A phase 1b study of intraperitoneal oncolytic viral immunotherapy in platinum-resistant or refractory ovarian cancer

OBJECTIVE

Our objective was to assess safety and adverse events associated with intraperitoneal Olvi-Vec virotherapy in patients with platinum-resistant or refractory ovarian cancer (PRROC). Secondary objectives included objective response rate (ORR) per RECIST 1.1 and progression-free survival (PFS).

METHODS

Olvi-Vec is a modified vaccinia virus that causes oncolysis and immune activation. An open-label phase 1b trial using a 3 + 3 dose escalation was conducted. Intraperitoneal Olvi-Vec was given as monotherapy in two consecutive daily doses. Translational analyses included anti-virus antibody levels, viral shedding, circulating tumor cells (CTCs) and T cells.

RESULTS

Twelve patients (median age: 69 years, range: 45-77) with median 5 prior therapies (range: 2-10) and 2 prior platinum lines (range: 1-5) were enrolled. There were three dose level cohorts: 3 × 10⁹ (n = 6), 1 × 10¹⁰ (n = 5), and 2.5 × 10¹⁰ (n = 1) plaque forming units (PFU)/day on two consecutive days. Treatment-related adverse events (TRAEs) included G1/G2 nausea (n = 6), fever (n = 6), abdominal distention (n = 5), and abdominal pain (n = 4). There were no Grade 4 TRAEs, no dose relationship to TRAEs, and no deaths attributed to Olvi-Vec. The ORR was 9% (1/11). Stable disease (SD) was 64% (7/11), and SD ≥15 weeks was 46% (5/11). Median PFS was 15.7 weeks (95%CI: 5.7-34.5), including extended PFS in four patients (23.2, 34.5, 59.4+ and 70.8 weeks). Three patients had extended overall survival (deceased 33.6 months, and alive with disease at 54 and 59 months). CTCs diminished in 6/8 (75%) baseline-positive patients. Immune activation was demonstrated from virus-enhanced tumor infiltration of CD8+ T-cells and activation of tumor-specific T-cells in peripheral blood.

CONCLUSIONS

Oncolytic viral therapy with intraperitoneal Olvi-Vec showed promising safety, clinical activities, and immune activation in patients with PRROC, warranting further clinical investigation.

Clinical impact of weekly paclitaxel plus cetuximab is comparable to the EXTREME regimen for recurrent/metastatic head and neck squamous cell carcinoma

BACKGROUND

Until the emergence of immune checkpoint inhibitors, the EXTREME regimen comprising platinum-based chemotherapy plus cetuximab was the standard of care for recurrent/metastatic head and neck squamous cell carcinoma (R/M HNSCC). Recent reports suggest the usefulness of regimens including taxanes in combination with cetuximab as treatment options for R/M HNSCC patients with contraindications for platinum. However, comparisons of weekly paclitaxel plus cetuximab (wPTX-Cmab) to the EXTREME regimen are limited.

MATERIALS AND METHODS

We compared the clinical impact of wPTX-Cmab to EXTREME as first line treatment for R/M HNSCC in Aichi Cancer Center Hospital. The primary outcome was overall survival (OS) and secondary outcomes were progression-free survival (PFS), overall response rate (ORR) and disease control rate (DCR). Propensity score-adjusted Cox proportional hazard models were used to determine hazard ratios (HRs) and 95% confidence intervals (CIs).

RESULTS

From 2012 to 2018, 77 patients, including 55 treated with EXTREME and 22 refractory or intolerant to platinum treated with wPTX-Cmab, were analyzed. wPTX-Cmab was comparable to EXTREME on OS [adjusted HR 0.82 (95% CI 0.39-1.48)], PFS [adjusted HR 0.90 (95% CI 0.49-1.65)], ORR [wPTX-Cmab 34.7% (12-43), EXTREME 30.9% (18-43), p = 0.877] and DCR [wPTX-Cmab 72.7% (52-92), EXTREME 65.4% (52-78), p = 0.337]. Survival trends remained similar after stratification by platinum-refractory or intolerance status. Disease control with wPTX-Cmab was significantly associated with better OS [adjusted HR 0.18 (0.05-0.57)].

CONCLUSION

wPTX-Cmab may be a suitable treatment option for R/M HNSCC patients with contraindications for platinum.

Treating Japanese Patients With Pembrolizumab for Platinum-Refractory Advanced Urothelial Carcinoma in Real-World Clinical Practice

Background

Since December 2017, pembrolizumab has been approved in Japan as a second-line treatment for radical unresectable urothelial carcinoma (UC) that has become exacerbated after chemotherapy by the international randomized phase 3 trial, KEYNOTE-045. The aim of this study was to evaluate the oncological efficacy and safety of pembrolizumab after failure of platinum-based chemotherapy in Japanese patients with advanced UC in real-world clinical practice.

