Jae K Lee

Pediatric phase I trial of oral sorafenib and topotecan in refractory or recurrent pediatric solid malignancies

Targeted kinase inhibitors and camptothecins have shown preclinical and clinical activity in several cancers. This trial evaluated the maximum tolerated dose (MTD) and dose‐limiting toxicities of sorafenib and topotecan administered orally in pediatric patients with relapsed solid tumors. Sorafenib was administered twice daily and topotecan once daily on days 1–5 and 8–12 of each 28‐day course. The study utilized a standard 3 + 3 dose escalation design. Three dose levels (DL) were evaluated: (1) sorafenib 150 mg/m2 and topotecan 1 mg/m2; (2) sorafenib 150 mg/m2 and topotecan 1.4 mg/m2; and (3) sorafenib 200 mg/m2 and topotecan 1.4 mg/m2. Pharmacokinetics were ascertained and treatment response assessed. Thirteen patients were enrolled. DL2 was the determined MTD. Grade 4 thrombocytopenia delaying therapy for >7 days was observed in one of six patients on DL2, and grade 4 neutropenia that delayed therapy in two of three patients on DL3. A patient with preexisting cardiac failure controlled with medication developed a transient drop in the left ventricular ejection fraction that improved when sorafenib was withheld. Sorafenib exposure with or without topotecan was comparable, and the concentration‐time profiles for topotecan alone and in combination with sorafenib were similar. One objective response was noted in a patient with fibromatosis. We determined MTD to be sorafenib 150 mg/m2 twice daily orally on days 1–28 combined with topotecan 1.4 mg/m2 once daily on days 1–5 and 8–12. While these doses are 1 DL below the MTD of the agents individually, pharmacokinetic studies suggested adequate drug exposure without drug interactions. The combination had limited activity in the population studied.

A phase I window, dose escalating and safety trial of metformin in combination with induction chemotherapy in relapsed refractory acute lymphoblastic leukemia: Metformin with induction chemotherapy of vincristine, dexamethasone, PEG-asparaginase, and doxorubicin

Acute lymphoblastic leukemia (ALL) remains a major cause of death in children. AMP‐activated protein kinase (AMPK) affects the unfolded protein response (UPR), leading to increased vulnerability to endoplasmic reticulum (ER) stress in ALL cells. In vitro, metformin causes ALL cell death via AMPK‐mediated inhibition of the UPR. It was evaluated whether ER stress could be induced in relapsed ALL through a phase I study investigating the safety and feasibility of metformin in combination with relapse induction chemotherapy.

Clinical Outcomes of Patients With Gastrointestinal Malignancies Participating in Phase I Clinical Trials.

Objectives: Early-phase clinical trials play a pivotal role in drug development. However, limited data are available on outcomes of gastrointestinal (GI) cancer patients enrolled in phase I clinical trials. Here, we evaluated the characteristics associated with survival in GI cancer patients participating in phase I clinical trials and attempted to validate previously established prognostic models. Materials and Methods: All consecutive patients with advanced GI tumors who participated in phase I clinical trials at our institution from January 2007 to December 2013 and received at least 1 dose of the study drug were included. Cox regression models were used to estimate multivariable-adjusted hazard ratio (HR) and 95% confidence interval. Results: In 243 study patients (median age, 62 y [range, 26 to 82 y]; 55% male), treatment included chemotherapy only (14%), targeted therapy (41%), chemotherapy+targeted therapy (42%), and others (2%) for the following disease types: pancreatic (42%), colorectal (34%), gastroesophageal (10%), hepatobiliary (13%), and others (2%). Response rate was 4%, with 38% achieving stable disease and 42% having progressive disease. Median survival was 5.8 months (range, 0.2 to 52.4 mo). Our multivariable Cox regression analyses included the following as predictors of survival: Eastern Cooperative Oncology Group performance score ≥1 (HR=1.76), prior systemic therapies ≥2 (HR=1.63), lactate dehydrogenase >618 IU/L (HR=1.85), sodium >135 mmol/L (HR=0.46), and white blood count >6×109/L (HR=1.5). Our data set was consistent with previous prognostic scores. Conclusions: This is the largest study to assess clinical outcomes in this patient population. Phase I trials provide clinical benefit to patients with advanced GI malignancies and should be recommended as a treatment option in appropriate patients.

Neurofibromin level directs RAS pathway signaling and mediates sensitivity to targeted agents in malignant peripheral nerve sheath tumors

Malignant peripheral nerve sheath tumor (MPNST) is a type of soft-tissue sarcoma strongly associated with dysfunction in neurofibromin; an inhibitor of the RAS pathway. We performed high-throughput screening of an array of FDA approved and promising agents in clinical development both alone and in combination at physiologically achievable concentrations against a panel of established MPNST cell line models. We found that drugs targeting a variety of factors in the RAS pathway can effectively lead to cell death in vitro with considerable drug combination synergy in regimens that target MEK or mTOR. We observed that the degree of relative sensitivity to chemotherapeutic agents was associated with the status of neurofibromin in these cell line models. Using a combination of agents that target MEK and mTORC1/2, we effectively silenced RAS/PI3K/MEK/mTOR signaling in vitro. Moreover, we employed RNAi against NF1 to establish that MPNST drug sensitivity is directly proportional to relative level of intracellular neurofibromin. Thus, two-drug combinations that target MEK and mTORC1/2 are most effective in halting the RAS signaling cascade, and the relative success of this and related small molecule interventions in MPNSTs may be predicated upon the molecular status of neurofibromin.

