As Merck buyout buzz heats up, Seagen touts a positive update on their Padcev/Keytruda combo
Most of the news at Seagen these days revolves around hot buzz about a potential $40 billion-plus Merck buyout. But today the focus has shifted to an experimental combo that uses the pharma giant’s big PD-1 cancer drug Keytruda.
Execs at Seagen and their partner Astellas posted positive top-line numbers for a combination of Padcev and Keytruda, noting a confirmed overall response rate of 64.5% for frontline urothelial cancer patients who are ineligible for cisplatin.
Median duration of response had not yet been achieved.
This was the EV-103 Cohort K expansion trial, which saw a dip in the ORR rate from the 73% tracked in Cohort A. But several analysts today were quick to offer the results at least a tentative thumbs-up, while noting that a number of questions have to be answered before they can fully determine the combo’s value.
Andrew Berens at SVB Securities took a look at the data and noted:
We believe the results were generally expected to come down in larger patient numbers, but still came in above what we viewed as the bar for success (ORR in the low 60%’s). Median duration of treatment was unreached, and treatment exposure in the trial was not disclosed. More importantly, median cycles of Padcev usage were unreported, a key metric given that peripheral neuropathy appears to limit usage of Padcev in some settings, and is likely cumulative.
Berens came up with his own set of outstanding questions.
(T)he announcement was sparse on key efficacy details like: 1) duration of Padcev usage (number of cycles); 2) durability metrics (median duration of response [DOR] not reached), and 3) the efficacy of Padcev monotherapy arm. We think that the absence of inclusion of the monotherapy data in the press release suggests the activity/duration is likely meaningfully less than combination, important to some investors speculating on the likelihood of optionality, which would be largely driven by synergies with checkpoint agents.
Padcev is Seagen’s second best-selling drug, with $340 million in sales last year. Company execs have been focused on this new combo trial as a major catalyst for bigger sales ahead, if they can parlay the data into an accelerated approval. But the jury is still out on that score.
Count Boris Peaker at Cowen, though, as another interested onlooker. He’s ready to give the combo solid odds for an approval in the early part of next year, pushing franchise revenue to $665 million next year.
“Approximately half of patients with advanced urothelial carcinoma are ineligible for cisplatin-based chemotherapy,” said Ahsan Arozullah, SVP and head of development therapeutic areas at Astellas, in a press release. Cisplatin-ineligible patients typically have few treatment options and a poor prognosis.
Padcev is the first antibody-drug conjugate of its kind, the pair says, and works by attaching itself to Nectin-4, a cell surface protein highly expressed in bladder cancer. A specific chemotherapy agent is then released to kill the cells. The companies will discuss the results with regulatory authorities.
Meanwhile, Merck is in advanced talks to buy Seagen for about $40 billion or more, or above $200 per share, according to Wall Street Journal reports. The latest word from the Journal was that any move would likely come after their earnings call July 28. If the deal goes through, it could be one of the biggest transactions in recent history.