Healthcare Business

Why ArQule's Early-Stage Hematology Study Could Be Transformational

ArQule Inc. (NASDAQ: ARQL) shares jumped early on Friday after the firm announced preliminary results from an early-stage study in patients with relapsed or refractory hematologic malignancies at the 2019 European Hematology Association (EHA) annual meeting in the Netherlands.

Specifically, the results are from the company’s Phase 1 dose escalation study for ARQ 531, an orally bioavailable, potent and reversible dual inhibitor of both wild type and C481S-mutant Bruton’s tyrosine kinase (BTK).

The reported data are from the ongoing Phase 1 study in patients with relapsed or refractory chronic lymphocytic leukemia (CLL), small lymphocytic leukemia (SLL), Richter’s transformation, Waldenström macroglobulinemia and other B-cell non-Hodgkin lymphomas.

Key findings presented include:

  • ARQ 531 is well-tolerated through 65 mg QD
  • Pharmacokinetic data demonstrate a steady-state mean Cmin of above 1 µM in patients receiving ≥45 mg QD. The plasma half-life ranges from 20-30 hours
  • Pharmacodynamic data at doses above 20-30 mg QD is associated with complete pBTK inhibition and substantial CCL3 suppression
  • Robust, dose-dependent, anti-tumor activity was observed
  • ORR of 66% (4 responses in 6 evaluable patients) was observed in heavily pretreated R/R CLL patients, all with the BTK-C481S mutation, from cohort 7
  • A partial response was observed in the first patient with Richter’s Transformation, who had progressed on ibrutinib and R-CHOP, suggesting that ARQ 531’s distinct MOA is amenable to target this highly unmet medical need
  • A Follicular Lymphoma patient remains a confirmed PR and has been on therapy approximately two years, providing valuable initial insights into long- term safety as well as durability of response

Dr. Brian Schwartz, chief medical officer of ArQule, commented:

The profile of ARQ 531 continues to strengthen, and we are delighted to be able to demonstrate such compelling clinical activity at a well-tolerated dose in patients who have already exhausted available therapies. We are now focused on finalizing the recommended phase 2 dose and planning for the expansion of our clinical efforts with ARQ 531 into later stage trials across multiple indications as a single agent and as a combination therapy.

Shares of ArQule closed Thursday at $6.29, in a 52-week range of $2.23 to $7.93. The consensus price target is $9.44. The stock was up about 41% at $8.90 shortly after Friday’s opening bell.