Dominic Rose

Dominic Rose from Leerink Partners asked for an explanation of the channel mix effects that drove the LINZESS rebate in Q4 2025 and whether similar pricing volatility should be expected in 2026. He also inquired about the observed fall in LINZESS commercial volume at the beginning of the year and the current formulary positioning compared to the prior year.

Answer

Gregory Martini, SVP and CFO, clarified that the Q4 2025 pricing impact was due to the timing of gross-to-net rebate reserve recognition, where units dispensed exceeded units sold to wholesalers, rather than channel mix. He stated that this disproportionate impact was specific to Q1 and Q4 2025 and that 2026 is expected to show more sequential consistency without similar volatility. Tammi Gaskins, Chief Commercial Officer, confirmed that Ironwood has maintained broad patient access for LINZESS across commercial and Medicare Part D plans, a key outcome of the WAC reduction. Thomas McCourt, CEO, added that the observed reduction in volume at the start of the year is a typical seasonal pattern due to high-deductible plans resetting, and the drug remains on a linear growth curve.

Dominic Rose asked about the channel mix effects that drove the LINZESS rebate in Q4 and whether ongoing pricing volatility should be expected in 2026. He also inquired about the observed fall in LINZESS commercial volume at the beginning of the year and the current formulary positioning compared to the prior year.

Answer

Gregory Martini, SVP and CFO, clarified that Q4 LINZESS pricing was impacted by the timing of gross-to-net rebate reserve recognition, not channel mix, due to higher dispensed units versus units sold to wholesalers. He expects less quarter-over-quarter volatility in 2026. Tammi Gaskins, Chief Commercial Officer, stated that LINZESS has maintained broad patient access across commercial and Medicare Part D, with the lowered WAC price supporting this. Thomas McCourt, CEO, explained that the observed volume reduction at the start of the year is typical seasonality due to high-deductible plans resetting, with acceleration expected throughout the year.