Alterations in the RAS signaling cascade are almost uniformly present in melanoma. RAS itself is only infrequently mutated in melanoma although downstream of RAS lie BRAF on the mitogen-activated ...protein kinase pathway and PTEN on the protein kinase B/Akt pathway. These genes are often altered in melanomas; indeed, the most frequent target of mutation in melanomas is BRAF, which is mutated in approximately 60% to 70% of superficial spreading melanomas. These mutations occur in a background that is not normal, with the CDKN2A locus also typically being mutated. We review herein the data that suggest that the distribution of the signaling mutations is important. In general, melanomas carry a mutated NRAS, a mutated BRAF, or concurrent BRAF and PTEN mutations. These data support the hypothesis that the biochemical functions of RAS are portioned by mutations in the pathways lying downstream. Moreover, these mutations have no apparent relationship to the patterns of alteration of CDKN2A and its downstream effectors. Thus, the data also suggest that successful exploitation of mutations in melanoma will be dependent on understanding not only mutations and their frequency but their genetic context as well.
Summary Background Anaplastic lymphoma kinase ( ALK ) gene rearrangements are oncogenic drivers of non-small-cell lung cancer (NSCLC). Brigatinib (AP26113) is an investigational ALK inhibitor with ...potent preclinical activity against ALK mutants resistant to crizotinib and other ALK inhibitors. We aimed to assess brigatinib in patients with advanced malignancies, particularly ALK -rearranged NSCLC. Methods In this ongoing, single-arm, open-label, phase 1/2 trial, we recruited patients from nine academic hospitals or cancer centres in the USA and Spain. Eligible patients were at least 18 years of age and had advanced malignancies, including ALK -rearranged NSCLC, and disease that was refractory to available therapies or for which no curative treatments existed. In the initial dose-escalation phase 1 stage of the trial, patients received oral brigatinib at total daily doses of 30–300 mg (according to a standard 3 + 3 design). The phase 1 primary endpoint was establishment of the recommended phase 2 dose. In the phase 2 expansion stage, we assessed three oral once-daily regimens: 90 mg, 180 mg, and 180 mg with a 7 day lead-in at 90 mg; one patient received 90 mg twice daily. We enrolled patients in phase 2 into five cohorts: ALK inhibitor-naive ALK -rearranged NSCLC (cohort 1), crizotinib-treated ALK -rearranged NSCLC (cohort 2), EGFRT790M -positive NSCLC and resistance to one previous EGFR tyrosine kinase inhibitor (cohort 3), other cancers with abnormalities in brigatinib targets (cohort 4), and crizotinib-naive or crizotinib-treated ALK -rearranged NSCLC with active, measurable, intracranial CNS metastases (cohort 5). The phase 2 primary endpoint was the proportion of patients with an objective response. Safety and activity of brigatinib were analysed in all patients in both phases of the trial who had received at least one dose of treatment. This trial is registered with ClinicalTrials.gov , number NCT01449461. Findings Between Sept 20, 2011, and July 8, 2014, we enrolled 137 patients (79 58% with ALK -rearranged NSCLC), all of whom were treated. Dose-limiting toxicities observed during dose escalation included grade 3 increased alanine aminotransferase (240 mg daily) and grade 4 dyspnoea (300 mg daily). We initially chose a dose of 180 mg once daily as the recommended phase 2 dose; however, we also assessed two additional regimens (90 mg once daily and 180 mg once daily with a 7 day lead-in at 90 mg) in the phase 2 stage. four (100% 95% CI 40–100) of four patients in cohort 1 had an objective response, 31 (74% 58–86) of 42 did in cohort 2, none (of one) did in cohort 3, three (17% 4–41) of 18 did in cohort 4, and five (83% 36–100) of six did in cohort 5. 51 (72% 60–82) of 71 patients with ALK -rearranged NSCLC with previous crizotinib treatment had an objective response (44 62% (50–73) had a confirmed objective response). All eight crizotinib-naive patients with ALK -rearranged NSCLC had a confirmed objective response (100% 63–100). Three (50% 95% CI 12–88) of six patients in cohort 5 had an intracranial response. The most common grade 3–4 treatment-emergent adverse events across all doses were increased lipase concentration (12 9% of 137), dyspnoea (eight 6%), and hypertension (seven 5%). Serious treatment-emergent adverse events (excluding neoplasm progression) reported in at least 5% of all patients were dyspnoea (ten 7%), pneumonia (nine 7%), and hypoxia (seven 5%). 