Mavorixafor, an Orally Bioavailable CXCR4 Antagonist, Increases Immune Cell Infiltration and Inflammatory Status of Tumor Microenvironment in Patients with Melanoma.

Mavorixafor is an oral, selective inhibitor of the CXCR4 chemokine receptor that modulates immune cell trafficking. A biomarker-driven phase Ib study (NCT02823405) was conducted in 16 patients with melanoma to investigate the hypothesis that mavorixafor favorably modulates immune cell profiles in the tumor microenvironment (TME) and to evaluate the safety of mavorixafor alone and in combination with pembrolizumab. Serial biopsies of melanoma lesions were assessed after 3 weeks of mavorixafor monotherapy and after 6 weeks of combination treatment for immune cell markers by NanoString analysis for gene expression and by multiplexed immunofluorescent staining for in situ protein expression. Serum samples taken at biopsy timepoints were evaluated for key chemokine and cytokine alterations using the Myriad Rules Based Medicine multiplex immunoassays. Within the TME, mavorixafor alone increased CD8+ T-cell infiltration, granzyme B signal, antigen presentation machinery, and both tumor inflammatory signature (TIS) and IFNγ gene expression signature scores. Increases in the key serum cytokines CXCL9 and CXCL10 were further enhanced when mavorixafor was combined with pembrolizumab. Adverse events (AE), as assessed by the investigator according to NCI Common Terminology Criteria for Adverse Events (v4.03), related to either mavorixafor or pembrolizumab (≥15%) were diarrhea, fatigue, maculopapular rash, and dry eye. Reported AEs were all ≤ grade 3. Treatment with single-agent mavorixafor resulted in enhanced immune cell infiltration and activation in the TME, leading to increases in TIS and IFNγ gene signatures. Mavorixafor as a single agent, and in combination with pembrolizumab, has an acceptable safety profile. These data support further investigation of the use of mavorixafor for patients unresponsive to checkpoint inhibitors. Despite survival improvements in patients with melanoma treated with checkpoint inhibitor therapy, a significant unmet medical need exists for therapies that enhance effectiveness. We propose that mavorixafor sensitizes the melanoma tumor microenvironment and enhances the activity of checkpoint inhibitors, and thereby may translate to a promising treatment for broader patient populations.

Andtbacka RHI ，Wang Y ，Pierce RH ，Campbell JS ，Yushak M ，Milhem M ，Ross M ，Niland K ，Arbeit RD ，Parasuraman S ，Bickley K ，Yeung CC ，Aicher LD ，Smythe KS ，Gan L ... -  《-》

A phase 1b trial of the CXCR4 inhibitor mavorixafor and nivolumab in advanced renal cell carcinoma patients with no prior response to nivolumab monotherapy.

Background The CXCR4 chemokine receptor promotes tumor survival through mechanisms that include suppressing antitumor immune responses. Mavorixafor (X4P-001) is an oral, selective, allosteric CXCR4 inhibitor that decreases the recruitment of immunosuppressive cells into the tumor microenvironment and increases activated cytotoxic Tcell infiltration. Methods Patients with metastatic clear cell renal cell carcinoma (ccRCC) unresponsive to nivolumab monotherapy received oral mavorixafor 400 mg daily plus 240 mg intravenous nivolumab every 2 weeks. Results Nine patients were enrolled, median age 65 years. At baseline 4 had progressive disease (PD) and 5 had stable disease (SD). One of 5 patients with SD at study entry on prior nivolumab monotherapy had a partial response (PR) on combination treatment; all 4 patients with PD at study entry had a best response of SD with the combination treatment (median duration: 6.7 months; range: 3.7-14.7). Four patients discontinued therapy due to treatment-related adverse events (AEs). Grade ≥ 3 drug-related AEs were elevated alanine and aspartate aminotransferase (2 patients each); and autoimmune hepatitis, chronic kidney disease, increased lipase, maculopapular rash, and mucosal inflammation (1 patient each). A robust increase in levels of chemokine (C-X-C motif) ligand 9 CXCL9 on mavorixafor appeared to correlate with clinical benefit. Conclusions The CXCR4 inhibition mediated by mavorixafor, in combination with PD-1 blockade to enhance antitumor immune responses in patients unresponsive to checkpoint inhibitor monotherapy, is worthy of further study. Mavorixafor and nivolumab combination therapy in patients with advanced ccRCC demonstrated potential antitumor activity and a manageable safety profile.Trial registration: ClinicalTrials.gov identifier: NCT02923531. Date of registration: October 04, 2016.

Choueiri TK ，Atkins MB ，Rose TL ，Alter RS ，Ju Y ，Niland K ，Wang Y ，Arbeit R ，Parasuraman S ，Gan L ，McDermott DF ... -  《-》

Results of a phase 2 trial of an oral CXCR4 antagonist, mavorixafor, for treatment of WHIM syndrome.

