Bloomberg Businessweek: Vir Bio's Cancer Treatment Progress Driving Shares Higher

Hosts: Carol Massar & Tim Stenovec
Guest: Marianne de Backer, CEO of Vir Biotechnology
Date: March 2, 2026

Episode Overview

This episode centers on the latest advancements from Vir Biotechnology in developing a novel cancer immunotherapy for metastatic prostate cancer. Hosts Carol Massar and Tim Stenovec discuss with Dr. Marianne de Backer (CEO, Vir Biotechnology) their promising phase one data, a major partnership with Astellas Pharma, and implications for cancer care and the biotech sector.

Key Discussion Points & Insights

Vir Biotechnology’s Breakthrough in Prostate Cancer Therapy

• Data Release and Market Impact: Vir Biotechnology's shares surged over 20% after announcing updated phase one trial results and a new collaboration with Astellas Pharma (02:16).
  • Vir's drug candidate, VR5500, is a "mask T cell engager" showing strong results in heavily pre-treated metastatic prostate cancer patients.

Details on Phase One Data and Efficacy

• Patient Response:
  • Out of 58 patients treated, the "efficacious dose" subset (22 patients) had:
    • 82% showing PSA 50 declines (a key cancer biomarker)
    • 53% achieving PSA 90 declines
  • Notable quote (Marianne de Backer, 03:38):

    "We have patients who have really exhausted all, all lines of therapy... and even in those patients we could see, see quite dramatic results. Sometimes even only after nine weeks of treatment, you could see that all those lesions were really disappearing."

• Real Patient Case:
  • 63-year-old with five prior therapies, extensive metastasis (including 14 liver lesions), experienced a 99% decline in PSA after nine weeks of VR5500.
  • (04:49) Dr. de Backer:

    "A picture says more than a thousand words. You see all these liver lesions and other tumor lesions really disappearing... the way this works is really we are trying to activate the patient's own immune system to fight the cancer."

Expansion Plans and Patient Population

• Broader Application:
  • The phase one trial began with late-line (treatment-resistant) cases. Next steps include expansion to earlier-line patients and combination therapies.
  • (07:52) Marianne de Backer explains:

    "We are starting three expansion cohorts already in the next quarter... looking at late-line, early-line with combination therapy, and metastatic hormone sensitive patients."

Mechanism of Action: Immunotherapy Innovation

• How VR5500 Works:
  • Unlike CAR-T, VR5500 activates native T cells within the tumor without removing and re-engineering them.
  • (09:33) Dr. de Backer:

    "We're really just activating the T cells that are already there in the tumor of the patient."

Individual Variation and Personalized Care

• Patient Variation:
  • Thus far, high response rates across the trial. No clear determinants for non-response yet.
  • (09:33)

    "We haven't seen determinants of patients that would respond versus not respond. That's not what we see in our data. We see generally patients responding very well."

Industry Implications and Partnership

• Big Pharma Interest:
  • Carol asks about potential acquisition; Dr. de Backer emphasizes strategic partnership over acquisition at this time.
  • (10:48) Dr. de Backer:

    "We realized that as a small biotech company... we would really benefit from a partner... We had a lot of companies coming in and as you have seen, we have eventually chosen Astellas."

  • Chose Astellas for their experience and 50/50 profit sharing model; Astellas leads in prostate cancer therapeutics.

Notable Quotes & Memorable Moments

• On seeing dramatic patient results (06:26):

  • Marianne de Backer:

    "It really gave us chills when we saw this."

• On innovation versus acquisition (10:26):

  • Tim Stenovec:

    "A lot of times the larger pharmaceutical companies end up making acquisitions rather than developing the technology themselves."

• On near-future plans (12:28):

  • Marianne de Backer:

    "We are starting expansion trials... next quarter and our plan is to go into registration of trials next year."

Timestamps for Key Segments

• 02:16 – Introduction to Vir Biotechnology’s news and stock surge
• 03:38 – Dr. de Backer explains phase one trial data and patient outcomes
• 04:49 – Dramatic patient case; visual evidence of tumor regression
• 06:26 – Emotional impact of seeing treatment results
• 07:52 – Next steps: expansion cohorts and trial strategy
• 09:33 – Explaining the underlying science and patient variability
• 10:48 – Discussion of industry partnerships and Astellas deal
• 12:28 – Looking ahead: trial timeline and regulatory plans

Summary Flow & Tone

Throughout the conversation, optimism and measured excitement about the real-world implications of Vir’s early-stage therapy come through, particularly in references to visualized patient success and strategic growth. Both hosts focus on the broader context—innovation in biotech, the role of partnerships, and the path from early trials to eventual commercialization—ensuring listeners see both the scientific and market impact.

This episode provides a hopeful, nuanced outlook on a potential breakthrough in prostate cancer and an insider’s view of biotech innovation and deal-making.