16 (12%) patients died during treatment or within 31 days of the last dose of brigatinib, including eight patients who died from neoplasm progression. Interpretation Brigatinib shows promising clinical activity and has an acceptable safety profile in patients with crizotinib-treated and crizotinib-naive ALK -rearranged NSCLC. These results support its further development as a potential new treatment option for patients with advanced ALK -rearranged NSCLC. A randomised phase 2 trial in patients with crizotinib-resistant ALK -rearranged NSCLC is prospectively assessing the safety and efficacy of two regimens assessed in the phase 2 portion of this trial (90 mg once daily and 180 mg once daily with a 7 day lead-in at 90 mg). Funding ARIAD Pharmaceuticals.
Summary Background Ponatinib has shown potent activity against chronic myeloid leukaemia that is resistant to available treatment, although it is associated with arterial occlusion. We investigated ...whether this activity and safety profile would result in superior outcomes compared with imatinib in previously untreated patients with chronic myeloid leukaemia. Methods The Evaluation of Ponatinib versus Imatinib in Chronic Myeloid Leukemia (EPIC) study was a randomised, open-label, phase 3 trial designed to assess the efficacy and safety of ponatinib, compared with imatinib, in newly diagnosed patients with chronic-phase chronic myeloid leukaemia. Patients from 106 centres in 21 countries were randomly assigned (1:1, with stratification by Sokal score at diagnosis) using an interactive voice and web response system to receive oral ponatinib (45 mg) or imatinib (400 mg) once daily until progression, unacceptable toxicity, or other criteria for withdrawal were met. Eligible patients were at least 18 years of age, within 6 months of diagnosis, and Philadelphia chromosome-positive by cytogenetic assessment, with Eastern Cooperative Oncology Group performance status of 0–2, and had not previously been treated with tyrosine kinase inhibitors. The primary endpoint was major molecular response at 12 months. Patients who remained on study and had molecular assessments at specified timepoints were studied at those timepoints. Safety analyses included all treated patients, as per study protocol. This trial is registered with ClinicalTrials.gov , number NCT01650805. Findings Between Aug 14, 2012, and Oct 9, 2013, 307 patients were randomly assigned to receive ponatinib (n=155) or imatinib (n=152). The trial was terminated early, on Oct 17, 2013, following concerns about vascular adverse events observed in patients given ponatinib in other trials. Trial termination limited assessment of the primary endpoint of major molecular response at 12 months, as only 13 patients in the imatinib group and ten patients in the ponatinib group could be assessed at this timepoint; the proportion of patients achieving a major molecular response at 12 months did not differ significantly between the two groups (eight 80% of ten patients given ponatinib and five 38% of 13 patients given imatinib; p=0·074). 11 (7%) of 154 patients given ponatinib and three (2%) of 152 patients given imatinib had arterial occlusive events (p=0·052); arterial occlusive events were designated serious in ten (6%) of 154 patients given ponatinib and in one (1%) of 152 patients given imatinib (p=0·010). The data monitoring committee criterion for risk assessment (significant difference in serious grade 3 or 4 ischaemic events between groups) was not met (five 3% of 154 vs one 1% of 152; p=0·21). Grade 3 or 4 adverse events observed in more than 5% of patients in the ponatinib group were increased lipase (22 14% of 154 vs three 2% of 152 with imatinib), thrombocytopenia (19 12% of 154 vs ten 7% of 152 with imatinib), rash (ten 6% of 154 vs two 1% of 152 with imatinib). In the imatinib group, grade 3 or 4 adverse events observed in more than 5% of patients were neutropenia (12 8% of 152 vs five 3% of 154 with ponatinib) and thrombocytopenia (ten 7% of 152 vs 19 12% of 154 with ponatinib). Serious adverse events that occurred in three or more patients given ponatinib were pancreatitis (n=5), atrial fibrillation (n=3), and thrombocytopenia (n=3). No serious adverse event occurred in three or more patients given imatinib. Interpretation The efficacy of ponatinib treatment of newly diagnosed chronic-phase chronic myeloid leukaemia compared with imatinib could not be assessed due to trial termination, but preliminary data suggest there might be benefit, although with more arterial occlusive events than with imatinib at the doses studied. Because the EPIC trial was terminated early, efficacy of ponatinib in this setting remains to be established. Funding ARIAD Pharmaceuticals.
