A236 LINACLOTIDE IS NOT DETECTABLE IN BREAST MILK OF LACTATING WOMEN: AN OPEN-LABEL, PHASE 1 STUDY

Background

Linaclotide (LIN) is a guanylate cyclase-C agonist approved to treat adults with irritable bowel syndrome with constipation (IBS-C) and chronic idiopathic constipation (CIC). As LIN is a 14-amino acid peptide, no absorption from the gastrointestinal tract is expected following oral administration. However, LIN levels in human breast milk have not been determined.

Aims

To determine the levels of LIN and its active metabolite, MM-419447, excreted in breast milk after multiple once-daily doses of LIN (72 µg, 145 μg, or 290 μg) in lactating women.

Methods

This was a multicenter, open-label, multidose, Phase 1, milk-only lactation study (NCT02220348) in lactating women aged 18–45 years who were actively breastfeeding or pumping for ≥4 weeks and were already taking LIN 72 μg, 145 μg, or 290 μg therapeutically for IBS-C or CIC. Participants continued their LIN dose once daily for the 3 study days, with breast milk extractions at −1 to 0 hours (pre-dose) on Day 1 and −1 to 0 hours and 0–2, 2–4, 4–8, 8–12, 12–16, and 16–24 hours after dosing on Day 3. The pharmacokinetic endpoints were the cumulative amount of LIN and MM-419447 and the percentage dose of LIN excreted into the breast milk over the dosing interval. Adverse events (AEs) were monitored. The study has institutional review board approval.

Results

Seven women were enrolled in the study (IBS-C, n=1; CIC, n=6) and received LIN (72 μg, n=5; 145 μg, n=1; and 290 μg, n=1). Mean age was 28 (range: 19–35), mean weight was 70 kg (standard deviation [SD]: 12 kg), and mean body mass index was 26 kg/m2 (SD: 4 kg/m2); the majority were white (n=6). Concentrations of LIN and MM-419447 in breast milk samples were below the quantitation limits (<0.25 ng/mL and <1.00 ng/mL, respectively) at all time points for all participants. Cumulative exposure for each dose was 216 μg (72 μg dose), 435 μg (145 μg dose), and 870 μg (290 μg dose). One treatment-emergent AE was reported (mild rash).

Conclusions

The data collected in this study provide no evidence that breastfeeding infants receive LIN or MM-419447 through breast milk as their concentrations were below the quantitation limit following multiple once-daily doses of LIN 72 μg, 145 μg, or 290 μg.

Funding Agencies

This study was sponsored by Allergan plc, Dublin, Ireland (prior to acquisition by AbbVie Inc.). Writing and editorial assistance were provided to the authors by Stephanie J. Rippon, MBio, Jane Beck, MA, and Rebecca Fletcher, BA(Hons), of Complete HealthVizion, Inc., Chicago, IL, USA and funded by Allergan plc (prior to acquisition by AbbVie Inc.).

A dose-ranging study of the pharmacokinetics and pharmacodynamics of the selective apoptotic antineoplastic drug (SAAND), OSI-461, in patients with advanced cancer, in the fasted and fed state

PURPOSE

To evaluate the safety, pharmacokinetics and determine the recommended dose of the selective apoptotic antineoplastic drug, OSI-461 administered on a twice-daily regimen to patients with advanced solid malignancies.

METHODS

In this phase I trial, 33 patients were treated with OSI-461 doses ranging from 400 to 1,200 mg given twice daily in 4-week cycles. Pharmacokinetic studies were performed to characterize the plasma disposition of OSI-461 and the effect of food intake on OSI-461 absorption. Secondary biomarker studies were performed to assess the biologic activity of OSI-461 including the measurement of pGSK-3beta, a PKG substrate, and pharmacogenetic studies to identify polymorphisms of CYP3A that influence drug metabolism and of ABCG2, involved in drug resistance.

RESULTS

Thirty-three patients were treated with 86 courses of OSI-461. The dose-limiting toxicities were grade 3 abdominal pain, found in one patient at the 1,000 mg BID fed dose level and all patients at the 1,200 mg BID fed dose level. There was also one episode each of grade 3 fatigue and grade 3 constipation at the 1,000 and 1,200 mg BID fed dose levels, respectively. Other common toxicities included mild to moderate fatigue, nausea, anorexia and mild elevation in bilirubin. Pharmacokinetic studies of OSI-461 revealed approximately a twofold increase in AUC(0-24) when OSI-461 was administered with food. An increase in pGSK-3beta post-dose was seen in the majority of patients and was greater at higher dose levels. No patients exhibited CYP3A4 polymorphisms, while 100% of patients were found to have the CYP3A5*3/CYP3A5*3 polymorphism. Two known polymorphisms of the ABCG2 gene, G34 --> A34 and C421 --> A421, occurred at frequencies of 11.76 and 29%, respectively.

CONCLUSIONS

Toxicity and pharmacodynamic data show that the recommended oral dose of OSI-461 is 800 mg twice daily administered with food. The drug appears to be well-tolerated, and overall bioavailability appears to be markedly increased when the drug is administered with food. These results support further disease-directed evaluations of OSI-461 at a dose of 800 mg BID in combination with other chemotherapeutic agents.