Pembrolizumab plus chemotherapy versus chemotherapy in untreated advanced pleural mesothelioma in Canada, Italy, and France: a phase 3, open-label, randomised controlled trial.

BACKGROUND: Pleural mesothelioma usually presents at an advanced, incurable stage. Chemotherapy with platinum-pemetrexed is a standard treatment. We hypothesised that the addition of pembrolizumab to platinum-pemetrexed would improve overall survival in patients with pleural mesothelioma. METHODS: We did this open-label, international, randomised phase 3 trial at 51 hospitals in Canada, Italy, and France. Eligible participants were aged 18 years or older, with previously untreated advanced pleural mesothelioma, with an Eastern Cooperative Oncology Group performance status score of 0 or 1. Patients were randomly assigned (1:1) to intravenous chemotherapy (cisplatin [75 mg/m2] or carboplatin [area under the concentration-time curve 5-6 mg/mL per min] with pemetrexed 500 mg/m2, every 3 weeks for up to 6 cycles), with or without intravenous pembrolizumab 200 mg every 3 weeks (up to 2 years). The primary endpoint was overall survival in all randomly assigned patients; safety was assessed in all randomly assigned patients who received at least one dose of study therapy. This trial is registered with ClinicalTrials.gov, NCT02784171, and is closed to accrual. FINDINGS: Between Jan 31, 2017, and Sept 4, 2020, 440 patients were enrolled and randomly assigned to chemotherapy alone (n=218) or chemotherapy with pembrolizumab (n=222). 333 (76 %) of patients were male, 347 (79%) were White, and median age was 71 years (IQR 66-75). At final analysis (database lock Dec 15, 2022), with a median follow-up of 16·2 months (IQR 8·3-27·8), overall survival was significantly longer with pembrolizumab (median overall survival 17·3 months [95% CI 14·4-21·3] with pembrolizumab vs 16·1 months [13·1-18·2] with chemotherapy alone, hazard ratio for death 0·79; 95% CI 0·64-0·98, two-sided p=0·0324). 3-year overall survival rate was 25% (95% CI 20-33%) with pembrolizumab and 17% (13-24%) with chemotherapy alone. Adverse events related to study treatment of grade 3 or 4 occurred in 60 (27%) of 222 patients in the pembrolizumab group and 32 (15%) of 211 patients in the chemotherapy alone group. Hospital admissions for serious adverse events related to one or more study drugs were reported in 40 (18%) of 222 patients in the pembrolizumab group and 12 (6%) of 211 patients in the chemotherapy alone group. Grade 5 adverse events related to one or more drugs occurred in two patients on the pembrolizumab group and one patient in the chemotherapy alone group. INTERPRETATION: In patients with advanced pleural mesothelioma, the addition of pembrolizumab to standard platinum-pemetrexed chemotherapy was tolerable and resulted in a significant improvement in overall survival. This regimen is a new treatment option for previously untreated advanced pleural mesothelioma. FUNDING: The Canadian Cancer Society and Merck & Co.

Brief Report: Canadian Cancer Trials Group IND.227: A Phase 2 Randomized Study of Pembrolizumab in Patients With Advanced Malignant Pleural Mesothelioma (NCT02784171).

Immune checkpoint inhibitors have activity in mesothelioma. IND.227 was a phase 2 trial (120 patients planned) comparing progression-free survival of standard platinum and pemetrexed (CP) versus CP + pembrolizumab (pembro) versus pembro. Accrual to the pembro arm was discontinued on the basis of interim analysis (IA-16 wk disease control rate). CP + pembro was tolerable, with progression-free survival similar between arms and median survival and overall response rate higher than those of CP alone (19.8 mo [95% confidence interval or CI: 8.4-41.36] versus 8.9 mo [95% CI: 5.3-12.8] and 47% [95% CI: 24%-71%] versus 19% [95% CI: 5%-42%], respectively). The subsequent phase 3 trial has completed accrual; results are expected in 2023.

A phase I study of vistusertib (dual mTORC1/2 inhibitor) in patients with previously treated glioblastoma multiforme: a CCTG study.