Most patients with non-small-cell lung cancer have no response to the tyrosine kinase inhibitor gefitinib, which targets the epidermal growth factor receptor (EGFR). However, about 10 percent of ...patients have a rapid and often dramatic clinical response. The molecular mechanisms underlying sensitivity to gefitinib are unknown.
We searched for mutations in the EGFR gene in primary tumors from patients with non-small-cell lung cancer who had a response to gefitinib, those who did not have a response, and those who had not been exposed to gefitinib. The functional consequences of identified mutations were evaluated after the mutant proteins were expressed in cultured cells.
Somatic mutations were identified in the tyrosine kinase domain of the EGFR gene in eight of nine patients with gefitinib-responsive lung cancer, as compared with none of the seven patients with no response (P<0.001). Mutations were either small, in-frame deletions or amino acid substitutions clustered around the ATP-binding pocket of the tyrosine kinase domain. Similar mutations were detected in tumors from 2 of 25 patients with primary non-small-cell lung cancer who had not been exposed to gefitinib (8 percent). All mutations were heterozygous, and identical mutations were observed in multiple patients, suggesting an additive specific gain of function. In vitro, EGFR mutants demonstrated enhanced tyrosine kinase activity in response to epidermal growth factor and increased sensitivity to inhibition by gefitinib.
A subgroup of patients with non-small-cell lung cancer have specific mutations in the EGFR gene, which correlate with clinical responsiveness to the tyrosine kinase inhibitor gefitinib. These mutations lead to increased growth factor signaling and confer susceptibility to the inhibitor. Screening for such mutations in lung cancers may identify patients who will have a response to gefitinib.
Resistance to tyrosine kinase inhibitors in patients with chronic myeloid leukemia (CML) and Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph-positive ALL) is frequently caused by ...mutations in the BCR-ABL kinase domain. Ponatinib (AP24534) is a potent oral tyrosine kinase inhibitor that blocks native and mutated BCR-ABL, including the gatekeeper mutant T315I, which is uniformly resistant to tyrosine kinase inhibitors.
In this phase 1 dose-escalation study, we enrolled 81 patients with resistant hematologic cancers, including 60 with CML and 5 with Ph-positive ALL. Ponatinib was administered once daily at doses ranging from 2 to 60 mg. Median follow-up was 56 weeks (range, 2 to 140).
Dose-limiting toxic effects included elevated lipase or amylase levels and pancreatitis. Common adverse events were rash, myelosuppression, and constitutional symptoms. Among Ph-positive patients, 91% had received two or more approved tyrosine kinase inhibitors, and 51% had received all three approved tyrosine kinase inhibitors. Of 43 patients with chronic-phase CML, 98% had a complete hematologic response, 72% had a major cytogenetic response, and 44% had a major molecular response. Of 12 patients who had chronic-phase CML with the T315I mutation, 100% had a complete hematologic response and 92% had a major cytogenetic response. Of 13 patients with chronic-phase CML without detectable mutations, 100% had a complete hematologic response and 62% had a major cytogenetic response. Responses among patients with chronic-phase CML were durable. Of 22 patients with accelerated-phase or blast-phase CML or Ph-positive ALL, 36% had a major hematologic response and 32% had a major cytogenetic response.
