Despite recent advances, the treatment of GI cancers remains challenging. Therapies targeting the HER family of receptors have been extensively studied in these malignancies with inconsistent results. The rationale behind varied tumor responses with these agents remains uncertain. We believe that additional studies are needed to identify biomarkers that could help identify a population of patients who would be more responsive to a given therapy.

IntroductionPheochromocytomas and sympathetic paragangliomas (PPGL) are neuroendocrine catecholamine-secreting tumors that are usually localized. Metastatic disease is rare and systemic treatment consists of conventional chemotherapy and high-specific-activity iodine-131-MIBG which was approved by the FDA in 2018. Although chemotherapy combinations still have value in specific settings, the debilitating side effects of treatment with only modest benefit have limited their use. With the introduction of a new generation of targeted therapy and immunotherapy patients with metastatic PPGL may have improved therapeutic options.Areas CoveredThe current paper presents a case of a patient with metastatic PPGL who received multiple lines of systemic treatment. Despite progression on previous single agent cabozantinib and single agent pembrolizumab on separate clinical trials, the patient has exhibited a major response to the combination of cabozantinib and nivolumab for the past 22 months. In addition, we will review the available therapies for metastatic PPGL and discuss novel agents under clinical development.ConclusionNewer targeted therapies and immunotherapy options are under clinical development with promising results for patients with PPGL.

Background: Despite the clinical success of vascular endothelial growth factor (VEGF) blockade in metastatic colorectal cancers (mCRC), resistance to anti-angiogenic drugs invariably develops. IL-8 and other cytokines have been implicated in development of resistance to anti-angiogenic therapy. Levocetirizine is a second generation H1 antihistamine with anti-inflammatory and IL-8 suppression properties. We conducted a phase II trial combining levocetirizine with capecitabine and bevacizumab to potentially overcome anti-angiogenic therapy resistance in patients with refractory mCRC. Methods: This was a single-center open-label prospective trial in refractory mCRC patients. Treatment consisted of oral capecitabine 850 mg/m 2 twice daily administered as 7 days on and 7 days off, intravenous (IV) bevacizumab 5 mg/kg every 14 days and oral levocetirizine 5 mg daily. The primary end point was progression free survival (PFS) and secondary endpoints included objective response rate (ORR) and tolerability. An exploratory endpoint included correlation of PFS with cytokine levels. A sample size of 36 evaluable patients could identify a median PFS of 3.4 months at a 0.05 significance level. To examine cytokine changes related to levocetirizine treatment, patients were randomized to Arm A where levocetirizine was started 7 days after starting chemotherapy and to Arm B where levocetirizine was started 7 days prior to chemotherapy. Cytokine levels were measured at baseline and with each cycle of chemotherapy (up to three cycles). Results: Forty-seven patients were enrolled in the trial to have 36 evaluable patients. Arm A enrolled 23 patients and Arm B enrolled 24 patients. Fifty percent of patients had progressive disease and 62% of patients had stable disease in each arm as best response. There was no demonstrable difference in PFS between the two arms (log-rank test P=0.83). Median time to progression was 3.4 months in Arm A and 3.5 months in Arm B. Conclusions: Median PFS in the trial was comparable to and appeared to be better than other regimens used in the refractory setting (e.g., median PFS of 1.9 months for regorafenib). Cytokine measurement with IL-8 levels did not show any correlation with progression free survival but patients with stable disease showed overall lower levels of IL-8 as compared to patients with progressive disease in the cytokine analysis.

763 Background: Despite clinical success of VEGF blockade in mCRC, resistance to anti-angiogenic drugs invariably develops. IL-8 and other cytokines have been implicated in resistance development to anti-angiogenic therapy. Levocetirizine is a third generation antihistamine with anti-inflammatory and IL-8 suppression properties. We conducted a phase II trial combining levocetirizine with capecitabine and bevacizumab to potentially overcome anti-angiogenic therapy resistance in patients with refractory mCRC. Methods: This was a single-center open-label prospective trial in refractory mCRC patients. Treatment consisted of oral capecitabine 850mg/m2 – 7 days on and 7 days off, IV bevacizumab 5 mg/kg every 14 days and oral levocetirizine 5 mg daily in 14 day cycles. The primary end point was PFS and secondary endpoints included ORR and tolerability. An exploratory endpoint included correlation of PFS with cytokine (IL-8 & IL-6) levels. A sample size of 36 evaluable patients could identify a median PFS of 3.4 months at a 0.05 significance level. To document cytokine changes related to levocetirizine treatment, patients were randomized to Arm A where levocetirizine was started 7 days after starting chemotherapy or to Arm B where levocetirizine was started 7 days prior to chemotherapy. For PFS determination both arms were combined for analysis. Cytokine levels were measured at baseline and with each cycle of chemotherapy (up to three cycles). Results: 43 patients were enrolled in the trial to have 36 evaluable patients. Arm A enrolled 20 patients and Arm B enrolled 23 patients. Of the patients evaluable for best response, 19 had SD and 12 had PD. Median PFS of all patients on the study was 3.4 months (ranging 0.9 to 10.6 months). Conclusions: Median PFS in the trial was comparable to and possibly better than other regimens used in the refractory setting (e.g., median PFS of 1.9 months for regorafenib). Cytokine analysis is in progress and these results and correlations with patient outcomes will be presented to assess the impact of cytokine blockade on mCRC treatment. Clinical trial information: NCT01722162.