Zacks Small Cap Research – XFOR: Positive Interim Data from Ongoing Phase 2 Trial of Mavorixafor in Chronic Neutropenia Patients… – Technologist

By David Bautz, PhD

NASDAQ:XFOR

READ THE FULL XFOR RESEARCH REPORT

Business Update

Positive Interim Update for Phase 2 Chronic Neutropenia Trial

On June 27, 2024, X4 Pharmaceuticals, Inc. (NASDAQ:XFOR) held a webinar to provide an interim update for the ongoing Phase 2 clinical trial of mavorixafor in patients with chronic neutropenia (CN). The Phase 2 study is fully enrolled with 23 participants across three groups: mavorixafor monotherapy, mavorixafor + stable-dose G-CSF, and mavorixafor + G-CSF with dose-adjustments. The following table gives an overview of the participant disposition as of the cutoff date of May 14, 2024.

The target change in absolute neutrophil count (ANC) for this study was ≥ 500 cells/µL. All six participants achieved the target ANC increase by month 6, as shown in the following graph. While seven patients total completed six months of treatment, samples from one participant who completed the study were unevaluable at month six, however that individual’s data was included in the month 1 and month 3 evaluation.

For the mavorixafor monotherapy group, the following graph shows a durable increase in mean ANC across that cohort with the average ANC for the group starting in what would be considered “moderate neutropenia” and by month six the average participant exceeded the lower limit of normal.

For the mavorixafor + stable-dose G-CSF cohort, the results showed a robust increase in ANC with a mean increase of >1000 cells/µL from baseline at all timepoints. The following graph shows the normalized increase in ANC, which was utilized due to G-CSF dose/ANC variability, with ANCs at baseline ranging from ~700 cells/µL to >1500 cells/µL. We believe the large increase in mean ANC supports the potential for decreasing G-CSF dose.

In regards to safety, mavorixafor was well tolerated as both a monotherapy and in combination with G-CSF, as there were no deaths or drug-related serious adverse events reported. The most frequent adverse events were GI related (nausea and diarrhea) and there were no discontinuations following increased patient education on the potential for GI effects that typically resolve over time.

Phase 3 4WARD Study Initiated

X4 has initiated participant screening for the Phase 3 4WARD trial of mavorixafor in CN patients with congenital, autoimmune, or idiopathic chronic neutropenia. The trial is expected to enroll 150 participants with an ANC <1500 cells/mL and a history of two or more infections requiring intervention in the last 12 months. The primary endpoint is a two-component endpoint based on a positive ANC response and annualized infection rate, with secondary endpoints evaluating severity and duration of infection, antibiotic use, fatigue, quality of life, and safety.

Financial Update

In May 2024, X4 announced it completed the sale of its Rare Pediatric Disease Priority Review Voucher (PRV) for $105 million (we had modeled for $100 million). In addition, the company drew down an additional tranche of $20 million under its existing loan facility with Hercules Capital. This infusion of capital has extended the company’s cash runway into late 2025, which does not include revenues from expected commercial sales of XOLREMDI™.

Conclusion

We are encouraged by the positive interim update from the ongoing Phase 2 trial of mavorixafor in CN patients. No new safety issues were identified, 100% of patients achieved the target increase in ANC after six months of treatment, and the robust increase in ANC in patients receiving mavorixafor + G-CSF supports the potential for decreasing the G-CSF dose.

However, the one area of concern for investors may be the pace of enrollment for the Phase 3 trial (based on the enrollment rate for the Phase 2 trial), which we hope will be helped by the greater number of clinical sites across multiple countries. To be conservative, we have pushed out the expected approval date in CN by one year. This has resulted in a slight decrease to our valuation to $5.00 per share, however we believe the reaction in the stock since the interim update has been overdone and represents a nice buying opportunity for long-term investors.

SUBSCRIBE TO ZACKS SMALL CAP RESEARCH to receive our articles and reports emailed directly to you each morning. Please visit our website for additional information on Zacks SCR. 

DISCLOSURE: Zacks SCR has received compensation from the issuer directly, from an investment manager, or from an investor relations consulting firm, engaged by the issuer, for providing research coverage for a period of no less than one year. Research articles, as seen here, are part of the service Zacks SCR provides and Zacks SCR receives quarterly payments totaling a maximum fee of up to $40,000 annually for these services provided to or regarding the issuer. Full Disclaimer HERE.