Combined immune checkpoint inhibition with durvalumab and tremelimumab with and without radiofrequency ablation in patients with advanced biliary tract carcinoma.

BACKGROUND: Current standard of care for advanced biliary tract cancer (BTC) is gemcitabine, cisplatin plus anti-PD1/PD-L1, but response rates are modest. The purpose of this study was to explore the efficacy and safety of durvalumab (anti-PD-L1) and tremelimumab (anti-CTLA-4), with and without an interventional radiology (IR) procedure in advanced BTC. METHODS: Eligible patients with advanced BTC who had received or refused at least one prior line of systemic therapy were treated with tremelimumab and durvalumab for four combined doses followed by monthly durvalumab alone with and without an IR procedure until the progression of disease or unacceptable toxicity. Objective response was assessed through CT or MRI by Response Evaluation Criteria in Solid Tumors (RECIST, version 1.1) every 8 weeks. Adverse events (AEs) were recorded and managed. The primary endpoint was 6-month progression-free survival (PFS). RESULTS: Twenty-three patients with advanced BTC were enrolled; 17 patients were assigned to treatment with durvalumab and tremelimumab (Durva/Treme); and 6 patients were treated with the combination of durvalumab, tremelimumab plus IR procedure (Durva/Treme + IR). The best clinical responses in the Durva/Treme arm were partial response (n = 1), stable disease (n = 5), progressive disease (n = 5), and in the Durva/Treme + IR arm: partial response (n = 0), stable disease (n = 3), progressive disease (n = 3). The median PFS was 2.2 months (95% CI: 1.3-3.1 months) in the Durva/Treme arm and 2.9 months (95% CI: 1.9-4.7 months) in the Durva/Treme + IR arm (p = 0.27). The median OS was 5.1 months (95% CI: 2.5-6.9 months) in the Durva/Treme arm and 5.8 months (95% CI: 2.9-40.1 months) in the Durva/Treme + IR arm (p = 0.31). The majority of AEs were grades 1-2. CONCLUSION: Durva/Treme and Durva/Treme + IR showed similar efficacy. With a manageable safety profile. Larger studies are needed to fully characterize the efficacy of Durva/Treme ± IR in advanced BTC.

VB-111 (ofranergene obadenovec) in combination with nivolumab in patients with microsatellite stable colorectal liver metastases: a single center, single arm, phase II trial.

BACKGROUND: Microsatellite stable colorectal liver metastases (MSS CLM) maintain an immunosuppressive tumor microenvironment (TME). Historically, immune-based approaches have been ineffective. VB-111 (ofranergene obadenovec) is a genetically-modified adenoviral vector targeting the TME; its unique dual mechanism induces an immune response and disrupts neovascularization. Checkpoint inhibition may synergize the immune response induced by viral-mediated anti-angiogenic gene therapy. We aimed to examine the safety and antitumor activity of VB-111 and nivolumab in patients with refractory MSS CLM and to characterize immunological treatment-response. METHODS: This was a phase II study of adult patients with histologically-confirmed MSS CLM who progressed on prior therapy. A priming dose of VB-111 1×1013 viral particles was given intravenously 2 weeks prior to starting biweekly nivolumab 240 mg and continued every 6 weeks. The combination continued until disease progression or unacceptable toxicity. The primary objectives were overall response rate and safety/tolerability. Secondary objectives included median overall survival and progression-free survival. Correlative studies were performed on paired tumor biopsies and blood. RESULTS: Between August 2020 and December 2021, 14 patients were enrolled with median age 50.5 years (40-75), and 14% were women. Median follow-up was 5.5 months. Of the 10 evaluable patients, the combination of VB-111 and nivolumab failed to demonstrate radiographic responses; at best, 2 patients had stable disease. Median overall survival was 5.5 months (95% CI: 2.3 to 10.8), and median progression-free survival was 1.8 months (95% CI: 1.4 to 1.9). The most common grade 3-4 treatment-related adverse events were fever/chills, influenza-like symptoms, and lymphopenia. No treatment-related deaths were reported. Qualitative analysis of immunohistochemical staining of paired tumor biopsies did not demonstrate significant immune infiltration after treatment, except for one patient who had exceptional survival (26.0 months). Immune analysis of peripheral blood mononuclear cells showed an increase of PD-1highKi67highCD8+ T cells and HLA-DRhigh T cells after VB-111 priming dose. Plasma cytokines interleukin-10 and tumor necrosis factor-α increased after treatment with both drugs. CONCLUSION: In patients with MSS CLM, VB-111 and nivolumab did not improve overall response rate or survival but were tolerated with minimal toxicities. While challenging to distinguish between antiviral or antitumor, correlative studies demonstrated an immune response with activation and proliferation of CD8+ T cells systemically that was poorly sustained. TRIAL REGISTRATION NUMBER: NCT04166383.

