Phase I Study of SYNB1891, an Engineered E. coli Nissle Strain Expressing STING Agonist, with and without Atezolizumab in Advanced Malignancies.

PURPOSE: SYNB1891 is a live, modified strain of the probiotic Escherichia coli Nissle 1917 (EcN) engineered to produce cyclic dinucleotides under hypoxia, leading to STimulator of INterferon Genes (STING) activation in phagocytic antigen-presenting cells in tumors and activating complementary innate immune pathways. PATIENTS AND METHODS: This first-in-human study (NCT04167137) enrolled participants with refractory advanced cancers to receive repeat intratumoral injections of SYNB1891 either alone or in combination with atezolizumab, with the primary objective of evaluating the safety and tolerability of both regimens. RESULTS: Twenty-four participants received monotherapy across six cohorts, and 8 participants received combination therapy in two cohorts. Five cytokine release syndrome events occurred with monotherapy, including one that met the criteria for dose-limiting toxicity at the highest dose; no other SYNB1891-related serious adverse events occurred, and no SYNB1891-related infections were observed. SYNB1891 was not detected in the blood at 6 or 24 hours after the first intratumoral dose or in tumor tissue 7 days following the first dose. Treatment with SYNB1891 resulted in activation of the STING pathway and target engagement as assessed by upregulation of IFN-stimulated genes, chemokines/cytokines, and T-cell response genes in core biopsies obtained predose and 7 days following the third weekly dose. In addition, a dose-related increase in serum cytokines was observed, as well as stable disease in 4 participants refractory to prior PD-1/L1 antibodies. CONCLUSIONS: Repeat intratumoral injection of SYNB1891 as monotherapy and in combination with atezolizumab was safe and well tolerated, and evidence of STING pathway target engagement was observed.

Paired 18F-Fluorodeoxyglucose (18F-FDG), and 64Cu-Copper(II)-diacetyl-bis(N(4)-methylthiosemicarbazone) (64Cu-ATSM) PET Scans in Dogs with Spontaneous Tumors and Evaluation for Hypoxia-Directed Therapy.

Hypoxia is associated with neoplastic tissue, protecting cancer cells from death by irradiation and chemotherapy. Identification of hypoxic volume of tumors could optimize patient selection for hypoxia-directed medical, immunological, and radiation therapies. Clostridium novyi-NT (CNV-NT) is an oncolytic bacterium derived from attenuated wild-type Clostridium novyi spores, which germinates exclusively in the anaerobic core of tumors with low-oxygen content. The hypothesis was that 64Cu-ATSM would localize to regions of hypoxia, and that greater hypoxic volume would result in greater germination of Clostridium novyi-NT (CNV-NT). Tumor-bearing companion dogs were recruited to a veterinary clinical trial. Dogs received a CT scan, 18F-FDG PET scan (74 MBq) and 64Cu-ATSM PET scan (74 MBq). Scan regions of interest were defined as the highest 20% of counts/voxel for each PET scan, and regions with voxels overlapping between the two scans. Maximum standardized uptake value (MaxSUV) and threshold volume were calculated. Direct oximetry was performed in select tumors. Tumor types evaluated included nerve sheath tumor (10), apocrine carcinoma (1), melanoma (3) and oral sarcoma (6). MaxSUVATSM ranged from 0.3-6.6. Measured oxygen tension ranged from 0.05-89.9 mmHg. Inverse of MaxSUVATSM had a linear relationship with oxygen tension (R2 = 0.53, P = 0.0048). Hypoxia <8 mmHg was associated with an SUVATSM > 1.0. Hypoxic volume ranged from 0 to 100% of gross tumor volume (GTV) and MaxSUVATSM was positively correlated with hypoxic volume (R = 0.674; P = 0.0001), but not GTV (P = 0.182). Tumor hypoxic volume was heterogeneous in location and distribution. 64Cu-ATSM-avid regions were associated with differential CT attenuation. Hypoxic volume did not predict CNV-NT germination. 64Cu-ATSM PET scanning predicts hypoxia patterns within spontaneously occurring tumors of dogs as measured by direct oxymetry. Total tumor volume does not accurately predict degree or proportion of tumor hypoxia.

