurrence-free survival were incompletely documented and QoL was not reported in any of the studies. We did not find any studies that reported specifically on adults so there were problems in separating data on adults and children in many of the potentially relevant studies. AUTHORS' CONCLUSIONS: We found only low quality evidence on the use of chemotherapy in malignant germ cell tumours of the ovaries. Therefore we are unable to reach definite conclusions about the relative benefits and harms of chemotherapy use in this disease regardless of disease stage. Due to the benefit of chemotherapy in germ cell cancer of the testis, a trial of chemotherapy versus best supportive care is unlikely to be feasible. Despite this, good quality randomised studies are warranted in this disease to define the role of chemotherapy (type of chemotherapy, duration of treatment, benefit, short and long term toxicities). Given the rarity of this disease, we feel a trans-global approach would be essential in order to perform such trials.