Investigational New Drugs

Purpose. A phase I study of intraperitoneal paclitaxel (ip PTX) combined with gemcitabine (GEM) plus nab-paclitaxel (nab-PTX) (GnP) was conducted to determine the maximum tolerated dose (MTD) and the recommended dose (RD) in pancreatic cancer patients with peritoneal metastasis in first-line setting. Methods. Based on the 3 + 3 dose-escalation model, ip PTX, GEM and nab-PTX were administered at doses of 20 or 30 mg/m2, 800 or 1000 mg/m2 and 100 or 125 mg/m2 (level 1, 2 and 3, respectively) on days 1, 8 and 15 in 4-week cycles. Dose-limiting toxicity (DLT) defined as severe adverse events was evaluated during the first cycle of the treatment. Safety and preliminary efficacy were also investigated. Results. In total, 12 patients were enrolled. While 2 of the first 6 patients enrolled at level 1 experienced DLTs (grade 3 ip port dysfunction and grade 3 pneumonia), no DLT was observed in the next 6 patients enrolled at level 2 and 3. Therefore, we did not reach the MTD and the RD was determined to be level 3 (ip PTX of 30 mg/m2, GEM of 1000 mg/m2, and nab-PTX of 125 mg/m2). The major grade 3/4 adverse events included neutropenia (58%), anemia (33%), and ip port dysfunction (25%). The response rate was 25% and the median PFS was 5.4 (95% confidence interval; 2.4–16.0). The cytological status in peritoneal lavage turned negative in 8 patients (67%). Conclusions. Ip PTX combined with GnP was feasible and potentially effective in pancreatic cancer with peritoneal metastasis as a first-line treatment deserved further evaluations.

Low-dose metronomic chemotherapy is an emerging form of chemotherapy with distinct mechanisms of action from conventional chemotherapy (e.g., antiangiogenesis). Although developed to overcome resistance to conventional chemotherapy, metronomic chemotherapy is subject to resistance on its own. However, there is a paucity of information on mechanisms of resistance, on cross-resistance between metronomic regimens using different cytotoxic drugs, and on cross-resistance between metronomic versus conventional chemotherapy, or versus targeted antiangiogenic therapy. Herein we show that PC-3 human prostate cancer xenografts were sensitive to both metronomic cyclophosphamide and metronomic docetaxel, but resistant to metronomic topotecan. Conventional docetaxel was only moderately active in parental PC-3 and in metronomic cyclophosphamide resistant PC-3 tumors. However, in metronomic cyclophosphamide resistant PC-3 tumors combining conventional docetaxel or bolus cyclophosphamide therapy with continued metronomic cyclophosphamide was superior to each treatment alone. Furthermore, bevacizumab had single-agent activity against metronomic cyclophosphamide resistant PC-3 tumors. Microarray analyses identified altered regulation of protein translation as a potential mechanism of resistance to metronomic cyclophosphamide. Our results suggest that sensitivity to metronomic chemotherapy regimens using different cytotoxic drugs not only depends on shared mechanisms of action such as antiangiogenesis, but also on as yet unknown additional antitumor effects that appear to be drug-specific. As clinically observed with targeted antiangiogenic agents, the continued use of metronomic chemotherapy beyond progression may amplify the effects of added second-line therapies or vice versa. However, metronomic chemotherapy is no different from other systemic therapies in that predictive biomarkers will be essential to fully exploit this novel use of conventional chemotherapeutics.

Fourteen patients with advanced/recurrent squamous cell carcinoma of the uterine cervix received menogaril, 200 mg/m2 by one hour intravenous infusion at four-week intervals. No objective regressions were observed. Median time to progression was less than two months and median survival was seven months. All patients experienced neutropenia. Platelet toxicity was negligible. Venous irritation and phlebitis occurred at the infusion site in 43% of patients. Menogaril as administered in this protocol is ineffective in treating previously irradiated advanced/recurrent squamous cell carcinoma of the uterine cervix and warrants no further investigation in this disease at the dosage and administration schedule used in this protocol.

Acute lymphoblastic leukemia (ALL) is a potentially fatal disease that involves clonal expansion of early lymphoid progenitor cells. Much of drug development for ALL treatment involves targeting antigens of the clonal cell surface. Blinatumomab belongs to an emerging class of anti-cancer therapeutics referred to as bispecific T-cell engaging antibodies. The Food and Drug Administration approved its use in relapsed or refractory adult Philadelphia chromosome-negative B-cell precursor ALL in December of 2014. Blinatumomab contains both an anti-CD3 and anti-CD19 arm, allowing for the juxtaposition of CD3+ T-cells to malignant CD19+ B-cells, thereby resulting in granzyme- and perforin-mediated B-cell apoptosis. Preclinical studies suggest that blinatumomab’s efficacy is related to the effector-to-target ratio and to the difference between its affinity for CD19 and CD3. Preclinical and early phase clinical studies have allowed for the characterization of the pharmacokinetics of blinatumomab, including the determination of its short half-life. The metabolic pathway has not been fully characterized but is thought to be similar to that of other antibodies. Phase I and II studies led to the identification of an ideal stepwise dose, involving long-term continuous intravenous infusion (CIVI), to optimize its efficacy and reduce the risk of certain toxicities. A high remission rate and duration were noted among a relapsed/refractory population of patients. The results of clinical trials have identified cytokine release syndrome and neurotoxicity, among others, as serious drug-related toxicities, leading to the institution of a Risk Evaluation and Mitigation Strategy. Blinatumomab represents a significant addition to the treatment options for ALL, but it is not without its limitations, of which are its short-half life, necessitating long-term CIVI, and the eventual emergence of CD19-negative clones. Continual development of the agent involves assessing its role in the frontline setting and in combination with chemotherapy.

