Pharmacokinetic effects of proton pump inhibitors on the novel PARP inhibitor fluzoparib: a single-arm, fixed-sequence trial in male healthy volunteers

Evaluation of Olaparib Tablet Safety and Pharmacokinetics in Healthy Chinese Male Subjects

Purpose

To evaluate the safety and pharmacokinetics of olaparib tablet test formulation (T) and reference formulation (R) in healthy Chinese male subjects.

Subjects and Methods

This was a single-dose, randomized-sequence, two-way crossover study including three parts: part A: a safety exploration design in lower dose (n = 14, 100 mg), part B: a pivotal comparative pharmacokinetic (PK) trial under fast condition (n = 44, 150 mg) and part C: a pivotal comparative PK trial under food condition (n = 44, 150 mg). Blood samples were collected for 72 hours and the PK parameters of Cmax, AUC0-t, and AUC0-∞ were used to evaluate PK differences.

Results

PK analysis of the two olaparib formulations showed that the Geometric Least Squares Mean (GLSM) ratio 90% confidence intervals for pivotal fasting Cmax, AUC0-t, and AUC0-∞ were 94.82-108.97%, 92.94-104.28%, and 92.81-103.85%, respectively, and pivotal fed Cmax, AUC0-t, and AUC0-∞ were 82.78-100.97%, 91.59-104.67%, and 92.17-104.76%, respectively. The 90% confidence interval of the two preparations, Cmax, AUC0-t, and AUC0-∞, all fall within the equivalent range of 80-125%. Both olaparib tablet formulations were well tolerated, with no serious adverse events (SAE) or adverse events (AE) causing withdrawal occurred.

Conclusion

Two types of olaparib tablets were bioequivalent under both fasting and fed condition, and were generally well tolerated in healthy Chinese male subjects.

Drug-drug interactions with proton pump inhibitors in cancer patients: an underrecognized cause of treatment failure

New concepts and drugs have revolutionized medical treatment for cancers. These drugs, which are very expensive and usually well tolerated, have dramatically improved cancer prognosis. We must use them wisely for patients to fully benefit. Gastric acid antisecretory drugs and particularly proton pump inhibitors (PPIs) revolutionized the treatment of gastroduodenal ulcers and severe gastroesophageal reflux, but are frequently overused for symptomatic treatment of epigastric pain or heartburn. Long-term acid suppression may alter the efficacy of many anticancer drugs, such as tyrosine kinase inhibitors (TKIs), cyclin-dependent kinase (CDK) 4/6 inhibitors and immune checkpoint inhibitors (ICIs), by either decreasing gastric acid secretion and thus drug absorption, or by modifying the gut microbiome that modulates the response to ICIs. Oncologists thus need to pay particular attention to the concomitant use of PPIs and anticancer drugs. These interactions translate into major clinical impacts, with demonstrated loss of efficacy for some TKIs (erlotinib, gefitinib, pazopanib), and conflicting results with many other oral drugs, including capecitabine and CDK 4/6 inhibitors. Furthermore, the profound changes in the gut microbiome due to using PPIs have shown that the benefit of using ICIs may be suppressed in patients treated with PPIs. As the use of PPIs is not essential, we must apply the precautionary principle. The first sentence of a recent Comment in Nature was "Every day, millions of people are taking medications that will not help them". We fear that every day millions of cancer patients are taking medications that harm them. While this may well be only association and not causation, there is enough to make us pause until we reach a clear answer. All these data should encourage medical oncologists to refrain from prescribing PPIs, explaining to patients the risks of interaction in order to prevent inappropriate prescription by another physician.

Long-Term Use of Proton Pump Inhibitors in Cancer Patients: An Opinion Paper

Simple Summary

Proton pump inhibitors are frequently used in cancer patients to alleviate some symptoms, epigastric pain or heartburn. However, acid suppression decreases the absorption of some oral-targeted anticancer treatments (tyrosine kinase inhibitors, CDK4/6 inhibitors) and induces changes in the gut microbiome. Recent data are showing that these interactions have important clinical impacts and medical oncologists and patients must be aware of these possible interactions.

Abstract

Multikinase inhibitors (MKIs), and particularly tyrosine kinase inhibitors (TKIs) and immune checkpoint inhibitors (CPIs), are currently some of the major breakthroughs in cancer treatment. Proton pump inhibitors (PPIs) revolutionised the treatment of acid-related diseases, but are frequently overused for epigastric pain or heartburn. However, long-term acid suppression from using PPIs may lead to safety concerns, and could have a greater impact in cancer patients undergoing therapy, like bone fractures, renal toxicities, enteric infections, and micronutrient deficiencies (iron and magnesium). Moreover, acid suppression may also affect the pharmacokinetics of drugs (at least during acid suppression) and decrease the absorption of many molecularly-targeted anticancer therapies, which are mostly weak bases with pH-dependent absorption. This type of drug-drug interaction may have detrimental effects on efficacy, with major clinical impacts described for some orally administrated targeted therapies (erlotinib, gefitinib, pazopanib, palbociclib), and conflicting results with many others, including capecitabine. Furthermore, the long-term use of PPIs results in severe alterations to the gut microbiome and recent retrospective analyses have shown that the benefit of using CPIs was suppressed in patients treated with PPIs. These very expensive drugs are of great importance because of their efficacy. As the use of PPIs is not essential, we must apply the precautionary principle. All these data should encourage medical oncologists to refrain from prescribing PPIs, explaining to patients the risks of interaction in order to prevent inappropriate prescription by another physician.