The PI3K/AKT/mTOR pathway activation plays a central role in glioblastoma multiforme (GBM) development and progression, and in resistance to anti-cancer therapies. Inhibition of the PI3K pathway has been shown to sensitize cultured glioma cells and tumor xenografts to the effects of temozolomide (TMZ) and radiation. Vistusertib is an oral inhibitor of mTORC1/2 complexes. The primary objective of this Canadian Cancer Trials Group phase I study was to determine the recommended phase II dose (RP2D) of vistusertib in patients with GBM receiving TMZ at first progression following primary treatment. Vistusertib was administered at a starting dose of 100 mg bid 2 days on/5 days off weekly with TMZ 150 mg/m2 daily for 5 days/28-days cycle. Dose escalation was according to a 3 + 3 design. Secondary objectives included assessment of vistusertib safety and toxicity profile, and preliminary efficacy. 15 patients were enrolled in the study (median age 66 (range 51-77), females 8). Vistusertib 125 mg BID in combination with TMZ 150 mg/m2 daily for 5 days was well tolerated. Vistusertib treatment-related adverse events were generally grade 1-2, with the most frequently reported being fatigue, gastrointestinal symptoms, and rash. Of 13 response evaluable patients, 1 patient (8%) had a partial response ongoing at 7.6 months of follow-up, and 5 patients had stable disease (38%) as best response (median duration 9.6 months, range 3.7-not yet reached). Six-month progression-free survival (PFS) rate was 26.6%. Combination of vistusertib with TMZ in GBM patients at first recurrence demonstrated a favorable safety profile at the tested dose levels.

Canadian Cancer Trials Group (CCTG) IND211: A randomized trial of pelareorep (Reolysin) in patients with previously treated advanced or metastatic non-small cell lung cancer receiving standard salvage therapy.

OBJECTIVES: Pelareorep (reolysin), a Dearing strain of reovirus serotype 3, has demonstrated oncolytic activity as single agent and synergy with chemotherapy. We evaluated pelareorep, combined with standard second-line chemotherapy in patients with non-small cell lung cancer (NSCLC). MATERIALS AND METHODS: This randomized phase II trial enrolled patients with advanced or metastatic NSCLC after first line chemotherapy. After a safety run-in, patients were randomized 1:1 to chemotherapy (pemetrexed [500 mg/m2, non-squamous], or docetaxel [75 mg/m2], day 1 every 21 days]) +/- pelareorep (4.5 × 1010 TCID50, days 1-3 every 21 days), stratified by EGFR mutation status. The primary outcome was progression free survival (PFS) of patients randomized to chemotherapy + pelareorep vs. chemotherapy alone. Secondary outcomes included overall survival, objective response rate and exploratory translational analyses. RESULTS: Between October 2012 and August 2015, 166 patients were enrolled (14 to the safety run in). Pelareorep did not improve the PFS vs. single agent chemotherapy (median PFS 3.0 months, 95% confidence interval [CI] 2.6-4.1) vs. 2.8 months (95% CI 2.5-4.0), hazard ratio (HR) 0.90 (95% CI 0.65-1.25), P = 0.53). Neither KRAS or EGFR mutation was associated with improved PFS, but STK11 mutations did appear to have an association with improved PFS (HR 0.29 [0.12-0.67); as did PIK3CA mutation (HR 0.45 [0.22-0.93]). The combination was tolerable, although associated with increased rates of neutropenic fever. CONCLUSION: The addition of pelareorep to second-line chemotherapy did not improve the PFS of patients with NSCLC. The three-day pelareorep schedule was tolerable. Further research is needed to evaluate the potential benefit in molecular subtypes of NSCLC.

The CDK inhibitor AT7519M in patients with relapsed or refractory chronic lymphocytic leukemia (CLL) and mantle cell lymphoma. A Phase II study of the Canadian Cancer Trials Group.

