RTW Biotech notes mixed updates across portfolio companies

(Alliance News) - RTW Biotech Opportunities Ltd on Friday provided updates on three of its key listed holdings, highlighting both promising clinical trial results and a significant setback involving one of its biotech investments.

The London-listed investor focused on high-growth life science assets, noted positive data from Taysha Gene Therapies Inc and Merus NV, while Rocket Pharmaceuticals Inc disclosed a clinical hold following a patient death.

RTW said on Wednesday, Taysha, a Dallas, Texas-based Taysha Gene Therapies Inc, released encouraging interim results from a phase 1/2 trial of its lead candidate TSHA-102 for Rett syndrome. All trial participants, regardless of disease severity, gained or regained at least one developmental milestone - an outcome the company said is unlikely in children over six years old without treatment.

Taysha also disclosed details of its planned pivotal part B trial design, which received alignment from the US Food & Drug Administration.

As of April 30, Taysha made up 0.4% of RTW's net asset value.

Meanwhile, Merus, a Netherlands-based cancer cure developer, saw its shares jump after unveiling interim phase 2 data for its experimental antibody petosemtamab in combination with pembrolizumab for head and neck cancer. The dual-therapy approach showed superior outcomes compared with existing treatments using pembrolizumab alone.

RTW said Merus represented 1.0% of its NAV at the end of April.

In contrast, Rocket Pharmaceuticals reported on May 27 that a participant in a phase 2 trial for RP-A501, targeting the rare heart condition Danon disease, died after experiencing a serious adverse event and subsequent acute systemic infection. The FDA has placed a clinical hold on the trial while the root cause is investigated.

Rocket Pharma made up 3.2% of RTW's NAV at April-end.

RTW Biotech shares were up 0.4% at USD1.15 in London on Friday afternoon.

By Eva Castanedo, Alliance News reporter

Comments and questions to newsroom@alliancenews.com

Copyright 2025 Alliance News Ltd. All Rights Reserved.

Rtw Biotech