Warts, hypogammaglobulinemia, infections, and myelokathexis (WHIM) syndrome is a rare primary immunodeficiency caused by gain-of-function mutations in the CXCR4 gene. We report the safety, tolerability, pharmacokinetics, pharmacodynamics, and preliminary efficacy of mavorixafor from a phase 2 open-label dose-escalation and extension study in 8 adult patients with genetically confirmed WHIM syndrome. Mavorixafor is an oral small molecule selective antagonist of the CXCR4 receptor that increases mobilization and trafficking of white blood cells from the bone marrow. Patients received escalating doses of mavorixafor, up to 400 mg once daily. Five patients continued on the extension study for up to 28.6 months. Mavorixafor was well tolerated with no treatment-related serious adverse events. At a median follow-up of 16.5 months, we observed dose-dependent increases in absolute neutrophil count (ANC) and absolute lymphocyte count (ALC). At doses ≥300 mg/d, ANC was maintained at >500 cells per microliter for a median of 12.6 hours, and ALC was maintained at >1000 cells per microliter for up to 16.9 hours. Continued follow-up on the extension study resulted in a yearly infection rate that decreased from 4.63 events (95% confidence interval, 3.3-6.3) in the 12 months prior to the trial to 2.27 events (95% confidence interval, 1.4-3.5) for patients on effective doses. We observed an average 75% reduction in the number of cutaneous warts. This study demonstrates that mavorixafor, 400 mg once daily, mobilizes neutrophil and lymphocytes in adult patients with WHIM syndrome and provides preliminary evidence of clinical benefit for patients on long-term therapy. The trial was registered at www.clinicaltrials.gov as #NCT03005327.

Dale DC ，Firkin F ，Bolyard AA ，Kelley M ，Makaryan V ，Gorelick KJ ，Ebrahim T ，Garg V ，Tang W ，Jiang H ，Skerlj R ，Beaussant Cohen S ... -  《-》

A phase 3 randomized trial of mavorixafor, a CXCR4 antagonist, for WHIM syndrome.

We investigated efficacy and safety of mavorixafor, an oral CXCR4 antagonist, in participants with warts, hypogammaglobulinemia, infections, and myelokathexis (WHIM) syndrome, a rare immunodeficiency caused by CXCR4 gain-of-function variants. This randomized (1:1), double-blind, placebo-controlled, phase 3 trial enrolled participants aged ≥12 years with WHIM syndrome and absolute neutrophil count (ANC) ≤0.4 × 103/μL. Participants received once-daily mavorixafor or placebo for 52 weeks. The primary end point was time (hours) above ANC threshold ≥0.5 × 103/μL (TATANC; over 24 hours). Secondary end points included TAT absolute lymphocyte count ≥1.0 × 103/μL (TATALC; over 24 hours); absolute changes in white blood cell (WBC), ANC, and absolute lymphocyte count (ALC) from baseline; annualized infection rate; infection duration; and total infection score (combined infection number/severity). In 31 participants (mavorixafor, n = 14; placebo, n = 17), mavorixafor least squares (LS) mean TATANC was 15.0 hours and 2.8 hours for placebo (P < .001). Mavorixafor LS mean TATALC was 15.8 hours and 4.6 hours for placebo (P < .001). Annualized infection rates were 60% lower with mavorixafor vs placebo (LS mean 1.7 vs 4.2; nominal P = .007), and total infection scores were 40% lower (7.4 [95% confidence interval [CI], 1.6-13.2] vs 12.3 [95% CI, 7.2-17.3]). Treatment with mavorixafor reduced infection frequency, severity, duration, and antibiotic use. No discontinuations occurred due to treatment-emergent adverse events (TEAEs); no related serious TEAEs were observed. Overall, mavorixafor treatment demonstrated significant increases in LS mean TATANC and TATALC, reduced infection frequency, severity/duration, and was well tolerated. The trial was registered at www.clinicaltrials.gov as #NCT03995108.

Badolato R ，Alsina L ，Azar A ，Bertrand Y ，Bolyard AA ，Dale D ，Deyà-Martínez À ，Dickerson KE ，Ezra N ，Hasle H ，Kang HJ ，Kiani-Alikhan S ，Kuijpers TW ，Kulagin A ，Langguth D ，Levin C ，Neth O ，Olbrich P ，Peake J ，Rodina Y ，Rutten CE ，Shcherbina A ，Tarrant TK ，Vossen MG ，Wysocki CA ，Belschner A ，Bridger GJ ，Chen K ，Dubuc S ，Hu Y ，Jiang H ，Li S ，MacLeod R ，Stewart M ，Taveras AG ，Yan T ，Donadieu J ... -  《-》

Intratumoral interferon-gamma increases chemokine production but fails to increase T cell infiltration of human melanoma metastases.

Mauldin IS ，Wages NA ，Stowman AM ，Wang E ，Smolkin ME ，Olson WC ，Deacon DH ，Smith KT ，Galeassi NV ，Chianese-Bullock KA ，Dengel LT ，Marincola FM ，Petroni GR ，Mullins DW ，Slingluff CL Jr ... -  《-》