Abstract CT145: A phase I window, dose escalating and safety trial of Metformin in combination with induction chemotherapy (VPLD)in relapsed/refractory acute lymphoblastic leukemia: NCT01324180

Background: Relapsed Acute Lymphoblastic Leukemia (ALL) remains a major cause of cancer-related deaths in children. We identified the AMP activated protein kinase (AMPK) as a potential target for ALL therapy due to its regulatory effects on the unfolded protein response (UPR), leading to increased vulnerability of ALL cells to endoplasmic reticulum (ER) stress inducers. In vitro, metformin leads to ALL cell death via AMPK-mediated inhibition of the UPR. Methods: Metformin was administered twice daily continuously on a 28 day cycle in addition to the Vincristine, Dexamethasone, PEG-Asparaginase and Doxorubicin (VPLD) systemic regimen and CNS-directed therapy in pediatric patients with relapsed/refractory ALL. Metformin doses were increased in a standard 3+3 phase I design with three dose levels evaluated, 666, 1,000 and 1,333 mg/m2/day. Pharmacokinetic (PK) and pharmacodynamic (PD) evaluation of the AMPK and ER stress/UPR pathways were ascertained on days 1 and 7, and treatment response was assessed on day 29. Results: Fourteen patients were enrolled, 11 evaluable. DL3 was the maximum administered dose with 2 related DLT’s of diarrhea and acidosis. A single DLT of hypoglycemia and acidosis during an episode of sepsis was observed in DL2. Infectious SAE’s occurred in 7 patients. Two patients had posterior reversible encephalopathy syndrome; both died of disease progression within 30 days of coming off study. A single patient had stable disease, 2 had a partial response, and 3 achieved a complete response. PK studies demonstrated levels within the therapeutic range for patients with diabetes, and PD evaluation showed induction of ER stress and inhibition of the UPR. Conclusions: This trial has been completed. We found induction of ER stress with inhibition of UPR consistent with that observed in vitro leading to metformin-induced apoptosis. The chemotherapeutic backbone was tolerable and the combination with metformin yielded responses in a heavily pretreated population. Toxicities attributable to metformin occurred in all dose levels, but DLT’s were only observed in dose levels above the standard dosing for diabetes. Clinical trial information: NCT01324180 Citation Format: Matteo Trucco, Julio Barredo, John Goldberg, Gregory Hale, Jonathan Gill, Bhuvana Setty, Tiffany Smith, Jae Lee, Damon Reed. A phase I window, dose escalating and safety trial of Metformin in combination with induction chemotherapy (VPLD)in relapsed/refractory acute lymphoblastic leukemia: NCT01324180 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr CT145. doi:10.1158/1538-7445.AM2017-CT145

Abstract 1340: RAS pathway activation and sensitivity to therapeutic agents is correlated with NF1 residual activity in malignant peripheral nerve sheath tumors

Background: Malignant Peripheral Nerve Sheath Tumor (MPNST) is a malignant sarcoma that derives from a peripheral nerve or plexiform neurofibroma. Neurofibromatosis type 1 (NF-1) patients are particularly susceptible, with a higher risk, earlier onset, and worse prognosis. The major factor associated with MPNST and NF-1 is Neurofibromin 1, coded by the NF1 gene. NF1 mutation results in RAS hyperactivation. Chemotherapy for MPNST is currently limited, with poor prognosis for metastatic or unresectable tumors. Thus, the development of promising treatment solutions for MPNST to translate to clinical trials is required. Methods: Here, we seek to identify efficacious chemotherapeutic treatments for MPNST with a combination of drug screening and biological pathway analysis. We used our previously established preclinical system to test FDA approved or promising developmental agents against five cell line models for MPNST. We screened sixty agents with diverse mechanisms of action below published maximum plasma concentrations, and measured effects with a CellTiter-Glo viability assay. Promising agents were then tested in two-drug combinations, allowing for determination of synergism. We then examined the molecular effects of the top candidates with use of antibody arrays that permit detection of a series of phosphorylated proteins. Results: The group of most efficacious drugs was enriched with agents that target factors downstream of RAS, including MEK, mTOR, and PI3K inhibitors, with microtubule inhibitors, genotoxics, and HDAC inhibitors also demonstrating good results. Strong synergism was observed across our cell line models particularly in combinations containing the dual mTORC1/2 inhibitor INK128. Interestingly, drug sensitivity varied greatly between cell lines, correlating with relative NF1 protein and RAS-GTP levels. We analyzed the activation of the RAS pathway in response to drug treatment with antibody arrays and found that, following treatment, relative phosphorylation signal was more decreased compared to controls in cell lines with lower relative NF1 protein levels. Doxorubicin was able to reduce phosphorylation signal compared to controls to a level near comparable to targeted inhibitors, which could contribute to doxorubicin’s current usefulness against MPNSTs. Importantly, we identified combination treatments that were able to greatly reduce the relative phosphorylation signal of RAS pathway members versus control. Combinations containing INK128 resulted in the most pathway shutdown. These findings suggest that MPNSTs may be susceptible to combination treatments targeting RAS pathway members. Moreover, it may be possible to use pathway analysis as a diagnostic tool to predict drug tolerance. Citation Format: Elliot Kahen, Darcy Welch, Diana Yu, Christopher Cubitt, Jae Lee, Andrew Brohl, Damon R. Reed. RAS pathway activation and sensitivity to therapeutic agents is correlated with NF1 residual activity in malignant peripheral nerve sheath tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 1340. doi:10.1158/1538-7445.AM2017-1340