Introduction This phase II trial investigated chemoradiation followed by surgery and 2 years of adjuvant tetrathiomolybdate (TM) for resectable esophageal cancer. Methods Patients with resectable, locally advanced esophageal cancer received neoadjuvant cisplatin 60 mg/m2 (days 1 and 22), paclitaxel 60 mg/m2 (days 1, 8, 15, and 22), and 45 Gy hyperfractionated radiotherapy for 3 weeks followed by transhiatal esophagectomy. TM 20 mg PO QD was started 4 weeks post-op, and continued for 2 years to maintain the ceruloplasmin level between 5 and 15 mg/dl. Results Sixty-nine patients were enrolled (median age, 60 years). Sixty-six patients underwent surgery and 61 patients had a complete resection. Histologic complete response rate was 10 %. Twenty-one patients did not receive TM (metastases noted in the peri-operative period, prolonged post-operative recovery time, or patient refusal). Forty-eight patients started TM; 14 completed 24 months of treatment, 11 completed 10–18 months, 15 completed 2–8 months, and 8 completed ≤1 month. Twenty-seven patients had disease recurrence. With a median follow-up of 55 months, 25 patients were alive without disease, 1 was alive with disease, and 43 have died. Three-year recurrence-free survival was 44 % (95 % CI, 32–55 %) and the three-year overall survival was 45 % (95 % CI 33–56 %). Conclusions TM is an antiangiogenic agent that is well tolerated in the adjuvant setting. Disease-free survival and overall survival are promising when compared to historical controls treated at our institution with a similar regimen that did not include TM. However, the challenges associated with prolonged administration limit further investigation.

Piroxantrone is an anthrapyrazole compound undergoing phase II testing in a variety of diseases. The anthrapyrazoles are a series of compounds synthesized with the intent of maintaining the broad antitumor activity of anthracyclines, but with lessened cardiac toxicity. The Southwest Oncology Group (SWOG) conducted a phase II trial of piroxantrone in advanced soft tissue sarcoma. Treatment consisted of piroxantrone 150 mg/M2 administered intravenously over 1 hour every 21 days. Twenty-five eligible patients were registered to the trial. Twenty-three patients received treatment and are fully evaluable for response and toxicity. Two partial responses were seen for an overall response rate of 9% (95% confidence limit 1%–28%). Abnormal cardiac ejection fraction occurred in five patients, and fatal congestive heart failure developed in one patient on study. Toxicities other than cardiac were tolerable. Based on the observed response rate and cardiac toxicity, further trials of piroxantrone in the treatment of soft tissue sarcoma do not appear warranted.

Irofulven (MGI 114, 6-hydroxymethylacylfulvene, HMAF)is a semisynthetic illudin analog with broad in vitroanti-neoplastic activity. In this leukemia phase I study, weinvestigated the toxicity profile and activity of Irofulven inpatients with primary refractory or relapsed acute myeloid leukemia (AML), acute lymphocytic leukemia (ALL), ormyelodysplastic syndromes (MDS). Irofulven was given as anintravenous infusion over five minutes daily for five days.The starting dose was 10 mg/m2/day (50mg/m2/course). Courses were scheduled to be givenevery 3-4 weeks according to toxicity and antileukemicefficacy. Twenty patients {AML: 17 patients; MDS: onepatient; ALL: one patient; mixed lineage acute leukemia: onepatient} were treated. Nausea, vomiting, hepatic dysfunction,weakness, renal dysfunction, and pulmonary edema were doselimiting toxicities, occurring in two of five patientstreated at 20 mg/m2/day and two of three patientstreated at 12.5 mg/m2/day. The MTD was defined as10 mg/m2/day for five days. One patient withprimary resistant AML achieved complete remission. Proposedphase II studies will further define the activity of Irofulvenin patients with better prognosis AML and in otherhematological malignancies, both as a single agent and incombination regimens, particularly with topoisomerase 1inhibitors.

Tumor-selective viruses are a novel therapeutic approach for treating cancer. Tumor-Specific Immuno Gene Therapy (T-SIGn) vectors are tumor-selective adenoviral vectors designed to express immunomodulatory transgenes. Prolonged activated partial thromboplastin time (aPTT), associated with the presence of antiphospholipid antibodies (aPL), has been observed in patients with viral infections, and following administration of adenovirus-based medicines. aPL may be detected as lupus anticoagulant (LA), anti-cardiolipin (aCL) and/or anti-beta 2 glycoprotein antibodies (aβ2GPI). No subtype alone is definitive for development of clinical sequalae, however, patients who are ‘triple positive’ have a greater thrombotic risk. Additionally, isolated aCL and aβ2GPI IgM do not appear to add value in thrombotic association to aPL positivity, rather IgG subtypes must also be present to confer an increased risk. Here we report induction of prolonged aPTT and aPL in patients from eight Phase 1 studies who were treated with adenoviral vectors (n = 204). Prolonged aPTT (≥ Grade 2) was observed in 42% of patients, with a peak at 2–3 weeks post-treatment and resolution within ~ 2 months. Among patients with aPTT prolongation, LA, but not aCL IgG nor aβ2GPI IgG, was observed. The transience of the prolongation and discordance between positive LA and negative aCL/aβ2GPI IgG assays is not typical of a prothrombotic state. Among the patients with prolonged aPTT there was no evidence of an increased rate of thrombosis. These findings elucidate the relationship between viral exposure and aPL in the context of clinical trials. They suggest a framework in which hematologic changes can be monitored in patients receiving similar treatments. Clinical trial registration: NCT02028442, NCT02636036, NCT02028117, NCT03852511, NCT04053283, NCT05165433, NCT04830592, NCT05043714.