Blueprint told to stop sketching as FDA slaps partial hold on phase 1/2 trial

Blueprint Medicines will have to put down its pencil for now, pausing enrollment in a phase 1/2 trial of its solid tumor med BLU-222 so the FDA can take a closer look at visual adverse events. 

The company did not disclose how many of the events occurred but said in an announcement Friday that all were grade 1 except for one grade 3 incident. The visual side effects consisted of light sensitivity and blurred vision. All events were resolved with “dose interruption or reduction,” and there have been no trial discontinuations due to the side effects, according to Blueprint.

The VELA trial launched in February 2022 to test doses of BLU-222 ranging from 50 mg up to 800 mg. Over 360 patients with solid tumors are expected to be recruited, with the grade 3 event seen in a patient who received a 600-mg dose. 

The company is working with the FDA to investigate the side effects and will also amend the VELA trial protocol to provide better guidance to investigators, Chief Medical Officer Becker Hewes, M.D., said in a release. Blueprint still expects to report initial data from the trial in the first half of the year. 

The news stunts the progress of one of Blueprint’s younger prospects as it looks to expand beyond its two launches of cancer meds Ayvakit and Roche-partnered Gavreto. BLU-222 targets CDK2, a protein kinase that works to regulate cell cycle progression and DNA replication. But, in the tumor environment, it can start to run a bit haywire, causing DNA damage.

Blueprint has yet to report its full-year earnings for 2022 but said in January that it expects to have reeled in between $180 million and $200 million in revenue. It’s also sitting on a pile of cash, with nearly $1.2 billion on hand as of the end of September. News of the hold did, however, dampen the company’s stock, with shares down 6% from a Thursday close of $44.29 to $41.64 in the opening hour of Friday.