The current landscape of therapies for hepatocellular carcinoma.

Globally, primary liver cancer is the third leading cause of cancer-related deaths, with approximately 830 000 deaths worldwide in 2020, accounting for 8.3% of total deaths from all cancer types (1). This disease disproportionately affects those in countries with low or medium Human Development Index scores in Eastern Asia, South-Eastern Asia, and Northern and Western Africa (2). Hepatocellular carcinoma (HCC), the most common type of primary liver cancer, often develops in the background of chronic liver disease, caused by hepatitis B or C virus, non-alcoholic steatohepatitis (NASH), or other diseases that cause cirrhosis. Prognosis can vary dramatically based on number, size, and location of tumors. Hepatic synthetic dysfunction and performance status (PS) also impact survival. The Barcelona Clinic Liver Cancer (BCLC) staging system best accounts for these variations, providing a reliable prognostic stratification. Therapeutic considerations of this complex disease necessitate a multidisciplinary approach and can range from curative-intent surgical resection, liver transplantation or image-guided ablation to more complex liver-directed therapies like transarterial chemoembolization (TACE) and systemic therapy. Recent advances in the understanding of the tumor biology and microenvironment have brought new advances and approvals for systemic therapeutic agents, often utilizing immunotherapy or VEGF-targeted agents to modulate the immune response. This review will discuss the current landscape in the treatments available for early, intermediate, and advanced stage HCC.

Phase I/II study of PexaVec in combination with immune checkpoint inhibition in refractory metastatic colorectal cancer.

BACKGROUND: Oncolytic immunotherapy represents a unique therapeutic platform for the treatment of cancer. Here, we evaluated the safety and efficacy of the combination of pexastimogene devacirepvec (PexaVec) plus durvalumab (anti-programmed death ligand 1) with and without tremelimumab (anti-cytotoxic T-lymphocyte associated protein 4) in patients with standard chemotherapy refractory mismatch repair proficient (pMMR) metastatic colorectal cancer (mCRC) in a phase I/II trial. METHODS: Adult patients with histologically confirmed advanced pMMR mCRC, who had progressed on at least two prior lines of systemic chemotherapy were studied in four cohorts. Patients received four doses of PexaVec IV at a dose of 3×108 plaque forming units (pfu) (dose level 1) or 1×109 pfu (dose level 2) every 2 weeks. Twelve days after the first PexaVec administration, patients received either 1500 mg of durvalumab every 28 days alone or an additional single dose of 300 mg tremelimumab on day 1. Responses were assessed every 8 weeks by CT or MRI. AEs were recorded. The primary endpoints were safety and feasibility. Secondary endpoints included progression-free survival (PFS) and overall survival. Paired tumor samples and peripheral blood were collected to perform immune monitoring. RESULTS: Thirty-four patients with mCRC enrolled on to the study: 16 patients in the PexaVec/durvalumab cohorts and 18 patients in the PexaVec/durvalumab/tremelimumab cohorts. Overall, the combination of PexaVec plus immune checkpoint inhibitors did not result in any unexpected toxicities. Most common toxicities observed were fever and chills after PexaVec infusion. Two cases of grade 3 colitis, one case of a grade 2 myositis and one case of grade 3 hypotension resulted in discontinuation of immune checkpoint inhibitor and PexaVec treatment, respectively. The median PFS in the PexaVec/durvalumab/tremelimumab cohorts was 2.3 months (95% CI: 2.2 to 3.2 months) vs 2.1 months (95% CI: 1.7 to 2.8 months; p=0.57) in the PexaVec/durvalumab cohorts. Flow cytometry analysis of peripheral blood mononuclear cells revealed an increase in Ki67+CD8+ T cells on treatment. CONCLUSION: PexaVec in combination with durvalumab and tremelimumab is safe and tolerable. No unexpected toxicities were observed. The combination of PexaVec/durvalumab/tremelimumab demonstrated potential clinical activity in patients with pMMR mCRC, but further studies are needed to identify the predictive biomarkers. TRIAL REGISTRATION NUMBER: NCT03206073.

