Phase II Study of BEZ235 versus Everolimus in Patients with Mammalian Target of Rapamycin Inhibitor-Naïve Advanced Pancreatic Neuroendocrine Tumors

Lessons Learned.

Treatment with BEZ235 has not been shown to demonstrate increased efficacy compared with everolimus and may be associated with a poorer tolerability profile.

The hypothesis of dual targeting of the phosphatidylinositol 3‐kinase and mammalian target of rapamycin pathways in patients with advanced pancreatic neuroendocrine tumors may warrant further study using other agents.

Background.

This phase II study investigated whether targeting the phosphatidylinositol 3‐kinase (PI3K)/mammalian target of rapamycin (mTOR) pathway via PI3K, mTOR complex 1 (mTORC1) and mTOR complex 2 (mTORC2) inhibition using BEZ235 may be more effective than mTORC1 inhibition with everolimus in patients with advanced pancreatic neuroendocrine tumors (pNET) who are naïve to mTOR inhibitor therapy.

Methods.

Patients with advanced pNET were randomized (1:1) to oral BEZ235 400 mg twice daily or oral everolimus 10 mg once daily on a continuous dosing schedule. The primary endpoint was progression‐free survival (PFS). Secondary endpoints included safety, overall response rate (ORR), overall survival (OS), and time to treatment failure.

Results.

Enrollment in this study was terminated early (62 enrolled of the 140 planned). The median PFS was 8.2 months (95% confidence interval [CI]: 5.3 to not evaluable [NE]) with BEZ235 versus 10.8 months (95% CI: 8.1–NE) with everolimus (hazard ratio 1.53; 95% CI: 0.72–3.25). The most commonly reported all‐grade adverse events (>50% of patients regardless of study treatment relationship) with BEZ235 were diarrhea (90.3%), stomatitis (74.2%), and nausea (54.8%).

Conclusion.

BEZ235 treatment in mTOR inhibitor‐naïve patients with advanced pNET did not demonstrate increased efficacy compared with everolimus and may be associated with a poorer tolerability profile.

Pan-phosphatidylinositol 3-kinase inhibition with buparlisib in patients with relapsed or refractory non-Hodgkin lymphoma

Activation of the phosphatidylinositol 3-kinase/mechanistic target of rapamycin pathway plays a role in the pathogenesis of non-Hodgkin lymphoma. This multicenter, open-label phase 2 study evaluated buparlisib (BKM120), a pan-class I phosphatidylinositol 3-kinase inhibitor, in patients with relapsed or refractory non-Hodgkin lymphoma. Three separate cohorts of patients (with diffuse large B-cell lymphoma, mantle cell lymphoma, or follicular lymphoma) received buparlisib 100 mg once daily until progression, intolerance, or withdrawal of consent. The primary endpoint was overall response rate based on a 6-month best overall response by cohort; secondary endpoints included progression-free survival, duration of response, overall survival, safety, and tolerability. Overall, 72 patients (26 with diffuse large B-cell lymphoma, 22 with mantle cell lymphoma, and 24 with follicular lymphoma) were treated. The overall response rates were 11.5%, 22.7%, and 25.0% in patients with diffuse large B-cell lymphoma, mantle cell lymphoma, and follicular lymphoma, respectively; two patients (one each with diffuse large B-cell lymphoma and mantle cell lymphoma) achieved a complete response. The most frequently reported (>20%) adverse events of any grade in the population in which safety was studied were hyperglycemia, fatigue, and nausea (36.1% each), depression (29.2%), diarrhea (27.8%), and anxiety (25.0%). The most common grade 3/4 adverse events included hyperglycemia (11.1%) and neutropenia (5.6%). Buparlisib showed activity in relapsed or refractory non-Hodgkin lymphoma, with disease stabilization and sustained tumor burden reduction in some patients, and acceptable toxicity. Development of mechanism-based combination regimens with buparlisib is warranted. (This study was funded by Novartis Pharmaceuticals Corporation and registered with ClinicalTrials.gov number, NCT01693614).

