Durable Responses in Patients With Advanced Cholangiocarcinoma on Sequential Dual-agent Immunotherapy After Progressing on Single-agent Immunotherapy.

OBJECTIVES: Biliary tract tumors have a poor prognosis despite advancements in targeted therapies. More recent studies have started to investigate the use of combination immunotherapy in advanced biliary cancers. However, currently, there are no clinical trials investigating the use of dual-agent immunotherapy with ipilimumab and nivolumab as a sequential treatment after patients have progressed on single-agent immunotherapy. In this case series, we discussed 3 patients with advanced cholangiocarcinoma who have an objective response to dual-agent immunotherapy with ipilimumab and nivolumab after having disease progression on pembrolizumab and multiple other failed lines of treatment. MATERIALS AND METHODS: A case series, including 3 patients treated at the University of California, Irvine Chao Family Comprehensive Cancer Center, was completed. RESULTS: Although none of the 3 patients had microsatellite instability or high tumor-mutation burden and were not necessarily predicted to have a response to dual-agent immunotherapy, all 3 patients had an objective radiographic and/or tumor-marker response to a combination of ipilimumab and nivolumab. CONCLUSIONS: This case series serves as proof of the concept that sequential immunotherapy can be beneficial after progression on single-agent immunotherapy for patients with advanced cholangiocarcinoma. This study can also serve as the foundation to build further tests on the true effectiveness and ideal duration of sequential therapy with dual immunotherapy agents.

Iron deficiency and iron excess damage mitochondria and mitochondrial DNA in rats.

Approximately two billion people, mainly women and children, are iron deficient. Two studies examined the effects of iron deficiency and supplementation on rats. In study 1, mitochondrial functional parameters and mitochondrial DNA (mtDNA) damage were assayed in iron-deficient (< or =5 microg/day) and iron-normal (800 microg/day) rats and in both groups after daily high-iron supplementation (8,000 microg/day) for 34 days. This dose is equivalent to the daily dose commonly given to iron-deficient humans. Iron-deficient rats had lower liver mitochondrial respiratory control ratios and increased levels of oxidants in polymorphonuclear-leukocytes, as assayed by dichlorofluorescein (P < 0.05). Rhodamine 123 fluorescence of polymorphonuclear-leukocytes also increased (P < 0.05). Lowered respiratory control ratios were found in daily high-iron-supplemented rats regardless of the previous iron status (P < 0.05). mtDNA damage was observed in both iron-deficient rats and rats receiving daily high-iron supplementation, compared with iron-normal rats (P < 0.05). Study 2 compared iron-deficient rats given high doses of iron (8,000 microg) either daily or every third day and found that rats given iron supplements every third day had less mtDNA damage on the second and third day after the last dose compared to daily high iron doses. Both inadequate and excessive iron (10 x nutritional need) cause significant mitochondrial malfunction. Although excess iron has been known to cause oxidative damage, the observation of oxidant-induced damage to mitochondria from iron deficiency has been unrecognized previously. Untreated iron deficiency, as well as excessive-iron supplementation, are deleterious and emphasize the importance of maintaining optimal iron intake.