Methods

A total of 34 patients who received pembrolizumab after the failure of platinum-based chemotherapy for advanced urothelial carcinoma at four institutions between January 2018 and August 2019 were retrospectively evaluated. In all patients, UC was histopathologically diagnosed, and disease progression after platinum-based chemotherapy was radiologically confirmed.

Results

The median follow-up period was 7.7 months. The objective response rate, median progression-free survival, and median overall survival were 20.6%, 3.3 months, and 11.7 months, respectively. Regarding the toxicities associated with pembrolizumab, adverse events (AEs) of any grade occurred in 61.8%, and grade 3 AEs occurred in 23.5%; grade ≥ 4 AEs did not occur in any patients. Univariate analyses revealed that the Eastern Cooperative Oncology Group Performance Status, neutrophil/lymphocyte ratio, liver metastases, and time from previous chemotherapy were prognostic variables. Multivariate analyses revealed that liver metastases (positive: hazard ratio, 4.23; 95% confidence interval, 1.48 - 12.08; P < 0.01) and time from previous chemotherapy (≥ 3 months: hazard ratio, 5.06; 95% confidence interval, 1.43 - 17.91; P = 0.01) were independent prognostic factors.

Conclusions

In this real-world clinical study, these findings concerning the efficacy and safety of pembrolizumab for advanced UC in Japanese patients were comparable to those of the open-label, international, phase 3 trial KEYNOTE-045. Liver metastases and time from previous chemotherapy were independent prognostic factors in the present study.

Pembrolizumab Combined With Either Docetaxel or Gemcitabine in Patients With Advanced or Metastatic Platinum-Refractory Urothelial Cancer: Results From a Phase I Study

INTRODUCTION

Cytotoxic chemotherapy might prime urothelial cancer (UC) to checkpoint inhibition, prompting a trial of chemotherapy with the programmed death receptor-1 inhibitor pembrolizumab.

PATIENTS AND METHODS

Patients with advanced, platinum-refractory UC received pembrolizumab and either docetaxel (arm A) or gemcitabine (arm B). Primary end points were assessments of maximum tolerated dose and dose-limiting toxicity (DLT). Secondary end points were overall response rate (ORR) and progression-free survival (PFS).

RESULTS

Twelve patients were enrolled in the initial cohorts; 6 in each arm. One DLT was seen in each arm: Grade 3 hypophosphatemia (arm A), Grade 3 diarrhea (arm B). Adverse events of Grade >3 were observed in 7 (54%), the most common being anemia (6; 50%), fatigue (6; 50%), hyponatremia (4; 33%) and neutropenia (3; 25%), with no treatment-related deaths. There were 5 confirmed responses (1 complete, 4 partial), with an ORR of 42% and disease control rate (DCR) of 58%. Arm A had an ORR of 50% and DCR of 67%, whereas arm B had an ORR of 33% and DCR of 50%. Median PFS was 4.8, 5.7, and 3.7 months for the overall cohort, arm A, and arm B, respectively.

CONCLUSION

Pembrolizumab with either docetaxel or gemcitabine is feasible for treatment of platinum-refractory advanced UC patients. Preliminary efficacy was observed. Further examination is warranted.

Emerging Role of Immunotherapy in Advanced Urothelial Carcinoma

PURPOSE OF REVIEW

Advanced urothelial carcinoma (aUC) has long been treated preferably with cisplatin-based chemotherapy, but many patients are cisplatin-ineligible whereas for those who progress on a platinum-based regimen treatment options are limited. We review key recent data regarding immune checkpoint inhibitors that are changing this treatment landscape.

RECENT FINDINGS

Since May 2016, five different agents targeting the PD-1/PD-L1 pathway (atezolizumab, pembrolizumab, nivolumab, avelumab, durvalumab) have received FDA approval for the treatment of aUC in the platinum-refractory setting, while pembrolizumab and atezolizumab are FDA-approved for cisplatin-ineligible patients in the first-line setting. Clinical outcomes and safety profiles of these agents appear relatively comparable across separate trials; however, only pembrolizumab is supported by level I evidence from a large randomized phase III trial showing overall survival benefit over conventional cytotoxic salvage chemotherapy in the platinum-refractory setting. Pembrolizumab has the highest level of evidence in platinum-refractory aUC, whereas pembrolizumab and atezolizumab have comparable level of evidence in the frontline setting in cisplatin-ineligible patients. Ongoing research is evaluating novel agents, various rational combinations, and sequences, as well as predictive and prognostic biomarkers.

