VEGF bispecific fast lane

The term "VEGF bispecific fast lane" refers to the accelerated development and competitive landscape surrounding VEGF bispecific antibodies in oncology, particularly in the context of Pfizer's strategic initiatives and the broader industry trends. Here's a detailed breakdown of the concept:

### 1. **What is VEGF Bispecific Therapy?**

VEGF bispecific antibodies are a class of immunotherapies that target two pathways simultaneously:

• **PD-(L)1 blockade**: Enhancing immune activation by inhibiting the PD-(L)1 pathway, which tumors exploit to evade immune system attacks.
• **VEGF inhibition**: Normalizing tumor vasculature and disrupting the blood supply tumors need to grow, leveraging anti-angiogenesis mechanisms.

This dual-action approach has shown promise in preclinical and early clinical trials, offering a synergistic effect that could surpass the efficacy of single-pathway inhibitors like Keytruda (pembrolizumab).

### 2. **Why is it a "Fast Lane"?**

The term "fast lane" reflects the urgency and rapid progress in developing VEGF bispecific therapies due to their potential to revolutionize cancer treatment. Key factors contributing to the fast lane include:

#### a. **Intense Competition Among Global Players**

• Pfizer's PF-08634404 is entering pivotal phase 3 trials for **non-small cell lung cancer (NSCLC)** and **colorectal cancer (CRC)**, directly competing with other VEGF bispecific candidates like:
• **Ivonescimab** (Summit/Akeso): Already in phase 3 trials for NSCLC and CRC.
• **Pumitamig** (BioNTech/Bristol Myers Squibb): Set to begin phase 3 trials in 2026.
• The competition is fierce, with companies racing to achieve regulatory approval and market dominance in this emerging class.

#### b. **High Confidence in the Molecule**

• Pfizer is launching fully-fledged phase 3 trials for PF-08634404 from the outset, skipping adaptive phase 2/3 designs used by competitors. This signals strong confidence in the molecule's efficacy and safety profile, based on preliminary phase 2 data.

#### c. **Strategic Timing**

• Pfizer's first trial readouts are expected in late 2026 to early 2027, aligning with competitor milestones (e.g., Akeso's Harmoni-3 results in H2 2026 and H1 2027). This timing positions Pfizer to compete directly in the fast-evolving market.

#### d. **Innovative Mechanistic Rationale**

• The combination of PD-(L)1 and VEGF blockade represents the next major evolution in immuno-oncology, following checkpoint inhibitors. This innovative approach is driving rapid investment and trial launches.

### 3. **Pfizer’s Position in the Fast Lane**

Pfizer has made significant moves to secure its position in the VEGF bispecific fast lane:

• **$1.25 Billion Investment**: Pfizer licensed PF-08634404 (originally SSGJ-707) from China's 3SBio in May 2025, underscoring its commitment to oncology innovation as COVID-19 revenues decline.
• **Global Phase 3 Trials**:
• NSCLC: PF-08634404 + chemotherapy vs. Keytruda + chemotherapy, split by histology (squamous vs. non-squamous).
• CRC: PF-08634404 vs. Avastin + chemotherapy in microsatellite-stable (MSS), non–BRAF-mutant patients—a challenging subgroup with low immunotherapy response rates.
• **Mechanistic Validation**: Preclinical studies and early clinical data have shown strong anti-tumor activity and synergy between PD-(L)1 and VEGF blockade, although toxicity concerns remain.

### 4. **Challenges and Opportunities**

#### Challenges:

• **Toxicity Concerns**: Early phase 2 data from 3SBio highlighted potential safety issues, which will need to be addressed in phase 3 trials.
• **Competitive Pressure**: Pfizer faces direct competition from Akeso, BioNTech/Bristol Myers Squibb, and other Asian biotech pioneers who have led the innovation in bispecific immuno-oncology.

#### Opportunities:

• **Market Impact**: Success in phase 3 trials could establish Pfizer as a top-tier player in bispecific immunotherapy, rivaling Merck's Keytruda dominance in lung and colorectal cancer markets.
• **Innovation Leadership**: By advancing PF-08634404, Pfizer aims to close the innovation gap and position itself as a leader in the next generation of cancer treatments.

### 5. **Industry Context**

VEGF bispecifics are considered the next frontier in oncology, combining immune activation and anti-angiogenesis to tackle difficult-to-treat cancers like MSS colorectal cancer and squamous NSCLC. The "fast lane" refers not only to the speed of development but also to the high stakes and intense competition among pharmaceutical giants and biotech innovators.

### 6. **Future Outlook**

The success of VEGF bispecific therapies, including PF-08634404, will depend on:

• Phase 3 trial outcomes (expected late 2026 to early 2027 for Pfizer).
• Regulatory approval timelines.
• Commercial adoption and market penetration.
• Long-term safety and efficacy data.

In summary, the VEGF bispecific fast lane represents a high-stakes race in oncology innovation, with Pfizer, Akeso, BioNTech/Bristol Myers Squibb, and others vying to lead the next wave of cancer treatment advancements.