Pfizer has agreed a broad-ranging alliance with BioAtla – valued at up to $1bn – to develop a new class of antibody-based drug for a vartiety of cancer targets.
The cross-licensing deal will see BioAtla’s Conditionally Active Biologic (CAB) platform combined with Pfizer’s antibody-drug conjugate (ADC) technology to overcome one of the current limitations of ADC drugs – a tendency to affect non-diseased tissues.
CABs are immunotherapeutic drugs that bypass healthy tissue and bind to target antigens only on diseased cells, a selective process triggered by the microenvironment surrounding the tumour. Only when bound will the CAB release its ADC payload into the cell, killing it.
The use of CAB antibodies for delivery could dramatically increase the number of tumour-associated antigens that are addressable with ADC technology, according to the two companies.
Under the terms of the deal, Pfizer and BioAtla have taken out a licence to each other’s technology and will collaborate on the development of several CAB-ADC antibodies.
Pfizer has also taken an exclusive option on BioAtla’s CAB antibodies against CTLA4, an immune checkpoint targeted by drugs such as Bristol-Myers Squibb’s Yervoy (ipilimumab), further boosting its presence in the fast-growing immuno-oncology category.
While Yervoy has shown increased efficacy when added to PD-1 inhibitors such as BMS’ Opdivo (nivolumab), the combination is associated with a much higher side effect burden. Using a CAB-ADC against CTLA4 that only activates around tumours could be a big advance, according to BioAtla.
Pfizer – currently in the throes of a $160bn takeover of Allergan – has been something of a laggard in immuno-oncology. It has bolstered its position considerably in the last year, however, notably via a $2.85bn alliance with Merck KGaA giving it joint development rights to PD-L1 inhibitor avelumab.
BioAtla and Pfizer are both eligible to receive milestone payments and royalties based on individual CAB-ADC antibody candidates developed and sold by the other party.
San Diego-based BioAtla also has laboratories in China and in June raised $30m from a Chinese investment group.