
ESMO preview – Astra joins the folate fray
First data with Astra’s torvutatug samrotecan come as Lilly unveils its first folate pivotal trial.
First data with Astra’s torvutatug samrotecan come as Lilly unveils its first folate pivotal trial.

In the folate receptor alpha (FRα) space, a new pivotal trial is about to get under way in ovarian cancer. Lilly is gearing up to launch the Framework-01 study of its ADC LY4170156 in November, according to a new clinicaltrials.gov listing.
The trial will evaluate the ADC in both platinum-resistant and platinum-sensitive ovarian cancer patients, and marks the first pivotal study for the asset. Meanwhile, the first human data with AstraZeneca’s torvutatug samrotecan, revealed in an ESMO abstract, suggest that this project could compete with both LY4170156 and Genmab’s rinatabart sesutecan, the leading next-generation contender.
Folate Framework
At ASCO this year, Lilly reported phase 1 data in solid tumours, with a focus on platinum resistant ovarian cancer, where LY4170156 reached a 56% ORR across patients with FRα expression above and below 75% alike.
Updated data to be presented in an ESMO poster show a slight decline, according to an abstract released on Monday. Among 54 platinum resistant ovarian cancer patients, the ORR was 48%; the response rates were 42% among patients with FRα expression of 75% or above, and 50% ORR in those with expression below 75%.
Abbvie’s Elahere remains the only approved FRα-targeting ADC in ovarian cancer, indicated for platinum-resistant patients with ≥75% FRα expression, with a 32-42% ORR cited on its US label. It is also being evaluated in the platinum-sensitive population in the Gloriosa phase 3 trial, expected to read out in 2027.
The other key competitor in the space, Genmab’s rinatabart sesutecan, which originated from ProfoundBio, has reported a 55% ORR in the Rainfol-01 trial where 90% of the patients were platinum resistant.
So data look very similar between LY4170156 and rina-S, although Genmab paid $1.8bn for ProfoundBio, while Lilly is thought to have spent only around $250m on Mablink, which originated LY4170156.
Genmab is already running a pivotal trial with its ADC in ovarian cancer. However, the Rainfol-02 trial, expected to read out in 2026, is only evaluating platinum-resistant ovarian cancer patients. The platinum-sensitive population will be tested in the Rainfol-04 study, which hasn't started yet.
And now another contender is stepping into the ring. According to an ESMO 2025 abstract, in the phase 1/2 Fontana trial AstraZeneca’s torvutatug samroteacan (AZD5335) achieved 61% ORR in platinum-resistant ovarian cancer patients with ≥75% FRα expression, across doses of 1.6mg/kg, 2.0mg/kg and 2.4mg/kg every three weeks. In patients with expression below 25%, ORR was a still respectable 48%. PFS data will be presented during the congress.
Pivotal studies of anti-FRα ADCs
Project | Trial | Indication | Status |
---|---|---|---|
LY4170156 | Framework-01 | Platinum-resistant & sensitive ovarian cancer (Avastin combo), vs Elahere or Avastin | Expected to start Nov 2025; primary completion Apr 2028 |
Rinatabart sesutecan | Rainfol-02 | Platinum-resistant ovarian cancer, vs chemotherapy | Started in Feb 2025; data due 2026 |
Rinatabart sesutecan | Rainfol-04 | Platinum-sensitive ovarian cancer | Expected to start in H2 2025 |
Elahere | Mirasol | Platinum-resistant ovarian cancer, vs chemotherapy | Full approval in March 2024 |
Elahere | Gloriosa | Platinum-sensitive ovarian cancer (Avastin combo), vs Avastin | Primary completion Mar 2027 |
Source: OncologyPipeline.
ESMO will take place in Berlin on 17-21 October.
This story has been updated.
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