On 13 September, Gilead announced the acquisition of the biopharmaceutical company Immunomedics for $21B, as the pharma giant looks to bolster its cancer portfolio, specifically targeting Immunomedics’ lead product, Trodelvy (sacituzumab govitecan). The agreement will provide Gilead with the first-in-class Trop-2 directed antibody-drug conjugate (ADC) that was granted accelerated approval by the FDA in April for the treatment of adult patients with metastatic triple-negative breast cancer (mTNBC) who have received at least two prior therapies for metastatic disease. Immunomedics is also on track to file for regulatory approval in Europe in the first half of 2021. This development has come off the back of a string of merger and acquisition (M&A) deals and partnerships for Gilead and against a backdrop of big pharma investing heavily in the ADC market to prepare a gradual shift from systemic chemotherapies to a more targeted approach in the clinic.
Trodelvy is currently only approved in a single aforementioned indication but has experienced rapid adoption, accounting for $20.1M net sales in its first two months of commercial launch, and GlobalData has noted key opinion leader (KOL) enthusiasm for a personalised therapeutic in a subtype of breast cancer characterised by high unmet clinical need. A primary strategic objective for Immunomedics is to establish Trodelvy as a standard of care for third-line mTNBC. Trodelvy is currently well positioned in this clinical setting, given the predominant use of systemic chemotherapies in this setting and the impressive improvements in progression-free survival (PFS) and overall survival (OS) compared to the standard of care in this patient subset, demonstrated in the Phase III ASCENT study. However, the target patient population in this clinical setting is small, constituting approximately 7,000 patients in the US, according to GlobalData estimates. Gilead’s $21B investment is betting on further approvals in other TROP-2-expressing cancers. Specifically, efficacy in the HER2-/HR+ subtype (investigated in the Phase III TROPICS-02 trial) is a key indication for Immunomedics. GlobalData notes that this target population is approximately four times larger than the mTNBC indication and therefore represents a significant commercial opportunity. Further opportunities exist in combination with immune checkpoint inhibitors, in earlier lines of therapy, and in the treatment of urothelial carcinoma and non-small cell lung cancer. However, the earliest marker of whether Gilead’s large investment is worthwhile will be gathered from the TROPICS-02 trial readout, which is expected later this year after Covid-19-related delays. After an initially bumpy road, Immunomedics is now at an inflection point in the company’s history, and Gilead’s acquisition provides further confidence for analysts judging the future success of this biopharmaceutical company.