Ponatinib was highly active in heavily pretreated patients with Ph-positive leukemias with resistance to tyrosine kinase inhibitors, including patients with the BCR-ABL T315I mutation, other mutations, or no mutations. (Funded by Ariad Pharmaceuticals and others; ClinicalTrials.gov number, NCT00660920.).
For the past 40 years, various forms of interferon (IFN) have been evaluated as therapy in a number of malignant and non‐malignant diseases. With the advent of gene cloning, large quantities of pure ...IFN became available for clinical study. This paper reviews the biology, pharmacology, and clinical applications of IFN formulations most commonly used in oncology. It then reviews the most common side effects seen in patients treated with IFN, and makes recommendations for the management of IFN‐induced toxicity.
The major oncological indications for IFN include melanoma, renal cell carcinoma, AIDS‐related Kaposi's sarcoma, follicular lymphoma, hairy cell leukemia, and chronic myelogenous leukemia. Unfortunately, IFN therapy is associated with significant toxicity, which can be divided into constitutional, neuropsychiatric, hematologic, and hepatic effects. These toxicities have a major impact on the patient's quality of life, and on the physician's ability to optimally treat the patient. Careful attention to all aspects of patient care can result in improved tolerability of this difficult but promising therapy. Conclusion: a better understanding of IFN biology, indications, side effect profiles, and toxicity management will aid in optimizing its use in the treatment of patients with cancer.
Phosphatase and tensin homolog deleted in from chromosome ten (PTEN), initially also known as mutated in multiple advanced cancers or TGF-beta-regulated and epithelia cell-enriched phosphatase, is a ...tumor suppressor gene that is mutated in a large fraction of human melanomas. A broad variety of human cancers carry PTEN alterations, including glioblastomas, endometrial, breast, thyroid and prostate cancers. The PTEN protein has at least two biochemical functions: it has both lipid phosphatase and protein phosphatase activity. The lipid phosphatase activity of PTEN decreases intracellular PtdIns(3,4,5)P(3) level and downstream Akt activity. Cell-cycle progression is arrested at G1/S, mediated at least partially through the upregulation of the cyclin-dependent kinase inhibitor p27. In addition, agonist-induced apoptosis is mediated by PTEN, through the upregulation of proapoptotic machinery involving caspases and BID, and the downregulation of antiapoptotic proteins such as Bcl2. The protein phosphatase activity of PTEN is apparently less central to its involvement in tumorigenesis. It is involved in the inhibition of focal adhesion formation, cell spreading and migration, as well as the inhibition of growth factor-stimulated MAPK signaling. Therefore, the combined effects of the loss of PTEN lipid and protein phosphatase activity may result in aberrant cell growth and escape from apoptosis, as well as abnormal cell spreading and migration. In melanoma, PTEN loss has been mostly observed as a late event, although a dose-dependent loss of PTEN protein and function has been implicated in early stages of tumorigenesis as well. In addition, loss of PTEN and oncogenic activation of RAS seem to occur in a reciprocal fashion, both of which could cooperate with CDKN2A loss in contribution to melanoma tumorigenesis.
Extant evidence implicates growth factor signaling in the pathogenesis of many tumor types, including cutaneous melanoma. Recently, reciprocal activating mutations of NRAS and BRAF were found in ...benign melanocytic nevi and cutaneous melanomas. We had previously reported a similar epistatic relationship between activating NRAS mutations and inactivating PTEN/MMAC1 alterations. We thus hypothesized that BRAF and PTEN/MMAC1 mutations may cooperate to promote melanoma tumorigenesis. Overall, 40 of 47 (85%) melanoma cell lines and 11 of 16 (69%) uncultured melanoma metastases had mutations in NRAS, BRAF, or PTEN/MMAC1. NRAS was exclusively mutated in nine of 47 (19%) cell lines and two of 16 (13%) metastases, whereas BRAF was solely mutated in 28 of 47 (60%) cell lines and nine of 16 (56%) metastases. In the 12 of 15 melanoma cell lines (80%) and two of two melanoma metastases with PTEN alterations, BRAF was also mutated. These findings suggest the existence of possible cooperation between BRAF activation and PTEN loss in melanoma development.
