Blueprint for Breakthroughs is a LinkedIn newsletter published by Adrienne B. Mendoza, MHA, SVP BioBridge Global and Chief Operating Officer (COO), BBG Advanced Therapies
Originally published on LinkedIn on August 12, 2025
Most of us didn’t choose to work in cell and gene therapy because it was easy. We chose it because somewhere, right now, a patient is waiting – a parent hoping to see their child grow up, a young adult wanting more than borrowed time, an older patient wishing for one more healthy year with their family. This is the heart of our work: turning science into survival, moving breakthroughs from bench to bedside as quickly, safely, and reliably as possible. In my last article, we explored the critical role of potency assays in ensuring advanced therapies deliver on their promise. Today, I want to go further, because when potency testing gaps trigger regulatory delays, the journey slows, and every single day matters.
Two clocks start ticking at once: the patient clock and the sponsor clock. For patients, each lost day can mean disease progression or the loss of eligibility for treatment. For sponsors, each lost month can mean millions in unrealized revenue and a shrinking window to make an impact.
Potency: The Cornerstone of Efficacy – and a Hidden Risk
Potency is not simply a measure of “strength”; it is the clinical fingerprint of a therapy’s intended biological effect. For advanced therapies, potency directly impacts dose accuracy, regulatory approval, and commercial scalability.
Yet, despite the industry’s advances in sourcing and processing starting materials, potency testing too often remains an afterthought—becoming a silent bottleneck that delays development and obstructs market entry.
The scale of the problem is clear: according to a review of Advanced Therapy Medicinal Product (ATMP) applications at the European Medicines Agency, nearly 50% encountered potency-related issues during regulatory assessment, often resulting in significant delays. Former FDA CBER Director Peter Marks has similarly noted that potency-related problems are among the most common reasons for delayed approvals in cell and gene therapies. (Alliance for Regenerative Medicine, 2023, Solvias, 2024)
“Potency-related problems have been among the most common reasons for delayed approvals in the field” – Peter Marks, M.D., Ph.D.)
The Patient Clock Is Always Ticking
In advanced therapies, the patient clock is relentless. For individuals facing aggressive diseases like relapsed large B-cell lymphoma, the waiting period is not neutral—it’s dangerous. Clinical data suggest that 20–25% of patients may lose performance status each month without effective therapy, potentially disqualifying them from receiving CAR-T or other advanced treatments (NCCN Guidelines, 2024).
The patient-day loss metric helps make the scale of harm visible. In a high-yield allogeneic CAR-T scenario, where one batch may treat 100 patients, a one-month potency-related delay equals 3,000 patient-days without therapy, more than eight years of cumulative lost treatment time across the waiting population.
The Financial Clock Is Ticking, Too
Potency failures aren’t just a clinical problem, they’re a financial one. Each month of delay for a high-value therapy can cost $5–$15 million in lost revenue (Precedence Research, 2024). This doesn’t include the added costs of prolonged manufacturing holds, supply chain disruptions, or the opportunity cost of missed patient enrollment in clinical trials.
For sponsors, every month saved in regulatory review is a month of additional patient treatments and realized revenue. Potency readiness is, therefore, not just a regulatory compliance measure, it’s a risk mitigation strategy and a competitive advantage.
Bridging the Two Clocks
Everyone in this field shares a common mission: to see transformative therapies reach patients who need them, on time, every time. But potency gaps put that mission at risk, slowing both the delivery of care and the realization of a therapy’s full potential in the market. The tragedy is that these delays are often avoidable.
The path forward is clear:
- Integrate potency strategy from day one—design assays around the therapy’s mechanism of action so they measure what truly matters for efficacy.
- Validate under GMP conditions early—don’t wait for late-stage development to stress-test your assay in the same conditions you’ll face at scale.
- Engage regulators proactively—align on expectations before you submit, reducing the risk of rework or rejection.
When potency testing is embedded as a core capability rather than a downstream checkbox, we bridge the patient clock and the sponsor clock. We protect timelines, safeguard budgets, and, most importantly, keep our promise to the people who are waiting.
Here to Help You – And Through You, The Patients
If you’re developing an advanced therapy, potency planning is mission-critical. The patients you serve can’t afford preventable delays, and neither can your program. At BBG Advanced Therapies, we partner with sponsors to design potency strategies that stand up to regulatory scrutiny, scale with manufacturing, and protect both timelines and patient access.
Every day saved in potency readiness is a day gained for a patient’s future. Let’s make sure no one waits longer than necessary, and no therapy loses momentum to save a life.
📩 Connect with us at bbgat.org or through our Contact Us page. Together, we can bridge the gap between breakthrough science and the patients who need it.
References
Alliance for Regenerative Medicine. (2023, March 22). Addressing potency assay-related development delays for cell and gene therapies [White paper]. https://alliancerm.org/wp-content/uploads/2023/03/Addressing-potency-assay-related-development-days-for-cell-and-gene-therapies-March-22.pdf
National Comprehensive Cancer Network. (2024). B-cell lymphomas (Version 2.2024). NCCN Clinical Practice Guidelines in Oncology. https://www.nccn.org/professionals/physician_gls/pdf/b-cell.pdf
PDA. (2024). Continuing the conversation for better ATMP development. Parenteral Drug Association. https://www.pda.org/pda-letter-portal/home/full-article/continuing-the-conversation-for-better-atmp-development
Precedence Research. (2024). Advanced therapy medicinal products market size, share, growth trends 2024 to 2034. https://www.precedenceresearch.com/advanced-therapy-medicinal-products-market
Solvias. (2024). The potency puzzle: Overcoming potency assay challenges for ATMPs [White paper]. https://www.solvias.com/wp-content/uploads/2024/08/White-Paper-The-Potency-Puzzle.pdf
