What role do biosimilar and follow-on insulins play?
Lilly's Rezvoglar launched at $92 per five-pack — 78% off Lantus — but PBMs have been accused of favouring high-rebate branded products on better tiers; the Caremark settlement now bars formulary discrimination against lower-cost alternatives.
Cheaper biosimilar insulins should, in theory, drive down prices, but critics argue the rebate system has sometimes worked against them. PBMs have been accused of placing cheaper biosimilar and follow-on insulins on less favourable formulary tiers than high-rebate branded products, because lower list prices generate smaller rebates. Lilly's biosimilar to Sanofi's Lantus, Rezvoglar, launched in April 2023 at $92 per five-pack of pens, a 78% discount to Lantus. The FTC's Caremark settlement specifically bars discrimination against lower-cost versions on formularies. Whether these reforms allow low-list-price insulins to gain share will be an important test of whether the market can shift from rebate competition to price competition.