The prognosis for women with recurrent and metastatic endometrial cancer is poor, and improved therapies are needed. The mammalian target of rapamycin (mTOR) pathway is an important target, and mTOR ...inhibitors show clinical activity in endometrial cancer.
An open-label, multicenter, randomized, phase II trial of oral ridaforolimus compared with progestin or investigator choice chemotherapy (comparator) was undertaken in women with metastatic or recurrent endometrial cancer who had progressive disease following one or two lines of chemotherapy and no hormonal therapy. The primary end point was progression-free survival (PFS) assessed by independent radiologic review.
One hundred thirty patients were enrolled (64 received ridaforolimus and 66 received the comparator), and median age was 66 years. Treatment discontinuation as a result of adverse events was 33% with ridaforolimus versus 6% with the comparator, with common (> 10%) grade 3 toxicities being hyperglycemia, anemia, and diarrhea. Thirty-eight percent (ridaforolimus) versus 71% (comparator) of patients discontinued treatment as a result of disease progression. Median PFS at the protocol prespecified interim analysis with 58 PFS events (primary end point) was 3.6 months (95% CI, 2.7 to 7.3 months) for ridaforolimus and 1.9 months (95% CI, 1.9 to 2.3 months) for the comparator (hazard ratio, 0.53; 95% CI, 0.31 to 0.90; P = .008). PFS rate for ridaforolimus versus comparator was 48% versus 18% at 16 weeks and 38% versus 15% at 24 weeks. Objective response rate for ridaforolimus versus comparator was 0% versus 4% (P = .925), and stable disease was achieved in 35% versus 17% of patients (P = .021).
Oral ridaforolimus shows encouraging activity in advanced endometrial cancer but is associated with significant toxicity. Inhibition of the PI3K/Akt/mTOR pathway may be a viable therapeutic target.
A large number of cancer-associated gene products evoke immune recognition, but host reactions rarely impede disease progression. The weak immunogenicity of nascent tumors contributes to this failure ...in host defense. Therapeutic vaccines that enhance dendritic cell presentation of cancer antigens increase specific cellular and humoral responses, thereby effectuating tumor destruction in some cases. The attenuation of T cell activation by cytotoxic T lymphocyte-associated antigen 4 (CTLA-4) further limits the potency of tumor immunity. In murine systems, the administration of antibodies that block CTLA-4 function inhibits the growth of moderately immunogenic tumors and, in combination with cancer vaccines, increases the rejection of poorly immunogenic tumors, albeit with a loss of tolerance to normal differentiation antigens. To gain a preliminary assessment of the biologic activity of antagonizing CTLA-4 function in humans, we infused a CTLA-4 blocking antibody (MDX-CTLA4) into nine previously immunized advanced cancer patients. MDX-CTLA4 stimulated extensive tumor necrosis with lymphocyte and granulocyte infiltrates in three of three metastatic melanoma patients and the reduction or stabilization of CA-125 levels in two of two metastatic ovarian carcinoma patients previously vaccinated with irradiated, autologous granulocyte-macrophage colony-stimulating factor-secreting tumor cells. MDX-CTLA4 did not elicit tumor necrosis in four of four metastatic melanoma patients previously immunized with defined melanosomal antigens. No serious toxicities directly attributable to the antibody were observed, although five of seven melanoma patients developed T cell reactivity to normal melanocytes. These findings suggest that CTLA-4 antibody blockade increases tumor immunity in some previously vaccinated cancer patients.
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