Immunomedics has signed up Seattle Genetics as the licensee for its triple-negative breast cancer (TNBC) drug IMMU-132, getting $300m upfront and another $1.7bn in possible milestone payments.
Seattle Genetics will handle the running of a proposed phase III trial of IMMU-132, an antibody-drug conjugate that twins an antibody targeting the TROP-2 antigen on tumour cells with SN-38, the active metabolite of chemotherapy drug irinotecan. It will also fund the development, manufacturing and commercialization of the drug.
IMMU-132 (also known as sacituzumab govitecan) is currently in a phase I/II trial in TNBC which - if positive - could form the basis for a filing under the FDA's accelerated approval regulations. All being well the drug could be in line for an FDA approval before the end of the year.
Seattle Genetics also gets rights to the drug in other indications, including urothelial cancer (UC), small-cell lung cancer (SCLC) and non-small-cell lung cancer (NSCLC), which are currently at the phase II trial stage, along with other solid tumour indications.
Immunomedics' chief executive Cynthia Sullivan said she believes Seattle Genetics is the right partner as it is an "industry leader" in ADCs, having already brought lymphoma drug Adcetris (brentuximab vedotin) through to market.
"They have a reputation as one of the most successful and well financed standalone ADC companies, with a deep product pipeline," she said. That pipeline does not however have any overlap with IMMUN-132'sbroad target tumour profile - unlike some other suitors.
Moreover, Seattle Genetics "is well positioned to expand into solid cancers with IMMU-132" as it has an existing marketing and sales organization in the US and has started to build this capability in Europe, said Sullivan.
Funding a phase III programme and building a salesforce for IMMU-132 from scratch could cost up to $275m, so a 'go-it-alone' strategy was not considered a good option.
Unusually, under the terms of the deal Immunomedics can also continue negotiating with a limited number of parties that previously expressed interest in licensing IMMU-132 until 19 February, while Seattle Genetics has the right to match any financially higher offer.
Immunmedics will also get double-digit tiered royalties on global net sales and retains the right to co-promote IMMU-132 in the US.