Genmab A/S (GMAB.CO): Upcoming RAINFOL-02 trial likely to be successful on PFS, though magnitude of the benefit needed to support OS and to be competitive is a high bar

Into the upcoming Phase III RAINFOL-02 readout for Rina-S in 2L+ PROC, we have re-evaluated the chances of success. Based on our estimate of the statistical hurdle at 0.80, or a 20% PFS benefit, we see a reasonably high chance of success on PFS. That said, we see the ultimate efficacy profile as remaining challenging to call given trial design factors and baseline characteristics. Whilst the strong Phase II median PFS of 9.5 months is supportive, this was driven by 40% of patients (n=44) and is likely to dilute in Phase III (n=292), leading to our conclusion that the likelihood of Rina-S achieving a Hazard Ratio on PFS of <0.65, which we estimate is likely required for a statistically significant OS result, remains in the balance. We forecast 60% PoS of $1.5bn peak sales for Rina-S in 2L+ PROC, worth c.15% to our NPV post risk adjustment. Overall, while we continue to expect a statistically significant PFS result, we see the bar for a PFS benefit supportive of an ultimate OS benefit as