After famously retreating from oncology, GSK's re-entry is not a broad effort. Their CSO clarifies a focused strategy anchored in two key areas: hematology (blood cancers) and solid tumors that are genetically unstable (DMMR/MSI high), with a particular emphasis on women's cancers like endometrial cancer.

The pharmaceutical industry's focus on rare diseases has intensified, with 57% of all novel drugs approved in 2025 designated as orphan treatments. This is a continued increase from prior years, indicating a strategic shift towards smaller patient populations with high unmet needs, as exemplified by three different drugs for Hereditary Angioedema (HAE) being approved within ten weeks.

Mirum views the retreat of large pharmaceutical companies from the rare disease space as a strategic opportunity. This creates a less competitive environment for acquisitions, allowing Mirum to acquire assets that are often overlooked by larger players and serve patient populations others leave behind.

The old assumption that small biotechs struggle with commercialization ("short the launch") is fading. Acquirers now target companies like Verona and Intracellular that have already built successful sales operations. This de-risks the acquisition by proving the drug's market viability before the deal, signaling a maturation of the biotech sector.

GSK's $2.2 billion acquisition of Wrap Therapeutics for a Phase 2b food allergy antibody demonstrates a high-conviction strategy. Instead of a typical licensing deal with milestones and royalties, GSK chose full ownership, indicating immense confidence in the mid-stage asset and a desire to control its entire development and commercial future.

In the rare disease space, success hinges on deep patient community engagement. Smaller, nimbler biotechs often excel at creating these essential personal ties, giving them a significant advantage over larger pharmaceutical companies.

Renowned gene therapy pioneer Jim Wilson was forced to spin out ultra-rare disease programs into a new company after his initial venture failed to attract VC funding. This demonstrates that even elite scientific leadership cannot overcome investor disinterest in this segment without powerful, predictable government incentives like transferable priority review vouchers.

In a crowded field, GSK's CSO explains their choice of the FGF21 molecule "Effie" was driven by three specific technical advantages: a longer half-life enabling monthly dosing for sicker patients, easier manufacturing via mammalian systems, and the lowest immunogenicity profile compared to competitors.

When asked about complex antibodies like ADCs and bispecifics, GSK's CSO emphasizes that extending a drug's duration is a primary innovation. He highlights a severe asthma treatment dosed just twice a year as a prime example of creating significant patient value before adding further engineering complexity.