Pancreatitis associated with newer classes of antineoplastic therapies

Patients with advanced malignancies may develop pancreatitis during therapy for their cancer. Acute pancreatitis is inflammation of the pancreas. Common symptoms include abdominal pain, nausea, vomiting, shortness of breath, dehydration. Laboratory evidence of acute pancreatitis includes elevations of the amylase and lipase. Mild pancreatitis occurs when there is no organ dysfunction, moderate pancreatitis is associated with one organ dysfunction, and severe pancreatitis is complicated by multiple organ dysfunction. Hypotension, hypocalcemia, or anemia suggest a more severe course of the pancreatitis. In some instances, the pancreatitis may be an adverse reaction to the therapy being given. However, other causes such as hypercalcemia, hypertriglyceridemia, cholelithiasis, and underlying malignancy must be ruled out before ascribing pancreatitis to a specific drug. To date, two classifications systems have been proposed by Trivedi¹ and Badalov² to evaluate the degree to which a drug is responsible for pancreatitis (Table 1). Furthermore, Naranjo and colleagues have proposed a more general method of assessing the causal relationship between drugs and adverse events.³ The Naranjo algorithm is not specific for pancreatitis. Jones and colleagues⁴ reported that 0.1%-2% of acute pancreatitis cases were owing to drugs. In 2015, they listed the older chemotherapy agents associated with pancreatitis. However, more recently, many new agents have been approved for the management of cancers. The newer classes of antineoplastic agents including proteasome inhibitors, immune-modulating agents, tyrosine kinase inhibitors, monoclonal antibodies against programmed cell death-1 (PD-1) and its ligand PD-L1 and antibody-toxin conjugates are now associated with acute pancreatitis.

Methods

We conducted a search in PubMed, Google Scholar, and Micromedex for pancreatitis related to antineoplastic agents, including proteasome inhibitors, immune checkpoint inhibitors, monoclonal antibodies, immune-modulating agents, drug-induced pancreatitis. Terms used for the searches included each specific agent and pancreatitis, immunotherapy and pancreatitis, tyrosine kinase inhibitors and pancreatitis, auto immune pancreatitis, and toxicities of molecular target therapies. Reference lists from the identified manuscripts were reviewed for further studies of pancreatitis as a result of antineoplastic therapy. The most recent search date was February 15, 2017.

The degree to which each agent was associated with inducing pancreatitis was evaluated using the Badalov classification system² in addition to the Naranjo Adverse Drug Reaction (ADR) Probability Scale.³ The Naranjo scale consists of 10 questions with values assigned to each answer. Total scores range from -4 to 13, where 13-9 indicates the reaction is considered definitely attributable to the drug; 8-5, probably attributable; 4-1, possibly attributable; and ≤0, doubtful if attributable.

A total of 67 manuscripts and abstracts were identified. Four manuscripts and 3 abstracts were excluded because they had insufficient information about possible pancreatitis or there was a presence of multiple other agents or conditions that might have caused pancreatitis. In total, 60 publications met inclusion criteria and were evaluated.

Results

Immune checkpoint inhibitors

In a review of toxicities of anti-programmed cell death-1 (PD-1) therapy, pancreatitis was reported to occur in about 1.8% of patients who received nivolumab or pembrolizumab.⁵ The 9 patients with pancreatitis attributed to an immune etiology were treated with corticosteroids. Pancreatitis was grade 2 in 3 patients (1.5-2 times upper limit of normal [ULN]), grade 3 in 4 patients (>2-5 ULN), and grade 4 ( >5 ULN) in 2 patients.

In asymptomatic individuals, pancreatitis has been detected on a positron-emission tomography–computed tomography (CT) scan after anti-PD-1 therapy.⁵ By contrast, there was a case report of a patient treated with nivolumab for lung cancer who developed anorexia, vomiting, and back pain on day 18 of therapy with an elevation of the amylase and lipase levels, but a negative CT.⁶ Later the patient developed a swollen pancreas on CT. Autoimmune pancreatitis comes in two forms. The most common relates to elevated levels of immunoglobulin G4 (IgG4; normal, 135 mg/dL ULN)⁷ The mechanism of immune pancreatitis associated with anti-PD-1 therapy is unknown.

Ipilimumab (an anti-CTLA4 antibody) has been approved by the US Food and Drug Administration (FDA) for the treatment of melanoma. Pancreatitis occurred in 1 patient in a phase 1 trial in pediatric patients.⁹ In a summary of 14 phase 1-3 trials of ipilimumab in advanced melanoma, pancreatitis was reported in fewer than 1% of the patients.¹⁰ In management guidelines for therapy with ipilimumab, pancreatitis may present as an asymptomatic increase in the levels of amylase and lipase, or with fevers, malaise, or abdominal pain. Oral prednisone or dexamethasone were given for the immune pancreatitis, but the decline in enzymes was slow, often taking months.¹¹ In a preclinical model of autoimmune pancreatitis due to the blocking of CTLA4, there was suppression of regulatory T-cell function. The autoimmune pancreatitis responded to cyclosporin or rapamycin but there are no clinical data for these agents.¹² The anti-PD-L1 agent atezolizumab has been associated with acute pancreatitis in 2 of 1,978 patients (0.1%).¹³ A review by Champiat and colleagues on dysimmune toxcities related to immune checkpoint inhibitors includes pancreatitis as an autoimmune complication of such therapies.¹⁴

Blinatumomab is an anti-CD19–directed CD3 T-cell engager that has been approved by the FDA for refractory B-cell acute lymphoblastic leukemia. In August 2016, the maker of the drug, Amgen, advised hematologists and oncologists that since February 2016, 10 patients out of more than 2,000 treated with blinatumomab had developed pancreatitis.¹⁵ Other medications the patients were receiving such as high-dose steroids might have caused or contributed to the pancreatitis. In one case, the pancreatitis improved with stopping blinatumomab but worsened with re-challenge. It is possible that the mechanism of the associated pancreatitis relates to a change in immune checkpoint inhibition. CD19-positive, CD24-high, CD27-positive regulatory B cells are decreased in autoimmune pancreatitis.¹⁶ Treatment with blinatumomab may decrease the CD19-positive cells.