Opioid-induced constipation in patients with cancer pain in Japan (OIC-J study): a post hoc subgroup analysis of patients with lung cancer

OBJECTIVE

To evaluate the opioid-induced constipation burden in the subgroup of patients with lung cancer who participated in the observational Opioid-Induced Constipation in Patients with Cancer Pain in Japan (OIC-J) study.

METHODS

The prospective, observational study, OIC-J, included 212 patients with various tumour types, 33% of whom had lung cancer. The incidence of opioid-induced constipation was evaluated using several diagnostic criteria, as well as the physician's diagnosis and patient's subjective assessment. Following initiation of opioids, patients recorded details of bowel movements (i.e. date/time, Bristol Stool Scale form, sensations of incomplete evacuation or anorectal obstruction/blockage and degree of straining) in a diary for 2 weeks. Relationships between patient characteristics and opioid-induced constipation onset and effects of opioid-induced constipation on quality of life were explored.

RESULTS

In total, 69 patients were included in this post hoc analysis. The incidence of opioid-induced constipation varied (39.1-59.1%) depending on which diagnostic criteria was used. Diagnostic criteria that included a quality component or a patient's feeling of bowel movement as an evaluation item (i.e. Rome IV, physician's diagnosis, Bowel Function Index, patient's assessment) showed higher incidences of opioid-induced constipation than recording the number of spontaneous bowel movements alone. Opioid-induced constipation occurred rapidly after initiating opioids and had a significant impact on Patient Assessment of Constipation Symptoms total score (P = 0.0031). Patient baseline characteristics did not appear to be predictive of opioid-induced constipation onset.

CONCLUSIONS

In patients with lung cancer, opioid-induced constipation can occur quickly after initiating opioids and can negatively impact quality of life. Early management of opioid-induced constipation, with a focus on quality-of-life improvement and patient's assessments of bowel movements, is important for these patients.

Baloxavir marboxil, a novel cap-dependent endonuclease inhibitor potently suppresses influenza virus replication and represents therapeutic effects in both immunocompetent and immunocompromised mouse models

Baloxavir marboxil (BXM) is an orally available small molecule inhibitor of cap-dependent endonuclease (CEN), an essential enzyme in the initiation of mRNA synthesis of influenza viruses. In the present study, we evaluated the efficacy of BXM against influenza virus infection in mouse models. Single-day oral administration of BXM completely prevented mortality due to infection with influenza A and B virus in mice. Moreover, 5-day repeated administration of BXM was more effective for reducing mortality and body weight loss in mice infected with influenza A virus than oseltamivir phosphate (OSP), even when the treatment was delayed up to 96 hours post infection (p.i.). Notably, administration of BXM, starting at 72 hours p.i. led to significant decrease in virus titers of >2-log₁₀ reduction compared to the vehicle control within 24 hours after administration. Virus reduction in the lung was significantly greater than that observed with OSP. In addition, profound and sustained reduction of virus titer was observed in the immunocompromised mouse model without emergence of variants possessing treatment-emergent amino acid substitutions in the target protein. In our immunocompetent and immunocompromised mouse models, delayed treatment with BXM resulted in rapid and potent reduction in infectious virus titer and prevention of signs of influenza infection, suggesting that BXM could extend the therapeutic window for patients with influenza virus infection regardless of the host immune status.