8 weeks for Neon to get one of its vaccines to a patient. CAR-T developers have been trying to shave days off their production time. Every minute counts with patients whose advanced cancers are moving fast.
Asked about Neon’s eight-week turnaround, O’Dowd said the company plans to make “marked reductions” this year alone. “These are cancer patients, we want to drive the therapy as fast as feasible and we’re motivated to do so,” he says.
Both Neon and Gritstone raised more than $100 million in private funding before going public in 2018. With today’s news, Neon is the first to report significant efficacy data; Gritstone and Genocea should follow by the end of 2020. Others have tests underway as well.
The key statistic for Neon officials is progression-free survival (PFS), or how long tumors were held in check for patients who received Opdivo and NEO-PV-01. After a median 13.4 months of follow-up, more than half of a group of 34 patients with advanced melanoma were still progression-free; that is, their disease hadn’t spread.
For participants with lung and bladder cancer, their tumors were held in check for a median of 5.6 months before they began to grow again. (The median follow-up for the lung patients was 12 months, and 14.7 months for the bladder patients.)
Neon says that in all cases, these numbers are superior to historical PFS benchmarks for checkpoint inhibitors alone. Neon cites several studies of checkpoint inhibitors used alone to treat skin, lung, and bladder cancer. In those studies, the checkpoint monotherapy kept tumors from spreading for a median of 3 to 7 months in melanoma patients; in lung and bladder cancers, anywhere from 2 to 4 months.
Neon’s president of R&D Richard Gaynor said Neon tried to match its trial against studies of patients with similar baseline characteristics. That’s “imperfect,” he acknowledged, but “we think we can get a good measure of similar patient groups.”
“Seeing a consistency in all three [groups] is what’s garnering our enthusiasm,” O’Dowd said. There were no serious safety issues tied to the vaccine.
Comparing the numbers to older studies wasn’t all beneficial to Neon. Its combination didn’t produce significantly higher response rates. That is, roughly the same percentage of patients, 47 and 44 percent, showed some kind of benefit, even if temporary, in the Bristol Checkmate-067 study that Neon cites.
For Neon Phase 1 participants with bladder cancer and non-small cell lung cancer, there was similar parity with previous studies. Gaynor said response rates are judged by radiologic images, which don’t capture “the full picture of what the vaccine is doing.”
“The data are in-between a slam dunk and something where you’d say, ‘This looks just like’” monotherapy with a checkpoint inhibitor, Ott said. “There may be something there.”
Neon will try to show just that. It will move NEO-PV-01 into randomized trials and try for clearer answers. The first will be a Phase 2 study of NEO-PV-01 in a subset of newly diagnosed advanced melanoma patients, O’Dowd said. (Other early stage, open label studies are underway, as well, including a test combining the NEO-PV-01 with chemotherapy and Keytruda, the current standard of care for many lung cancer patients.)
“We think there is a signal here that is encouraging enough to explore in Phase 2,” Gaynor said.
Here’s more on the emerging field of neoantigen vaccines, and the challenges that lay ahead.
