Patient data offers certainty
PIK3CA is not HER2, and the presence of the mutation is necessary but insufficient for spectacular success. Patient data could inform the clinical strategy.
Investment lessons · PIK3CA
When $2 billion buys you a seat – not certainty
Novartis paid $2B+ in early 2026 for a mutant-selective PI3Kα inhibitor. Patient data shows PIK3CA, unlike HER2, is not a solo driver: amplifications driven by a nearby gene, hyperactivated substrate enzymes and co-occurring PI3K or MAPK mutations are likely to reduce response. Pairing biomarker selection with combinations increases the probability of success.
PIK3CA case study · by Pawel Zawadzki, PhD
$2B+
Paid by Novartis in early 2026 for the mutant-selective PI3Kα inhibitor
The case
A rational decision?
PIK3CA-mutated tumors are a high unmet need. There is enough signal in clinical trials from competing products to warrant FDA approval. What's not to like?
PIK3CA is part of the same pathway as HER2, and trastuzumab is one of the most successful oncology drugs of all time. So the expectation is that the mutant-selective PI3Kα inhibitor also will be, but will it?
Patient data
What the patient data revealed
Patient data uncovered that PIK3CA, in contrast to HER2 is not a solo driver. Here are the complications:
- On top of gain-of-function PIK3CA mutations, in many tissues PIK3CA gene gets amplified, likely affecting the ORR in such patients.
- These amplifications are driven by a nearby gene, not PIK3CA itself. Meaning that a likely resistance mechanism is already in place.
- The enzymes synthesizing substrate for PIK3CA are often hyperactivated, likely affecting the therapeutic window.
- In contrast to HER2, PIK3CA mutated tumors are typically “supercharged” by other mutations affecting PI3K or MAPK pathways.
Gene amplification frequencies on chr.3q
The take-home message
In the PI3Kα arms race, $2 billion buys you a seat – not certainty
Commercial opportunity
Yes, biomarkers narrow the addressable population, but pairing biomarker selection with combination therapy exploration increases the probability of success and can recover the lost market size.
Recommendations
Consult patient data for reliable outcomes
01
Clinical data have already proven that PIK3CA is not HER2
Ask the patient data why, and the path for PIK3CAi clinical and commercial success will emerge.
02
Solo vs team player.
Multiple mechanisms reducing the ORR were identified in patient data. Compare the effects of each and build a winning clinical strategy.
03
Patient data should be used before your trial begins.
There's a common misconception that clinical trials are required to assess response rates. Treatment-naive patient data can actually identify factors that limit clinical response before any patients are dosed.
Medicines intended to work in patients should be developed with patient data in mind.