PI3K inhibitors as new cancer therapeutics: implications for clinical trial design

The PI3K–AKT–mTOR pathway is frequently activated in cancer. PI3K inhibitors, including the pan-PI3K inhibitor buparlisib (BKM120) and the PI3Kα-selective inhibitor alpelisib (BYL719), currently in clinical development by Novartis Oncology, may therefore be effective as anticancer agents. Early clinical studies with PI3K inhibitors have demonstrated preliminary antitumor activity and acceptable safety profiles. However, a number of unanswered questions regarding PI3K inhibition in cancer remain, including: what is the best approach for different tumor types, and which biomarkers will accurately identify the patient populations most likely to benefit from specific PI3K inhibitors? This review summarizes the strategies being employed by Novartis Oncology to help maximize the benefits of clinical studies with buparlisib and alpelisib, including stratification according to PI3K pathway activation status, selective enrollment/target enrichment (where patients with PI3K pathway-activated tumors are specifically recruited), nonselective enrollment with mandatory tissue collection, and enrollment of patients who have progressed on previous targeted agents, such as mTOR inhibitors or endocrine therapy. An overview of Novartis-sponsored and Novartis-supported trials that are utilizing these approaches in a range of cancer types, including breast cancer, head and neck squamous cell carcinoma, non-small cell lung carcinoma, lymphoma, and glioblastoma multiforme, is also described.

A phase II study of AMN107, a novel inhibitor of Bcr-Abl, administered to imatinib-resistant or intolerant patients (pts) with Ph+ chronic myelogenous leukemia (CML) in blast crisis (BC) or relapsed/refractory Ph+ acute lymphoblastic leukemia (ALL)

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Background: AMN107 is a highly selective, aminopyrimidine which is 30-fold more potent in vitro than imatinib and active against 32/33 imatinib resistant Bcr-Abl mutations. Methods: This open-label study evaluated safety and efficacy of AMN107 (400 mg bid) by hematologic/cytogenetic response (HR/CyR) rates in imatinib resistant/ intolerant BC or relapsed/refractory ALL pts. Results: Preliminary data from this ongoing study are presented for 18 BC and 6 ALL (5 relapsed/refractory, 1 minimal residual disease) pts. Baseline mutation data are available for 6 BC and 2 ALL pts: 2 and 1, respectively, had Bcr-Abl mutations. The overall median age was 54 yrs and the overall median exposure was 84 days. Seven patients remain on treatment (5 BC, 2 ALL) and 17 discontinued (3 adverse events, 9 progressive disease (PD), 3 deaths, 2 other). Two BC pts died of PD. 1 ALL pt had sudden cardiac death. HR was reported in 7 (38%) BC pts; 5 complete HR and 2 marrow responses/no evidence of leukemia. 3 BC pts had CyR (2 complete, 1 minor). Complete remission was reported in 2 (33%) ALL (1 relapsed/refractory and 1 MRD) pts. Adverse events in ≥ 10% were rash in 9 (37%) pts, thrombocytopenia in 8 (33%) pts (Gr 3/4 in 7 (29%), nausea in 7 (29%) pts, pyrexia in 7 (29%) pts (Gr 3/4 in 2 (8%)); vomiting in 7 (29%) pts (Gr 3/4 in 1 (4%), diarrhea, fatigue in 6 (25%) pts each, headache in 6 (25%) pts (Gr 3/4 in 1 (4%)), neutropenia in 6 (25%) pts (all Gr 3/4), anemia in 5 (21%) pts (Gr 3/4 in 4 (17%)), pain in extremity in 5 (21%) pts (Gr 3/4 in 1 (4%)), pain, peripheral edema in 4 (17%) pts each, pruritus in 4 (17%) pts (Gr 3/4 in 1 (4%)), leukocytosis in 3 (13%) pts (Gr 3/4 in 1 (4%)), arthralgia, pharyngolaryngeal pain, and upper abdominal pain 3 (13%) each. Conclusions: AMN107 has clinical activity and an acceptable safety and tolerability profile in pts with imatinib-resistant or intolerant BC and relapsed/refractory Ph+ ALL pts

