BB Biotech AG

The share price of BB Biotech increased by 13.3% in CHF in September, while the company’s net asset value (NAV) rose by 12.0% in USD. The Nasdaq Biotechnology Index (NBI) closed 4.4% higher in USD.

In September, the biotech sector extended its positive momentum, underpinned by renewed investor appetite for innovation and several important corporate milestones. While the broader NBI delivered a solid monthly gain, BB Biotech’s significantly stronger performance reflects both the quality of its portfolio companies and their ability to deliver tangible clinical and regulatory progress. Broader equity markets also contributed to a constructive backdrop. On September 17, 2025, the US Federal Reserve lowered its key interest rate by 25 basis points to a target range of 4.00% to 4.25%. This decision strengthened expectations of a more supportive monetary environment. As a result, sentiment for growth-oriented sectors such as biotechnology improved, since lower interest rates reduce financing costs.

The sector’s resilience was also highlighted by the uptick in strategic M&A activity. Large pharmaceutical companies continued to pursue pipeline-enhancing assets, a trend that confirms sustained appetite for differentiated medicines and the potential for value-creating deals. Even in a cautious macroeconomic setting, high-quality biotech assets have demonstrated their ability to attract substantial premiums.

An important milestone for BB Biotech was its inclusion in the SPI ESG Index of SIX Swiss Exchange as of September 22, 2025. This recognition underscores BB Biotech’s long-standing commitment to responsible investing and sustainable corporate governance. The index inclusion also provides investors with a transparent ESG benchmark and highlights the long-term attractiveness of BB Biotech’s portfolio from both a financial and sustainability perspective.

Selected highlights in September from BB Biotech’s portfolio companies:

Ionis Pharmaceuticals (+53%, in USD) reported very positive news in early September, as its drug olezarsen showed impressive results in a large clinical trial for patients with extremely high blood fat levels (severe hypertriglyceridemia). In addition to significantly lowering these harmful lipids, the therapy also markedly reduced the risk of painful and sometimes life-threatening inflammatory attacks of the pancreas (pancreatitis). This positions olezarsen as a potential new standard of care for patients who currently have very few options, with the addressable patient population also expanding significantly.
Alongside this, Ionis also shared encouraging late-stage data for zilganersen in Alexander disease, a devastating rare neurological condition. The trial showed the first signs that a treatment could slow or stabilize the progression of this disease.

Revolution Medicines (+23%, in USD) continued to make encouraging progress with its novel cancer treatments. The company is developing drugs that directly target mutations in the RAS pathway, which play a key role in many hard-to-treat cancers, including pancreatic cancer. Recent clinical data underscored the promise of this approach, strengthening confidence that Revolution Medicines could become a leader in oncology innovation. With a growing pipeline and strong early results, the company is gaining recognition as one of the most ambitious challengers in cancer drug development.

Scholar Rock Holding (+14%, in USD) shifted its focus from clinical results to regulatory review in September. After the publication of pivotal phase 3 data in August, expectations were high ahead of the FDA’s decision on apitegromab. On September 22, however, the FDA issued a complete response letter (CRL) – a formal rejection of its marketing application by the FDA. Importantly, the CRL did not raise concerns about the drug’s safety or efficacy but related instead to manufacturing observations at a third-party facility. Scholar Rock is working with its partner to resolve these issues and intends to resubmit the application, keeping the path open for apitegromab to become the first muscle-targeted therapy for spinal muscular atrophy.