Sangamo’s hemophilia A gene therapy revenue forecasts cut after Pfizer exit

Sangamo

Sangamo Therapeutics Inc. (NASDAQ: SGMO) entered 2025 on a weak footing after Pfizer Inc. (NYSE: PFE) withdrew from their joint hemophilia A gene therapy programme, sending Sangamo’s shares sharply lower. The pharmaceutical giant announced it would not pursue regulatory submissions for the gene therapy, giroctocogene fitelparvovec (SB-525), including a Biologics License Application (BLA) in the U.S. and a Marketing Authorization Application (MAA) in Europe. The termination of the collaboration, which became official in April, leaves Sangamo in a difficult position, forcing the biotech firm to explore new partnerships to continue the programme.

The decision came despite encouraging data from the AFFINE trial (NCT04370054), a Phase 3 study showing that nearly two-thirds of patients remained free from bleeding episodes for almost three years after a single treatment. Pfizer’s withdrawal leaves Sangamo without a clear path to market, forcing the biotech to seek a new partner to revive the programme. However, Pfizer’s decision to walk away casts doubt on the appeal of gene therapy to other drugmakers.

Visible Alpha consensus shows analysts have cut 2027 risk-adjusted revenue forecasts for Sangamo’s gene therapy candidate, SB-525, to $1 million — down sharply from previous estimates of $6.2 million — and lowered the probability of regulatory success (POS) to 42% from 76.7%, reflecting uncertainty about Sangamo’s ability to navigate regulatory hurdles and commercialize the therapy without Pfizer’s backing.
Sangamo’s other key pipeline asset, its Fabry disease gene therapy candidate Isaralgagene civaparvovec (ST-920), remains a crucial focus. Currently in Phase 2 trials, ST-920 has a POS of 53%, with analysts forecasting $19.8 million in first-year risk-adjusted revenue, assuming regulatory approval. Peak sales are projected to reach $365 million by 2034.

Sangamo is due to announce its first-quarter 2025 results on Friday, May 9, with analysts expecting revenue of $9 million, up from $7.6 million in Q4 2024 and $0.5 million a year ago. EPS is expected to come in at -$0.12.