X4 Pharmaceuticals, Inc. Common Stock Wells Fargo 21st Annual Healthcare Conference

Good to see you, Derek, and thank you for the invite.

Yeah. We're a Boston-based company that works in the area of rare hematologic disease. We're currently developing for a second indication, a drug called mavorixafor, which is a drug that increases the neutrophil counts in patients where they have conditions such as chronic neutropenia, where there are low neutrophil counts. We have a phase III that's nearing the end of enrollment called the 4WARD trial. On Monday we announced a sample size readjustment with the FDA, and the sample is now going to be 126 patients, which we aim to complete that enrollment by the end of the year.

Yeah. We came in as the new management team a year ago, so we're still learning. We learned a lot in the last year. Initially, we did get the impression the trial was overpowered. There were two endpoints. One is a reduction in infection, and the other endpoint is an increase in neutrophil count. As the year progressed and we learned more about the trial, we decided to take another look at the powering. We got our statisticians to look at it, and we worked out that we could enroll a answer the question about whether the drug works in that setting, but we could answer the question with a smaller number of patients. The benefits of that, obviously you don't want to over-enroll a trial with patients and put them on a trial unless they need to. Also, there's significant financial savings.

We ended up with a number of 126, and we ran that by the FDA. We requested a Type C meeting, and we got written comments back from the FDA. They were happy with that. The study was adequately powered at that number. We canceled the meeting, and we announced it to the street on Tuesday morning, and we're moving forward with that number. I'm pleased to say that having recently changed our CRO, who we had some problems with, we've now got Parexel in place. We've got very good enrollment at the moment, a good number of patients in screening, and we are confident that we will complete enrollment by the end of the year.

Yeah. All along, even before we joined the company a year ago, they've always been very conservative assumptions based on for the 4WARD trial. We've kept those assumptions, but what we've done is by reducing sample, reduce the powering in each of the endpoints. So the infection endpoint has 88% powering and the ANC endpoint has 93%. That's a little lower. I think it was 96% plus previously. So that's a little lower, but still very well powered for a phase III trial. But the actual fundamental example, the fundamental assumptions of the trial have not changed, and they have always been conservative.

Yeah. That was the second question. Whenever you go to the agency, you should always ask, do you have enough patients for a safety database? We have over 500 patients who have received mavorixafor, healthy volunteers and patients, and the agency didn't indicate that we didn't have enough. They said it would be a review issue, which in agency speak is, "It's okay, but we need to take a look at it.

Yeah. We are in triple digit enrollment. I am not going to give a specific number, but you can see we are in a healthy position. I think the thing that we have noticed most recently with the change in the CRO is an increase in number of patients in screening. Obviously that indicates the patients go through screening before they are enrolled, and it is really healthy, the number of patients in screening at the moment, which is very encouraging. I am pleased to say we have got patients we have enrolled, and we have got patients from the U.S. in screening as well. When we joined the company over just a year ago, there were no U.S. patients on the trial, which we were not happy with. We are now getting enrollment in the U.S., and we are getting new patients being screened in the U.S.