A multicenter, open-label, expanded phase 2 study to evaluate the safety and efficacy of etirinotecan pegol, a polymer conjugate of irinotecan, in women with recurrent platinum-resistant or refractory ovarian cancer

OBJECTIVE

Etirinotecan pegol (EP) is a novel polyethylene glycol conjugated form of irinotecan with documented activity in platinum-resistant ovarian cancer (PROC). We report the results of the expanded portion of a phase II study of EP in patients with PROC who received prior pegylated liposomal doxorubicin (PLD) or who were unable to receive it.

METHODS

This multicenter, open-label, phase II study evaluated EP q21d for PROC. The primary endpoint was objective response rate (ORR) by Response Evaluation Criteria in Solid Tumors version 1.0. Secondary endpoints included progression-free survival (PFS), overall survival (OS), and safety. Patient populations evaluated included a modified intent-to-treat (mITT) group consisting of all patients who received at least one dose and with measurable disease and a primary efficacy (pEFF) group (subset of the mITT population who received prior PLD).

RESULTS

One hundred thirty-nine patients were enrolled. Of the 132 patients in the mITT group, 20 achieved an ORR (15.2%; 95% CI 9.5-22.4); median PFS and OS were 4.4 months and 10.2 months, respectively. In the pEFF group (n=104), 15 patients (14.4%; 95% CI 8.3-22.7) achieved an ORR; median PFS and OS were 4.4 months and 10.9 months, respectively. The most common grade 3/4 toxicities were diarrhea (20%), abdominal pain (17%), vomiting (14%), dehydration (13%), and nausea (13%). Severe diarrhea was reduced to 15% with strict adherence to screening and management guidelines.

CONCLUSIONS

This study confirms the activity and safety of single-agent EP in patients with PROC, including patients who received prior PLD. Further evaluation earlier in the disease course and in combination is warranted.

Bringing new medicines to women with epithelial ovarian cancer: what is the unmet medical need?

Background

Therapy for advanced epithelial ovarian cancer (OC) includes first line platinum/taxane-containing chemotherapy and re-treatment with platinum-containing regimens for disease recurrence in patients likely to respond again. Single-agent, non-platinum, cytotoxic agents are commonly used to treat patients resistant to platinum retreatment, but these agents are associated with dose-limiting toxicities and response rates below 20%.

Main body

Recent advances have led to novel targeted treatments for recurrent OC that offer opportunities to improve response rates and prolong progression-free intervals. However, they also add complexity to the process of selecting treatment for individual patients at different stages of the disease process. Advanced and recurrent OC is rarely cured. Multiple lines of platinum combinations, and nonplatinum chemotherapeutics eventually fail to achieve clinical benefit, thus other active and tolerable systemic therapies are needed. Consequently, the US Food and Drug Administration has created a mechanism for “accelerated approval” of new medicines in situations of high unmet medical need.

Conclusion

We review the clinical implications of recent key clinical studies in these settings and outline the path forward for study design and approval of novel therapeutics to treat recurrent OC.

Platinum-refractory germ cell tumors: an update on current treatment options and developments

PURPOSE

In general, 50 % up to 80 % of metastasized germ cell tumor patients can be cured by platinum-based chemotherapy. However, 3-5 % of patients will still die of platinum-refractory disease and new systemic treatment options are needed to improve treatment success in this difficult setting. This review aims to give an overview on treatment options and current developments in the field of platinum-refractory male germ cell tumors.

METHODS

A comprehensive literature search was conducted searching PubMed, Medline, Cochrane and Embase to identify clinical trials regarding the treatment of platinum-refractory disease. ASCO, EAU and ESMO conference proceedings were searched to identify unpublished results of relevant trials. Comprehensive review papers were hand searched for additional references. Clinicaltrials.gov was checked for ongoing clinical trials in the field of platinum-refractory germ cell tumors.

RESULTS

Outcome of platinum-refractory disease remains poor. Single-agents with reasonable activity are gemcitabine, oxaliplatin and paclitaxel, but complete remissions resulting in long-term survival could not be achieved. The triple-combination of gemcitabine, oxaliplatin and paclitaxel followed by resection of residual masses provides the best outcomes with objective responses in 51 % of patients and long-term survival in approximately 10-15 %. To date, no molecularly targeted agent has shown reasonable activity.

CONCLUSIONS

Treatment options for platinum-refractory disease are limited, but a small subset of patients may achieve long-term disease-free survival by multimodal treatment. The potential of novel targeted agents, i.e. by immune-checkpoint-inhibition remains to be defined.