Alnylam and BridgeBio are poised to enter the highly lucrative transthyretin amyloidosis cardiomyopathy (ATTR-CM) market with the backing of an FDA advisory committee and promising phase 3 trial results. However, a survey of 57 doctors who treat the condition suggests that Pfizer’s tafamidis, marketed as Vyndaqel and Vyndamax, is likely to maintain a substantial market share of treated patients, with Leerink Partners analysts estimating it will capture over 60%.
According to Evercore ISI analysts, tafamidis appears deeply entrenched and challenging to displace in the ATTR-CM market. This sentiment is echoed by doctors, as 68% of those polled by Leerink indicated they would only consider using Alnylam’s Onpattro if a patient fails on tafamidis. Tafamidis is favored for its oral administration compared to Onpattro’s infusion method and its established reputation.
Even as Onpattro and BridgeBio’s acoramidis enter the scene, tafamidis is expected to maintain its leadership position. Onpattro received favorable support from FDA advisers last week voted 9-3 in support of the RNA silencer’s use in ATTR-CM. But its “small” benefit in a phase 3 trial raises concerns about replacing tafamidis in newly diagnosed patients.
BridgeBio’s acoramidis, however, might have an advantage in penetrating the market. Acoramidis demonstrated significant reductions in cardiovascular-related death and hospitalization risk in a phase 3 trial compared to a placebo. Over 80% of physicians surveyed by Leerink view acoramidis as an attractive option for ATTR-CM, with some willing to use it as a first-line therapy. Yet, most expect only a minimal shift from tafamidis.
The market dynamics suggest that acoramidis could gain traction due to potential cost advantages over tafamidis, especially considering reimbursement hurdles and out-of-pocket costs for tafamidis patients.
Leerink’s analysts anticipate a different growth trajectory for tafamidis than the Wall Street consensus, projecting it to continue growing from $2.4 billion in 2022 to nearly $4 billion around 2029. As for acoramidis, Leerink estimates it could reach $1.8 billion in sales by 2030, while Onpattro is expected to achieve $654 million in sales by that time.
Alnylam is also seeking FDA approval for its second-generation silencer, Amvuttra, with Leerink’s analysts predicting it could lead the silencer class with potential sales of $3.4 billion by 2030, compared to a consensus estimate of $5 billion.
In summary, while Alnylam and BridgeBio are making strides in the ATTR-CM market, Pfizer’s tafamidis is likely to maintain its dominant position due to factors such as convenience and established trust among physicians. However, acoramidis may have an opening to gain ground, particularly if it can offer a significant cost advantage.