Cytoimplant

The authors reported their first phase I trial of EUS-guided injection of allogenic mixed lymphocyte culture (cytoimplant) in patients with advanced pancreatic cancer. The strategy of cytoimplant is that cytokine production directly within a tumor can induce its regression by host antitumor effector mechanisms, and it is a well-established fact that mixed lymphocyte culture results in the release of cytokines and the activation of immune effector cells.

Eight patients with unresectable adenocarcinoma of the pancreas were enrolled to evaluate the safety and feasibility: 4 patients in stage II, 3 in stage III, and 1 in stage IV. EUS-guided single injection of cytoimplants was performed in escalating doses of 3, 6, or 9 billion cells, using a 22-guage FNA needle. After localizing the tumor on EUS, the needle was advanced through the bulk of the tumor by real-time EUS guidance. After a well was created with the needle, the needle was slowly withdrawn while the cytoimplant was simultaneously injected in a slow steady fashion. There were no procedure-related complications. There were no bone marrow, hemorrhagic, infectious, renal, cardiac, and pulmonary toxicities. There were 3 transient grade 3 gastrointestinal toxicities, and 3 patients had transient episodes of hyperbilirubinemia that were reversed by the replacement of biliary stents. Seven of 8 patients (86%) experienced low-grade fever that responded to acetaminophen, and fever was resolved within the first 4 weeks. No patient had procedure-induced pancreatitis, and toxicities were not dose related. Of the 8 patients enrolled, there were 2 patients with partial responses and 1 patient with minor response, with a median survival of 13.2 months. There was no obvious correlation between tumor response and survival. With the injection of cytoimplant and the proposed immunologic reaction, the tumor volume on imaging studies may hypothetically remain unchanged or increase despite the reduction of malignant cells. Although this was a study with a small sample size and a subsequent multicenter randomized trial of EUS-guided cytoimplant injection versus conventional chemotherapy was terminated because of negative results in the interim analysis, this phase I study first demonstrated the feasibility of EUS-FNI as a delivery method of antitumor agent.

Cytoimplant

The authors reported their first phase I trial of EUS-guided injection of allogenic mixed lymphocyte culture (cytoimplant) in patients with advanced pancreatic cancer. The strategy of cytoimplant is that cytokine production directly within a tumor can induce its regression by host antitumor effector mechanisms, and it is a well-established fact that mixed lymphocyte culture results in the release of cytokines and the activation of immune effector cells.

Eight patients with unresectable adenocarcinoma of the pancreas were enrolled to evaluate the safety and feasibility: 4 patients in stage II, 3 in stage III, and 1 in stage IV. EUS-guided single injection of cytoimplants was performed in escalating doses of 3, 6, or 9 billion cells, using a 22-guage FNA needle. After localizing the tumor on EUS, the needle was advanced through the bulk of the tumor by real-time EUS guidance. After a well was created with the needle, the needle was slowly withdrawn while the cytoimplant was simultaneously injected in a slow steady fashion. There were no procedure-related complications. There were no bone marrow, hemorrhagic, infectious, renal, cardiac, and pulmonary toxicities. There were 3 transient grade 3 gastrointestinal toxicities, and 3 patients had transient episodes of hyperbilirubinemia that were reversed by the replacement of biliary stents. Seven of 8 patients (86%) experienced low-grade fever that responded to acetaminophen, and fever was resolved within the first 4 weeks. No patient had procedure-induced pancreatitis, and toxicities were not dose related. Of the 8 patients enrolled, there were 2 patients with partial responses and 1 patient with minor response, with a median survival of 13.2 months. There was no obvious correlation between tumor response and survival. With the injection of cytoimplant and the proposed immunologic reaction, the tumor volume on imaging studies may hypothetically remain unchanged or increase despite the reduction of malignant cells. Although this was a study with a small sample size and a subsequent multicenter randomized trial of EUS-guided cytoimplant injection versus conventional chemotherapy was terminated because of negative results in the interim analysis, this phase I study first demonstrated the feasibility of EUS-FNI as a delivery method of antitumor agent.

ONYX-015

ONYX-015 (dl1520) is an E1B-55kD gene-deleted replication-selective adenovirus that preferentially replicates in and kills malignant cells. A phase I trial of injection of ONYX-015 into locally advanced pancreatic cancer was performed under CT guidance (n = 22). The treatment was well tolerated without significant virus-related toxicity. Although objective responses were not demonstrated, 6 minor responses of injected tumors were reported. However, repeated intratumoral injection of ONYX-015 under CT guidance is cumbersome. In addition, a single needle pass is insufficient for the spread of adenovirus throughout the pancreatic cancer with significant amounts of fibrosis. Subsequently, a phase I/II trial was performed under EUS guidance. The feasibility, tolerability, and efficacy of EUS injection of ONYX-015 into unresectable pancreatic carcinomas were evaluated in 21 patients. Patients underwent 8 sessions of ONYX-015 delivered by EUS injection into the primary pancreatic tumor over 8 weeks. The final 4 treatments were given in combination with gemcitabine (intravenous [IV], 1000 mg/m ² ). Patients received 2 × 10 ¹⁰ (n = 3) or 2 × 10 ¹¹ (n = 18) virus particles/treatment. No objective responses were demonstrated on day 35 after 4 injections of ONYX-015 as a single agent. After combination treatment with virus plus gemcitabine, objective partial regressions of 50% were seen in 2 patients (10%). There was no clinical pancreatitis despite mild, transient elevations in lipase levels in a minority of patients, but 2 patients had sepsis before the institution of prophylactic oral antibiotics. Two patients had duodenal perforations from the endoscope tip. No perforations occurred after the protocol was changed to transgastric injections.