Society for Immunotherapy of Cancer (SITC) clinical practice guideline on immunotherapy for the treatment of hepatocellular carcinoma.

Patients with advanced hepatocellular carcinoma (HCC) have historically had few options and faced extremely poor prognoses if their disease progressed after standard-of-care tyrosine kinase inhibitors (TKIs). Recently, the standard of care for HCC has been transformed as a combination of the immune checkpoint inhibitor (ICI) atezolizumab plus the anti-vascular endothelial growth factor (VEGF) antibody bevacizumab was shown to offer improved overall survival in the first-line setting. Immunotherapy has demonstrated safety and efficacy in later lines of therapy as well, and ongoing trials are investigating novel combinations of ICIs and TKIs, in addition to interventions earlier in the course of disease or in combination with liver-directed therapies. Because HCC usually develops against a background of cirrhosis, immunotherapy for liver tumors is complex and oncologists need to account for both immunological and hepatological considerations when developing a treatment plan for their patients. To provide guidance to the oncology community on important concerns for the immunotherapeutic care of HCC, the Society for Immunotherapy of Cancer (SITC) convened a multidisciplinary panel of experts to develop a clinical practice guideline (CPG). The expert panel drew on the published literature as well as their clinical experience to develop recommendations for healthcare professionals on these important aspects of immunotherapeutic treatment for HCC, including diagnosis and staging, treatment planning, immune-related adverse events (irAEs), and patient quality of life (QOL) considerations. The evidence- and consensus-based recommendations in this CPG are intended to give guidance to cancer care providers treating patients with HCC.

Immune Checkpoint Blockade in Combination with Stereotactic Body Radiotherapy in Patients with Metastatic Pancreatic Ductal Adenocarcinoma.

PURPOSE: The effectiveness of immune checkpoint inhibitors (ICI) is limited in pancreatic ductal adenocarcinoma (PDAC). We conducted a phase I study to evaluate the safety of ICI with stereotactic body radiation therapy (SBRT) in patients with metastatic PDAC. PATIENTS AND METHODS: Patients enrolled must have received at least one line of prior systemic chemotherapy for metastatic disease. Cohorts A1 and A2 received durvalumab every 2 weeks plus either 8 Gy in one fraction of SBRT on day 1 or 25 Gy in five fractions on day -3 to +1. Cohorts B1 and B2 received durvalumab plus tremelimumab every 4 weeks and either 8 Gy in one fraction of SBRT on day 1 or 25 Gy in five fractions on day -3 to +1. ICIs were continued until unacceptable toxicity or disease progression. The primary objective was the safety and feasibility of treatment. Objective response was assessed in lesions not subjected to SBRT. RESULTS: Fifty-nine patients were enrolled and 39 were evaluable for efficacy. No dose-limiting toxicities were seen. The most common adverse event was lymphopenia. Two patients achieved a partial response (one confirmed and the other unconfirmed). The overall response rate was 5.1%. Median PFS and OS was 1.7 months [95% confidence intervals (CI), 0.8-2.0 months] and 3.3 months (95% CI, 1.2-6.6 months) in cohort A1; 2.5 months (95% CI, 0.1-3.7 months) and 9.0 months (95% CI, 0.5-18.4 months) in A2; 0.9 months (95% CI, 0.7-2.1 months) and 2.1 months (95% CI, 1.1-4.3 months) in B1; and 2.3 months (95% CI, 1.9-3.4 months) and 4.2 months (95% CI, 2.9-9.3 months) in B2. CONCLUSIONS: The combination of ICI and SBRT has an acceptable safety profile and demonstrates a modest treatment benefit in patients with metastatic PDAC.

