US FDA approves GSK's blood cancer treatment

GSK's blood cancer drug Blenrep received FDA approval for one combination regimen (bortezomib and dexamethasone) for relapsed multiple myeloma, signaling its return to the U.S. market after a 2022 withdrawal. This approved combination demonstrated strong efficacy, reducing death risk by 51% and tripling progression-free survival against a J&J therapy, despite the FDA's decision going against an advisory panel and approving only one of two tested regimens. While U.S.-listed shares initially fell 4% after-hours, the approval is expected to boost investor confidence in Blenrep's projected peak sales exceeding £3 billion, positioning it as a key growth driver in the expanding $45 billion multiple myeloma market, though significant sales are not anticipated this quarter.

Analysis

GSK's blood cancer drug, Blenrep, received FDA approval for a single combination regimen (bortezomib and dexamethasone) for relapsed multiple myeloma, marking its return to the U.S. market after a 2022 withdrawal. This approval is significant as the approved combination demonstrated strong efficacy, reducing the risk of death by 51% and tripling progression-free survival compared to a Johnson & Johnson Darzalex-based regimen. The decision, however, was a split one, with a second regimen not approved and going against an advisory panel's prior negative recommendation.

Despite the positive FDA decision, GSK's U.S.-listed shares initially declined 4% in after-hours trading, suggesting some market skepticism or disappointment over the partial approval. Nevertheless, the approval is expected to bolster investor confidence in Blenrep's projected peak sales exceeding £3 billion ($4.03 billion), positioning it as a material growth driver for GSK over the next three to four years within the expanding $45 billion multiple myeloma market. Significant sales are not anticipated this quarter due to the early stages of rollout.

Key Decisions for Investors

• Investors should closely monitor GSK's stock performance and analyst commentary in the coming days to understand the market's long-term interpretation of this partial FDA approval versus the initial negative after-hours reaction.
• Evaluate Blenrep's sales trajectory in upcoming quarters, particularly given the 'no significant sales this quarter' guidance, to gauge its contribution to GSK's revenue growth against the £3 billion peak sales projection.
• Consider the competitive landscape and GSK's broader oncology pipeline, as Blenrep's partial approval and simplified safety monitoring program will influence its ability to gain market share in the competitive multiple myeloma market.