8-K: Immunocore Announces Promising Phase 1 Data for Brenetafusp in Cutaneous Melanoma

Immunocore's brenetafusp shows encouraging disease control and progression-free survival in pre-treated cutaneous melanoma patients, particularly those with PRAME-positive tumors.

Summary

• Immunocore has released updated Phase 1 clinical trial data for brenetafusp (IMC-F106C), a bispecific ImmTAC molecule targeting PRAME, in patients with cutaneous melanoma who had previously been treated with immune checkpoint inhibitors.
• The data, presented at the 2024 ASCO Annual Meeting, shows that brenetafusp demonstrated a 56% disease control rate (DCR) in monotherapy, with 11% of patients achieving a partial response and 44% achieving stable disease.
• In PRAME-positive patients, the DCR was 58%, with a median progression-free survival (mPFS) of 4.2 months, compared to 2.1 months in PRAME-negative patients.
• A molecular response, measured by ctDNA reduction, was observed in 42% of PRAME-positive patients, and these patients showed a trend towards longer PFS and overall survival.
• Brenetafusp was well-tolerated both as a monotherapy and in combination with anti-PD1 therapy, with manageable side effects.
• The company is currently enrolling patients in a Phase 3 clinical trial (PRISM-MEL-301) of brenetafusp with nivolumab in first-line advanced cutaneous melanoma.
• The Phase 3 trial will randomize patients to brenetafusp plus nivolumab versus nivolumab or nivolumab plus relatlimab, depending on the country of enrollment.

Sentiment

Score: 8

Explanation: The document presents positive clinical data for brenetafusp, highlighting its efficacy and tolerability. The advancement to a Phase 3 trial further boosts confidence. While there are some risks and side effects, the overall tone is optimistic.

Positives

• Brenetafusp shows promising clinical activity in late-line cutaneous melanoma patients who have previously failed checkpoint therapies.
• The drug is well-tolerated, both as a monotherapy and in combination with anti-PD1 therapy.
• Clinical benefit is enriched in PRAME-positive patients, suggesting a targeted approach is effective.
• The observed disease control and PFS compare favorably to other immunotherapies in similar patient populations.
• The company is advancing to a Phase 3 trial, indicating confidence in the drug's potential.

Negatives

• The most frequent treatment-related adverse events were Grade 1 or 2 cytokine release syndrome (CRS) and rash, although these were manageable.
• There was one dose-limiting toxicity (transaminitis) reported in one patient in the combination therapy group.
• The median PFS in PRAME-negative patients was only 2.1 months, indicating a need for further research in this subgroup.

Risks

• The Phase 3 trial is still ongoing, and the results are not yet known.
• The drug's efficacy may vary in different patient populations and settings.
• There are potential risks associated with cytokine release syndrome (CRS), although these were generally manageable in the Phase 1 trial.
• The company is reliant on a collaboration with Bristol Myers Squibb for the supply of nivolumab.

Future Outlook

The company is focused on the ongoing Phase 3 trial of brenetafusp in first-line advanced cutaneous melanoma and is continuing to explore the potential of brenetafusp in other solid tumors and in combination with other therapies.

Management Comments

• Dr. Omid Hamid stated that brenetafusp continues to demonstrate promising monotherapy clinical activity in late-line cutaneous melanoma patients.
• David Berman mentioned that the best measure of brenetafusp monotherapy activity is disease control, which is observed in 56% of checkpoint pre-treated melanoma patients.
• David Berman also stated that they expect brenetafusp PFS to be even higher in first-line based on their analysis of blood T cell fitness.

Industry Context

This announcement is significant as it provides further evidence of the potential of ImmTAC molecules in treating cancer. The results are particularly relevant in the context of the ongoing need for effective therapies for patients who have failed checkpoint inhibitors. The company is competing with other companies developing immunotherapies for melanoma.

Comparison to Industry Standards

• The document states that the disease control and PFS benefit for brenetafusp-treated melanoma patients compares favorably to data with other immunotherapies, but does not provide specific comparisons.
• KIMMTRAK, another Immunocore product, is mentioned as an approved therapy for uveal melanoma, demonstrating the company's ability to bring ImmTAC molecules to market.
• The Phase 3 trial design, comparing brenetafusp plus nivolumab to nivolumab or nivolumab plus relatlimab, is consistent with standard practices in melanoma clinical trials.

Stakeholder Impact

• Shareholders will likely view the positive clinical data as encouraging.
• Patients with cutaneous melanoma may benefit from this new treatment option.
• Employees of Immunocore will be involved in the ongoing clinical trials and development of brenetafusp.
• The collaboration with Bristol Myers Squibb is important for the supply of nivolumab.

Next Steps

• The company will continue enrolling patients in the Phase 3 PRISM-MEL-301 trial.
• The company will continue to explore the potential of brenetafusp in other solid tumors and in combination with other therapies.
• The company will present the advanced cutaneous melanoma data from the ongoing Phase 1/2 trial of brenetafusp at the 2024 American Society of Oncology (ASCO) Annual Meeting.

Key Dates

Keywords

brenetafusp, IMC-F106C, cutaneous melanoma, PRAME, ImmTAC, immunotherapy, clinical trial, ASCO, checkpoint inhibitors, nivolumab, progression-free survival, disease control rate, ctDNA, T cell fitness