Intratumoral Injection of Clostridium novyi-NT Spores in Patients with Treatment-refractory Advanced Solid Tumors.

PURPOSE: Intratumorally injected Clostridium novyi-NT (nontoxic; lacking the alpha toxin), an attenuated strain of C. novyi, replicates within hypoxic tumor regions resulting in tumor-confined cell lysis and inflammatory response in animals, which warrants clinical investigation. PATIENTS AND METHODS: This first-in-human study (NCT01924689) enrolled patients with injectable, treatment-refractory solid tumors to receive a single intratumoral injection of C. novyi-NT across 6 dose cohorts (1 × 104 to 3 × 106 spores, 3+3 dose-escalation design) to determine dose-limiting toxicities (DLT), and the maximum tolerated dose. RESULTS: Among 24 patients, a single intratumoral injection of C. novyi-NT led to bacterial spores germination and the resultant lysis of injected tumor masses in 10 patients (42%) across all doses. The cohort 5 dose (1 × 106 spores) was defined as the maximum tolerated dose; DLTs were grade 4 sepsis (n = 2) and grade 4 gas gangrene (n = 1), all occurring in three patients with injected tumors >8 cm. Other treatment-related grade ≥3 toxicities included pathologic fracture (n = 1), limb abscess (n = 1), soft-tissue infection (n = 1), respiratory insufficiency (n = 1), and rash (n = 1), which occurred across four patients. Of 22 evaluable patients, nine (41%) had a decrease in size of the injected tumor and 19 (86%) had stable disease as the best overall response in injected and noninjected lesions combined. C. novyi-NT injection elicited a transient systemic cytokine response and enhanced systemic tumor-specific T-cell responses. CONCLUSIONS: Single intratumoral injection of C. novyi-NT is feasible. Toxicities can be significant but manageable. Signals of antitumor activity and the host immune response support additional studies of C. novyi-NT in humans.

First-in-Class ERK1/2 Inhibitor Ulixertinib (BVD-523) in Patients with MAPK Mutant Advanced Solid Tumors: Results of a Phase I Dose-Escalation and Expansion Study.

Ulixertinib (BVD-523) is an ERK1/2 kinase inhibitor with potent preclinical activity in BRAF- and RAS-mutant cell lines. In this multicenter phase I trial (NCT01781429), 135 patients were enrolled to an accelerated 3 + 3 dose-escalation cohort and six distinct dose-expansion cohorts. Dose escalation included 27 patients, dosed from 10 to 900 mg twice daily and established the recommended phase II dose (RP2D) of 600 mg twice daily. Ulixertinib exposure was dose proportional to the RP2D, which provided near-complete inhibition of ERK activity in whole blood. In the 108-patient expansion cohort, 32% of patients required dose reduction. The most common treatment-related adverse events were diarrhea (48%), fatigue (42%), nausea (41%), and dermatitis acneiform (31%). Partial responses were seen in 3 of 18 (17%) patients dosed at or above maximum tolerated dose and in 11 of 81 (14%) evaluable patients in dose expansion. Responses occurred in patients with NRAS-, BRAF V600-, and non-V600 BRAF-mutant solid tumors.Significance: Here, we describe the first-in-human dose-escalation study of an ERK1/2 inhibitor for the treatment of patients with advanced solid tumors. Ulixertinib has an acceptable safety profile with favorable pharmacokinetics and has shown early evidence of clinical activity in NRAS- and BRAF V600- and non-V600-mutant solid-tumor malignancies. Cancer Discov; 8(2); 184-95. ©2017 AACR.See related commentary by Smalley and Smalley, p. 140This article is highlighted in the In This Issue feature, p. 127.

Multicenter, randomized phase II trial of oral CI-1033 for previously treated advanced ovarian cancer.