[Table: see text]

A phase II study of AMN107, a novel inhibitor of Bcr-Abl, administered to imatinib-resistant or intolerant patients (pts) with chronic myelogenous leukemia (CML) in accelerated phase (AP)

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Background: AMN107 is a potent, highly selective, aminopyrimidine inhibitor which in vitro is 30-fold more potent than imatinib and is active against 32/33 imatinib resistant Bcr-Abl mutations. Methods: This open-label study was designed to evaluate the safety and efficacy of AMN107 (400 mg bid) defined by hematologic/cytogenetic response (HR/CyR) rates in imatinib resistant or intolerant AP pts. Results: Preliminary data are presented for 22 pts (77% resistant and 23% intolerant to imatinib. Treatment is ongoing for 16 (73%) pts. Median age was 62 (43–76) yrs. Median duration of AMN107 exposure was 124 (3–207) days. Median time from AP diagnosis was 6 (0.2–56) mos. Three of 5 patients with data available had a Bcr-Abl mutation at baseline. HR occurred in 14 (64%) pts of which 10 (45%) were complete, 3 (14%) were marrow responses/no evidence of leukemia, and 1 return to chronic phase. CyR occurred in 6 pts (1 each complete, partial minor, and 3 minimal). All AE’s occurring in ≥10% pts were thrombocytopenia (8 [36%] pts; Gr 3/4, 6 [27%] pts), fatigue (7 [32%]), anemia, (6 [27%]; Gr 3/4, 4 [18%] pts) pruritus, muscle spasms (6 [27%] pts each), bone pain, cough, (5 pts [23%] each) rash (5 [23%] pts; Gr 3/4, 1 [5%] pt), neutropenia (4 [18%] pts, all Gr 3/4), diarrhea, headache, myalgia, pyrexia (4 [18%] pts each), abdominal pain, chills, constipation, dyspnea, nausea, extremity pain, and peripheral edema (3 [14%] pts each). Two 2 deaths occurred, 1 pt with thrombocytopenia had a CNS bleed and 1 pt had disease progression. Conclusions: These data suggest AMN107 is clinically active and has an acceptable safety profile when administered to pts with CML-AP.

[Table: see text]

Inhibition of Hsp90 function by ansamycins causes retinoblastoma gene product-dependent G1 arrest

The ansamycin antibiotics, herbimycin A (HA) and geldanamycin (GM), bind to a conserved pocket in heat shock protein 90 (Hsp90) and alter the function of this chaperone protein. Occupancy of this pocket results in the degradation of a subset of signaling molecules. These include proteins known to associate with Hsp90, e.g., the steroid receptors and Raf, as well as certain transmembrane tyrosine kinases, such as the ErbB receptor family. In a variety of tumor cell lines, treatment with HA potently inhibited cellular proliferation by inducing G1 arrest. This arrest was accompanied by hypophosphorylation of the retinoblastoma gene product (RB) and rapid down-regulation of cyclin D- and E-associated kinase activities. Inhibition of kinase activity was found to result from loss in expression of cyclins D1, D3, and E, as well as the associated cyclin-dependent kinases, cyclin-dependent kinase 4 and cyclin-dependent kinase 6. In addition, HA treatment also caused a late induction of p27(Kip1) protein. The loss of cyclin D preceded the other effects of HA, suggesting that it might be the primary cause of G1 arrest. To determine whether the effects of HA are mediated by selective inhibition of the cyclin D-RB pathway, HA was added to tumor cell lines lacking functional RB. HA treatment of Rb-negative tumor cell lines failed to elicit a G1 arrest. In addition, after release from synchronization with nocodazole, Rb-negative but not Rb-positive cell lines were able to progress through G1 into S phase in the presence of HA. Together, these findings suggest that induction of G1 arrest by HA results from down-regulation of cyclin D expression and its associated kinase activity. Furthermore, these findings imply that Hsp90 selectively regulates signaling pathways upstream of RB.