AT7519M is a small molecule inhibitor of cyclin-dependent kinases 1, 2, 4, 5, and 9 with in vitro activity against lymphoid malignancies. In two concurrent Phase II trials, we evaluated AT7519M in relapsed or refractory chronic lymphocytic leukemia (CLL) and mantle cell lymphoma (MCL) using the recommended Phase II dosing of 27 mg/m2 twice weekly for 2 of every 3 weeks. Primary objective was objective response rate (ORR). Nineteen patients were accrued (7 CLL, 12 MCL). Four CLL patients achieved stable disease (SD). Two MCL patients achieved partial response (PR), and 6 had SD. One additional MCL patient with SD subsequently achieved PR 9 months after completion of AT7519M. Tumor lysis syndrome was not reported. In conclusion, AT7519M was safely administered to patients with relapsed/refractory CLL and MCL. In CLL, some patients had tumor reductions, but the ORR was low. In MCL, activity was noted with ORR of 27%.

Phase II study of temsirolimus in women with recurrent or metastatic endometrial cancer: a trial of the NCIC Clinical Trials Group.

PURPOSE: Phosphatase and tensin homolog (PTEN) is a tumor suppressor gene, and loss of function mutations are common and appear to be important in the pathogenesis of endometrial carcinomas. Loss of PTEN causes deregulated phosphatidylinositol-3 kinase/serine-threonine kinase/mammalian target of rapamycin (PI3K/Akt/mTOR) signaling which may provide neoplastic cells with a selective survival advantage by enhancing angiogenesis, protein translation, and cell cycle progression. Temsirolimus, an ester derivative of rapamycin that inhibits mTOR, was evaluated in this setting. PATIENTS AND METHODS: Sequential phase II studies evaluated single-agent activity of temsirolimus in women with recurrent or metastatic chemotherapy-naive or chemotherapy-treated endometrial cancer. Temsirolimus 25 mg intravenously was administered weekly in 4-week cycles. RESULTS: In the chemotherapy-naive group, 33 patients received a median of four cycles (range, one to 23 cycles). Of the 29 patients evaluable for response, four (14%) had an independently confirmed partial response and 20 (69%) had stable disease as best response, with a median duration of 5.1 months (range, 3.7 to 18.4 months) and 9.7 months (range, 2.1 to 14.6 months). Only five patients (18%) had progressive disease. In the chemotherapy-treated group, 27 patients received a median of three cycles (range, one to six cycles). Of the 25 patients evaluable for response, one (4%) had an independently confirmed partial response, and 12 patients (48%) had stable disease, with a median duration of 4.3 months (range, 3.6 to 4.9 months) and 3.7 months (range, 2.4 to 23.2 months). PTEN loss (immunohistochemistry and mutational analysis) and molecular markers of PI3K/Akt/mTOR pathway did not correlate with the clinical outcome. CONCLUSION: mTOR inhibition with temsirolimus has encouraging single-agent activity in endometrial cancer which is higher in chemotherapy-naive patients than in chemotherapy-treated patients and is independent of PTEN status. The difference in activity according to prior therapy should be factored into future clinical trial designs.

A phase II study of sunitinib in patients with locally advanced or metastatic cervical carcinoma: NCIC CTG Trial IND.184.

OBJECTIVE: Vascular endothethial growth factor (VEGF) and stem cell factor (c-KIT) signaling may play a role in the development and progression of cervical carcinoma. Sunitinib malate is an oral, multi-targeted tyrosine kinase inhibitor that inhibits receptors for VEGF, c-Kit and platelet-derived growth factor. This multi-centre phase II study was performed to evaluate the activity of sunitinib in women with locally advanced or metastatic cervical carcinoma who had received up to one prior line of chemotherapy for advanced disease. METHODS: Sunitinib, 50 mg/day, was administered in 6-week cycles (4 weeks on followed by 2 weeks off treatment). The primary endpoint was the objective response rate. RESULTS: Sixteen (84%) of 19 patients enrolled had stable disease (median duration 4.4 months, 2.3-17 months), but no objective response was observed. Median time to progression was 3.5 months (range, 2.7-7.0 months). Four patients had fistulae develop on study treatment and an additional patient developed a fistula 3.5 months after discontinuation of therapy. All five patients had received either prior chemoradiation or radiation. CONCLUSIONS: A higher rate of fistula formation (26.3%) was observed than would be expected and is of concern. Sunitinib has insufficient activity as a single agent in cervical cancer to warrant further investigation.