PURPOSE: To evaluate the antitumor activity and toxicity of two doses of CI-1033 in patients with platinum-refractory or recurrent ovarian cancer, and to determine baseline expression of epidermal growth factor receptor in tumor cells. PATIENTS AND METHODS: This phase II, open-label clinical trial evaluated CI-1033 in patients with ovarian cancer who failed prior platinum-based therapy. Two oral doses of CI-1033 were evaluated--a 50-mg and a 200--mg oral dose administered daily for 21 days in a 28-day cycle. Patients were evaluated for tumor response and toxicity; in addition, archival baseline tumor samples were analyzed by immunohistochemistry for erbB1 to erbB4 status. RESULTS: One hundred five eligible patients were treated. Baseline demographic characteristics were balanced in this heavily pretreated patient population. The median number of prior chemotherapy regimens received was four. The most commonly encountered drug-related adverse events for both dose arms were gastrointestinal (diarrhea, nausea, stomatitis) toxicity, asthenia, and rash. No responses were observed. Stable disease was confirmed in 34% and 26% of patients in the 200-mg and 50-mg arms, respectively, and 1-year survival rates were 38.5% and 37.7%, respectively. Baseline erbB3 and erbB4 revealed the highest frequencies of expression, while erbB2 was the lowest. CONCLUSION: CI-1033 did not show activity in unscreened patients with advanced ovarian cancer. At 50 mg/d, CI-1033 had a more favorable adverse events profile than at 200 mg/d. erbB3 and erbB4 receptors showed the highest expression in tumor samples while erbB2 revealed the least. There appears to be no association between baseline erbB expression and disease stability.

Phase I and pharmacodynamic study of the oral MEK inhibitor CI-1040 in patients with advanced malignancies.

PURPOSE: This phase I study was undertaken to define the toxicity, pharmacokinetics, pharmacodynamics, maximum tolerated dose (MTD), and clinical activity of CI-1040, a small-molecule inhibitor of the dual-specificity kinases MEK(mitogen-activated protein kinase kinase) -1 and MEK2 , in patients with advanced malignancy. PATIENTS AND METHODS: CI-1040 was tested in multiple daily dosing frequencies administered for 21 days repeated every 28 days leading ultimately to continuous administration, and effect of food on absorption was tested. Single dose and steady-state pharmacokinetics were assessed during cycle 1 and phosphorylated extracellular receptor kinase (pERK) levels were assessed in WBCs and also in tumor tissue from selected patients. RESULTS: Seventy-seven patients received CI-1040 at dose levels ranging from 100 mg QD to 800 mg tid. Grade 3 asthenia was dose limiting at the highest dose level tested, 800 mg tid administered with food. Ninety-eight percent of all drug-related adverse events were grade 1 or 2 in severity; most common toxicities included diarrhea, asthenia, rash, nausea, and vomiting. Plasma concentrations of CI-1040 and its active metabolite, PD 0184264, increased in a less than dose proportional manner from 100 to 800 mg QD. Administration with a high-fat meal resulted in an increase in drug exposure. The MTD and recommended phase II dose was 800 mg BID administered with food. Sixty-six patients were assessable for response. One partial response was achieved in a patient with pancreatic cancer and 19 patients (28%) achieved stable disease lasting a median of 5.5 months (range, 4 to 17 months). Inhibition of tumor pERK (median, 73%; range, 46% to 100%) was demonstrated in 10 patients. CONCLUSION: CI-1040 was well tolerated at 800 mg BID administered with food. Both target suppression and antitumor activity were demonstrated in this phase I study.

Phase II trial of intravenous CI-1042 in patients with metastatic colorectal cancer.

PURPOSE: To evaluate the antitumor activity, safety, immune response, and replication of CI-1042 (ONYX-015), an E1B 55-kd gene-deleted replication-selective adenovirus, administered intravenously to patients with metastatic colorectal cancer PATIENTS AND METHODS: Eighteen patients with metastatic colorectal cancer for whom prior chemotherapy failed were enrolled onto an open-label, multicenter, phase II study. CI-1042 was administered intravenously at a dose of 2 x 1012 viral particles every 2 weeks. Patients were evaluated for tumor response and toxicity; in addition, blood samples were taken for adenovirus DNA and neutralizing antibody analysis. RESULTS: Common toxicities included flu-like symptoms, nausea, and emesis. All 18 patients eventually were removed from study because of progressive disease. Seven patients were assessed as having stable disease after 2 months of treatment, whereas two patients were considered to have stable disease after 4 months. Detectable circulating CI-1042 DNA was identified in 36% of patients 72 hours after last infusion, which is suggestive of ongoing viral replication. CONCLUSION: In this phase II study, intravenous CI-1042 was administered safely to patients with advanced colorectal cancer. Toxicity was manageable, consisting primarily of flu-like symptoms. Stable disease was experienced by seven patients for 11 to 18 weeks.

