Asco 2021 – Abstract lift drives first stock moves

The unveiling of the Asco abstracts is one of the biggest events of the year for followers of oncology stocks and, despite going virtual for the second year running, 2021 looks set to deliver its fair share of crucial updates. 

Much of the most important data remains under wraps, however, with late breaking abstracts due to be release at 5pm ET on June 3, the day before the meeting gets under way. Small cap developers have delivered the sharpest share price rises so far, with Sensei and PDS jumping 30% and 27% on largely incremental updates. Meanwhile Merus’s bispecific update failed to excite, with the stock ending up down 16%. 

First to the risers, with newly-listed immuno-oncology player Sensei getting a boost from data from an ongoing trial of its lead asset in head and neck cancer. SNS-310 is an inactivated bacteriophage virus expressing ASPH, an antigen that Sensei says is over-expressed in several tumour types. 

A poster presentation will detail responses in 12 patients who failed to respond to PD-1 blockade, with a 67% (8/12) response rate, including one partial response and seven cases of stable disease. 

Despite the share price jump to $12.66 Sensei stock remains well below the $19 at which it floated in January. PDS stock, meanwhile, is now trading at its highest level since the company reversed into a failed biotech back in March 2019, thanks to data being generated by an NCI-led study of the company’s lead project, PDS0101. 

A triple combination of PDS0101 and two Merck KGaA assets – the IL-12 asset M9241 and TGF-β/PD-L1 fusion protein bintrafusp alfa – is being trialled in patients with refractory HPV16-associated cancers. The abstract details a 71% (10/14) ORR, with one complete response and nine partials, although a later cut of the data is expected at the conference. 

Other risers yesterday included Lag3 developer Immutep, which is presenting three posters at the conference containing updates from ongoing trials of eftilagimod alpha. The stock jump yesterday, taking the Australian developer to a six-year high, was more to do with Bristol Myers Squibb’s success with its Lag3 asset, relatlimab.

Merus was not the only faller yesterday, with Alpine Immune and Black Diamond Therapeutics also nursing losses, down 17% and 37% respectively. 

One unconfirmed partial response among 11 evaluable subjects from Alpine’s CD28 costimulator and dual checkpoint inhibitor, ALPN-202, failed to impress. Dose escalation continues, however.

Black Diamond meanwhile is targeting intractable tumour types driven by various EGFR or HER2 mutations. At the maximum tolerated dose for once-a-day pill BDTX-189 generated two partial responses, only one of which was confirmed, three cases of stable disease and progressive disease in 10 subjects. 

Enrolment in other dosing cohorts is ongoing but these data were a big disappointment from another of 2021’s IPO cohort. The stock is now trading 17% below its float price, with yesterday’s plunge erasing $300m from the company’s market cap. 

This is far from an exhaustive review of notable presentations, of course, and with much more data due in the coming weeks, the Asco trading period is far from over.