Drug treatment of chemotherapy-induced delayed emesis

Chemotherapy-induced emesis has a major adverse impact on patients undergoing therapy for various malignancies, and this has led to considerable research in this field. Most investigative efforts have concentrated on the acute phase of emesis that occurs within the first 24 hours after chemotherapy, and significant strides forward have been made with this problem. Better control of acute emesis with newer agents such as the serotonin 5-HT3 receptor antagonists has focused increasing attention on a second phase of nausea and vomiting, known as delayed emesis, which occurs more than 24 hours after chemotherapy. This delayed phase is often not as well controlled with the antiemetics that have proven effective in acute emesis, and contributes to the distress associated with emetogenic chemotherapy. Most of the available data on delayed emesis are based on studies with cisplatin-based regimens, with much less understanding of delayed nausea and vomiting induced by non-cisplatin-based chemotherapy. Nevertheless, it is evident that the patterns of delayed emesis associated with cisplatin and non-cisplatin chemotherapy have distinct differences. The control of delayed emesis, especially following cisplatin, remains a therapeutic challenge. Contributing to the lack of progress has been the absence of an experimental model to help in elucidating the pathophysiology of delayed emesis and in the evaluation of new therapeutic approaches. The combination of metoclopramide and dexamethasone, although superior to placebo in randomised trials, provides only moderate control of delayed emesis following high-dose cisplatin. The 5-HT3 receptor antagonists that are effective in the prevention of acute emesis with cisplatin have failed to make a major impact on the delayed phase. When combined with dexamethasone, these agents provide no additional benefit to that achieved using dexamethasone alone or dexamethasone combined with metoclopramide. With non-cisplatin chemotherapy, corticosteroids and 5-HT3 receptor antagonists are the most useful agents. Efforts are ongoing to identify more effective treatments for delayed emesis. One novel approach involves the blockade of substance P binding to neurokinin-1 (NK1) receptors. This article reviews what is currently known about chemotherapy-induced delayed emesis, with a focus on treatment strategies.

Chemotherapy for recurrent disease and combined modality therapies for head and neck cancer

The identification and development of new agents and innovative treatment approaches remain a priority. The prognosis for patients with recurrent or metastatic head and neck cancer remains poor; thus participation in trials of promising investigational agents is an important option for these individuals. For patients with locally advanced tumors, combined modality treatment is undergoing rapid evolution. The optimal combination and sequence of therapies have yet to be determined. However, available data support an increasing role for chemotherapy especially as part of strategies to preserve organ function and treat unresectable disease.

Elevated viral antibody titres in spontaneous abortion

To assess the possible role of virus infections in spontaneous abortion we undertook a prospective study of three groups of patients: women who had a spontaneous abortion; women seen in the antenatal booking clinic; and those undergoing therapeutic termination of pregnancy. Venous blood was taken for antibody detection, cervical swabs for virus isolation, and in the cases of spontaneous and therapeutic abortion products of conception were sent for virus culture. The infectious agents studied were influenza A and B, adenovirus, respiratory syncytial virus, measles, psittacosis, Varicella zoster, and mumps virus. Statistical analysis revealed that women in the spontaneous abortion group has a higher incidence of antibodies against respiratory syncytial virus (P less than 0.01), and mumps virus (P less than 0.01). Among women seropositive for each virus, higher titres were found only for respiratory syncytial virus (P less than 0.05) in cases rather than controls. These results could be explained if viruses such as respiratory syncytial virus caused abortion or if women having a spontaneous abortion mount exaggerated immune responses to fetal and viral infections, and the former altered immune response is associated with spontaneous abortion.