Multicenter phase II study of the oral MEK inhibitor, CI-1040, in patients with advanced non-small-cell lung, breast, colon, and pancreatic cancer.

PURPOSE: This multicenter, open-label, phase II study was undertaken to assess the antitumor activity and safety of the oral mitogen-activated extracellular signal regulated kinase kinase (MEK) inhibitor, CI-1040, in breast cancer, colon cancer, non-small-cell lung cancer (NSCLC), and pancreatic cancer. PATIENTS AND METHODS: Patients with advanced colorectal, NSCLC, breast, or pancreatic cancer received oral CI-1040 continuously at 800 mg bid. All patients had measurable disease at baseline, a performance status of 2 or less, and adequate bone marrow, liver, and renal function. Expression of pERK, pAkt, and Ki-67 was assessed in archived tumor specimens by quantitative immunohistochemistry. RESULTS: Sixty-seven patients with breast (n = 14), colon (n = 20), NSCLC (n = 18), and pancreatic (n = 15) cancer received a total of 194 courses of treatment (median, 2.0 courses; range, one to 14 courses). No complete or partial responses were observed. Stable disease (SD) lasting a median of 4.4 months (range, 4 to 18 months) was confirmed in eight patients (one breast, two colon, two pancreas, and three NSCLC patients). Treatment was well tolerated, with 81% of patients experiencing toxicities of grade 2 or less severity. Most common toxicities included diarrhea, nausea, asthenia, and rash. A mild association (P < .055) between baseline pERK expression in archived tumor specimens and SD was observed. CONCLUSION: CI-1040 was generally well tolerated but demonstrated insufficient antitumor activity to warrant further development in the four tumors tested. PD 0325901, a second generation MEK inhibitor, has recently entered clinical development and, with significantly improved pharmacologic and pharmaceutical properties compared with CI-1040, it may better test the therapeutic potential of MEK inhibition in cancer.

Phase II study of PEND chemotherapy in patients with refractory/relapsed Hodgkin lymphoma.

High-dose chemotherapy with autologous marrow or stem cell rescue (HDC/ASCT) is an effective strategy in patients with relapsed Hodgkin lymphoma. Various chemotherapy regimens have been used for cytoreduction prior to HDC/ASCT. In this study, our objective was to determine the response rate to PEND in a group of patients with relapsed Hodgkin lymphoma. Nineteen patients with relapsed or primary refractory Hodgkin lymphoma underwent treatment with the PEND regimen and received a median of 2 cycles (1 - 6 cycles). The PEND regimen builds on our prior results with ABDIC and consists of prednisone 40 mg/m2 orally (PO) daily x 5 days; etoposide 50 mg/m2 PO daily x 14 days; mitoxantrone 5 mg/m2/d IV, days 1 and 3; and DTIC 200 mg/m2/d intravenous continuous infusion (CIV) over 24 h, days 1 to 5, via central venous catheter. The treatment was given every 28 days. There were 3 complete responses (16%) and 10 partial responses (53%) yielding a total response rate of 69% (95% C.I. 43%, 87%). Myelosuppression was the predominant toxicity; no deaths were due to toxicity. After achieving maximum response to PEND, 10 eligible patients received a consolidative treatment with HDC/ASCT. All 6 patients who did not respond to PEND died from disease progression whereas 5 of 13 responders were alive after 10 years of follow-up (3 without disease). There were 11 deaths due to disease progression; three from other causes. The initial response to PEND before subsequent ASCT consolidation treatment appears to be associated with survival. All patients who failed to achieve a response have died. We conclude that PEND is an effective treatment strategy in Hodgkin lymphoma patients previously treated with both ABVD and MOPP.