A Pilot Study of the PD-1 Targeting Agent AMP-224 Used With Low-Dose Cyclophosphamide and Stereotactic Body Radiation Therapy in Patients With Metastatic Colorectal Cancer.

BACKGROUND: The prognosis of metastatic colorectal cancer (mCRC) is poor. We assessed the feasibility, safety, and efficacy of the anti-programmed cell death 1 fusion protein AMP-224 in combination with low-dose cyclophosphamide and stereotactic body radiation (SBRT) treatment in patients with mCRC refractory to standard chemotherapy. PATIENTS AND METHODS: Fifteen patients were enrolled. Six received SBRT 8 Gy on day 0 (dose level 1), whereas 9 received 8 Gy on days -2 to day 0. All received cyclophosphamide 200 mg/m2 intravenously (I.V.) on day 0. On day 1, both groups received AMP-224 10 mg/kg I.V., repeated every 2 weeks for a total of 6 doses. Primary end points were feasibility and safety. RESULTS: Ten (67%) patients completed 6 doses of AMP-224; 5 patients (33%) discontinued treatment because of disease progression. No dose-limiting toxicity was observed; 9 patients (60%) experienced treatment-related adverse events, all Grade 1 or 2. No objective response was noted; 3 patients (20%) had stable disease. Median progression-free survival and overall survival were 2.8 months (95% confidence interval [CI], 1.2-2.8 months) and 6.0 months (95% CI, 2.8-9.6 months), respectively. M2 macrophage polarization was present in the pretreatment tumor biopsy samples, but not post-treatment samples. CONCLUSION: AMP-224 in combination with SBRT and low-dose cyclophosphamide was well tolerated, however, no significant clinical benefit was observed in patients with mCRC.

Tremelimumab in Combination With Microwave Ablation in Patients With Refractory Biliary Tract Cancer.

Treatment options for patients with advanced biliary tract cancer are limited. Dysregulation of the immune system plays an important role in the pathogenesis of biliary tract cancer (BTC). This study aimed to investigate whether tremelimumab, an anti-CTLA4 (cytotoxic T-lymphocyte-associated protein 4) inhibitor, could be combined safely with microwave ablation to enhance the effect of anti-CTLA4 treatment in patients with advanced BTC. Patients were enrolled to receive monthly tremelimumab (10 mg/kg, intravenously) for six doses, followed by infusions every 3 months until off-treatment criteria were met. Thirty-six days after the first tremelimumab dose, patients underwent subtotal microwave ablation. Interval imaging studies were performed every 8 weeks. Adverse events (AEs) were noted and managed. Tumor and peripheral blood samples were collected to perform immune monitoring and whole-exome sequencing (WES). Twenty patients with refractory BTC were enrolled (median age, 56.5 years). No dose-limiting toxicities were encountered. The common treatment-related AEs included lymphopenia, diarrhea, and elevated transaminases. Among 16 patients evaluable for efficacy analysis, 2 (12.5%) patients achieved a confirmed partial response (lasting for 8.0 and 18.1 months, respectively) and 5 patients (31.3%) achieved stable disease. Median progression free survival (PFS) and overall survival (OS) were 3.4 months (95% confidence interval [CI], 2.5-5.2) and 6.0 months (95% CI, 3.8-8.8), respectively. Peripheral blood immune cell subset profiling showed increased circulating activated human leukocyte antigen, DR isotype ([HLA-DR] positive) CD8+ T cells. T-cell receptor (TCR)ß screening showed tremelimumab expanded TCR repertoire, but not reaching statistical significance (P = 0.057). Conclusion: Tremelimumab in combination with tumor ablation is a potential treatment strategy for patients with advanced BTC. Increased circulating activated CD8+ T cells and TCR repertoire expansion induced by tremelimumab may contribute to treatment benefit.