Pfizer's ATTR-CM Sales Decline Signals Market Shift as New Players Gain Ground

The transthyretin amyloid cardiomyopathy (ATTR-CM) market, once heralded as a potential $20 billion opportunity, is showing signs of a slowdown. Pfizer's recent report of a 1% year-over-year sales decline for its tafamidis products in the U.S. has raised questions about the market's trajectory and the impact of new entrants.

Market Dynamics and Competition

Pfizer's tafamidis franchise, including Vyndamax and Vyndaqel, saw a 4% sequential decrease in U.S. sales for the quarter ending in September, totaling $948 million. This dip comes less than a year after BridgeBio's launch of Attruby and two quarters following Alnylam's introduction of Amvuttra, signaling a evolving competitive landscape.

Despite the sales decline, Pfizer maintains that demand for Vyndamax continues to grow strongly. The company attributes the revenue drop to rebates under the Inflation Reduction Act and discounts offered in payer contracts.

BridgeBio's CEO Neil Kumar reports that Attruby has gained a significant foothold, estimating its new-to-brand patient share percentage "well in the 20s." Meanwhile, Alnylam reported an approximate doubling in patient demand for Amvuttra in the third quarter compared to the second.

Market Expansion and Diagnosis Rates

ATTR-CM is estimated to affect 250,000 to 300,000 patients in the U.S., with only about 20% currently diagnosed. This low diagnosis rate presents both a challenge and an opportunity for market expansion.

Kumar emphasizes the importance of education and raising awareness beyond centers of excellence. The industry is exploring new diagnostic techniques, including AI algorithms, to help identify potential ATTR-CM patients within the broader heart failure population.

Future Outlook and Challenges

The ATTR-CM market faces several key challenges and opportunities:

1. Tafamidis genericization: Pfizer's tafamidis is expected to lose U.S. patent protection in 2028, potentially accelerating patient volume growth but impacting branded drug sales.

2. Differentiation strategies: Newer entrants like Alnylam and BridgeBio are focusing on differentiating their products from tafamidis and each other. Alnylam is exploring combination therapy potential, while BridgeBio positions Attruby as a more potent first-line stabilizer.

3. Pricing and access: With multiple treatment options available, pricing and reimbursement dynamics will play a crucial role in market share.

4. Clinical data: Ongoing and future clinical trials, including AstraZeneca and Ionis' phase 3 CARDIO-TTRansform trial for Wainua, will shape the competitive landscape.

As the ATTR-CM market continues to evolve, pharmaceutical companies must navigate these challenges while working to expand diagnosis rates and improve patient outcomes. The coming years will likely see intensified competition and potentially new treatment paradigms in this once-promising therapeutic area.