TNFerade

TNFerade was constructed as a second-generation adenovector, which expresses the complementary DNA (cDNA) encoding human tumor necrosis factor (TNF). To further optimize local effectiveness and minimize systemic toxicity, the radiation-inducible immediate response early growth response (Egr) -1 promoter was placed upstream of the transcriptional start site of the human TNF cDNA. This vector was engineered to ensure that maximal gene expression and subsequent TNF secretion are constrained in space and time by radiation therapy. Human clinical trials have been performed in pancreatic, esophageal, and rectal cancers.

In patients with pancreatic cancer, long-term results of phase I/II study of EUS or percutaneous transabdominal delivery of TNFerade with chemoradiation were reported in patients with locally advanced pancreatic cancer. Five-week treatment consisted of weekly injections of 4 × 10 ⁹ , 4 × 10 ¹⁰ , 4 × 10 ¹¹ , and 1 × 10 ¹² particle units (PU) TNFerade, continuous infusion 5-FU (200 mg/m ² /d, 5 d/wk) and 50.4 Gy radiation (1.8 Gy fractions). TNFerade was delivered with a single-needle pass by percutaneous transabdominal approach whereas up to 4 injections were given by EUS ( Figs. 1–3 ). Fifty patients completed this dose-escalation study (n = 27 for EUS, n = 23 for PTA). Dose-limiting toxicities (DLTs) occurred in 3 EUS patients at 1 × 10 ¹² PU (2 patients with pancreatitis, and 1 patient with cholangitis). Major grade 3 to 4 adverse events were gastrointestinal bleeding, deep vein thrombosis (DVT), pulmonary emboli, pancreatitis, and cholangitis. The median time to tumor progression was 108 days (95% confidence interval [CI], 67–198 days) and the median overall survival (OS) was 297 days (95% CI, 201–316 days). The best median survival was seen in the 4 × 10 ¹¹ PU cohort of 332 days (95% CI, 154–316 days). Seven patients underwent surgical resection some time after treatment, and 6 had negative surgical margins. One patient had a complete pathologic response. Given the high rate of pathologically negative surgical resection after downstaging, this treatment seemed to be promising.

A 71-year-old man with T4 cancer in the neck of pancreas. Pretreatment tumor size was 27.3 × 25.9 mm on EUS.

EUS-FNI of TNFerade. The TNFerade was injected under real-time EUS guidance.

EUS at 4 weeks from EUS-FNI showed marked decrease of the tumor size (17.8 × 14.6 mm).

Subsequently, a phase II/III randomized controlled trial of SOC (chemoradiation therapy) with and without TNFerade was conducted. The authors’ single center experience of this trial demonstrated longer OS in 20 patients treated by SOC with TNFerade compared with 9 patients treated by SOC alone (14.7 vs 11.1 months, P = .022). However, the final results of this phase II/III study did not show superiority by addition of TNFerade (abstract submitted to ASCO annual meeting 2012). Median OS for TNFerade was 10.1 (95% CI, 9.1–11.7) months, compared with 10.0 (95% CI, 7.6–11.2) months for SOC. However, a subgroup analysis showed patients with T1 to T3 tumors and cancer antigen (CA) 19-9 U/mL levels less than 1000 had a longer survival with the addition of TNFerade (10.9 vs 9.0 months; P = .04). Thus, patient selection is especially important with this therapy. The most appropriate patients seem to be those with borderline resectable, locally advanced tumors.

In locally advanced esophageal cancer, a multicenter phase I dose-escalating trial of intratumoral injection of TNFerade with chemoradiotherapy was performed. Five weekly injections of TNFerade, dose-escalated logarithmically from 4 × 10 ⁸ to 4 × 10 ¹¹ PU, were given in combination with cisplatin 75 mg/m ² and 5-FU 1000 mg/m ² /day IV for 96 hours on days 1 and 29, and concurrent radiotherapy (RT) to 45Gy. Surgery was performed 9 to 15 weeks after treatment. Six patients (29%) had pathologic complete response, observed among 21 patients. Dose-limiting toxicities were not observed. The most frequent potentially related adverse events were fatigue (54%), fever (38%), nausea (29%), vomiting (21%), esophagitis (21%), and chills (21%). At the top dose of 4 × 10 ¹¹ PU, 5 out of 8 patients developed thromboembolic events. The median OS was 47.8 months. The 3- and 5-year OS and disease-free survival were 54% and 41%, and 38% and 38%, respectively. These results, especially the long-term prognosis, are encouraging and warrant further study (randomized control trial).

A pilot study of TNFerade with capecitabine and radiation therapy as neoadjuvant chemoradiation therapy was performed in 9 patients with T3, T4, or N1 rectal cancer. Patients received RT to a total dose of 50.4 to 54 Gy in combination with capecitabine 937.5 mg/m ² orally twice a day. TNFerade at a dose of 4 × 10 ¹⁰ PU was injected into the rectal tumor on the first day of RT and weekly for a total of 5 injections. Surgery was performed 5 to 10 weeks after the completion of chemoradiation. Grade 3 hematologic toxicity was observed in 2 patients. Eight patients completed all treatments. Discontinuation of treatment was necessary in 1 patient with grade 3 hematologic toxicity concurrent with ileitis. One grade 2 catheter-associated thrombosis was observed, but there were no other thrombotic events. There was no toxicity directly attributable to FNI procedure. A complete pathologic response was observed in 2 of 9 patients. This study confirmed the feasibility of EUS-FNI of antitumor agents in rectal cancer.