Intratumoral injection of Clostridium novyi-NT spores induces antitumor responses.

Species of Clostridium bacteria are notable for their ability to lyse tumor cells growing in hypoxic environments. We show that an attenuated strain of Clostridium novyi (C. novyi-NT) induces a microscopically precise, tumor-localized response in a rat orthotopic brain tumor model after intratumoral injection. It is well known, however, that experimental models often do not reliably predict the responses of human patients to therapeutic agents. We therefore used naturally occurring canine tumors as a translational bridge to human trials. Canine tumors are more like those of humans because they occur in animals with heterogeneous genetic backgrounds, are of host origin, and are due to spontaneous rather than engineered mutations. We found that intratumoral injection of C. novyi-NT spores was well tolerated in companion dogs bearing spontaneous solid tumors, with the most common toxicities being the expected symptoms associated with bacterial infections. Objective responses were observed in 6 of 16 dogs (37.5%), with three complete and three partial responses. On the basis of these encouraging results, we treated a human patient who had an advanced leiomyosarcoma with an intratumoral injection of C. novyi-NT spores. This treatment reduced the tumor within and surrounding the bone. Together, these results show that C. novyi-NT can precisely eradicate neoplastic tissues and suggest that further clinical trials of this agent in selected patients are warranted.

Safety biomarkers and the clinical development of oncology therapeutics: considerations for cardiovascular safety and risk management.

During the clinical development of oncology therapeutics, new safety biomarkers are being employed with broad applications and implications for risk management and regulatory approval. Clinical laboratory results, used as safety biomarkers, can influence decision making at many levels during the clinical development and regulatory review of investigational cancer therapies, including (1) initial eligibility for protocol therapy; (2) analyses used to estimate and characterize the safety profile; and (3) treatment delivery, based on specific rules to modify or discontinue protocol treatment. With the increasing applications of safety biomarkers in clinical studies, consideration must be given to possible unintended consequences, including (1) restricted access to promising treatments; (2) delays in study completion; and (3) limitations to dose delivery, escalation, and determination of the maximal tolerated dose, the recommended phase 2 dose, and the optimal biologic dose selected for registration studies. This review will compare and contrast 2 biomarkers for cardiac safety that are employed in an increasing number of clinical programs designed for investigational oncology therapeutics: (1) assessment of left ventricular ejection fraction by either echocardiography or multigated acquisition scan; and (2) electrophysiological measurement of QT/QTc duration, assessed by electrocardiogram, for predicting risk of a potentially fatal arrhythmia called torsades de pointes. While these and other new safety biomarkers have major value in the development of oncology therapeutics, their applications require careful consideration to avoid unintended consequences that could negatively affect (1) the care of patients with advanced malignancy and (2) the advancement of promising new agents.

Outcome of relapsed non-Hodgkin's lymphoma patients after allogeneic and autologous transplantation.

A retrospective review of 58 patients with non-Hodgkin's lymphoma (NHL) relapse or progression after autologous bone marrow transplantation (auto BMT), peripheral stem cell transplantation (PSCT), or allogeneic bone marrow transplantation (allo BMT) between November 1988 and December 1997 was performed. Forty-six (79%) patients had autologous transplant and 12 (21%) patients had allogeneic transplant. Median time to relapse post-transplant was 4.8 months with 49 relapses within 12 months after transplant. Overall 5-year survival was 22% (auto BMT or PSCT 25%, allo BMT 18%, p = 0.38) with a median survival of 10 months (auto BMT or PSCT 10.2 months, allo BMT 7 months, p = 0.38). Thirty-five patients received salvage therapy and, of these, 13 demonstrated objective response. The 3-year survival of responders and non-responders was 55 and 14% and median survivals were 27.8 and 8 months, respectively (p = 0.02). Interval between BMT and relapse (p = 0.0001), and response to salvage therapy (p = 0.02) were the only significant predictors of survival.