Less than three months after an $111 million December offering, Global Blood Therapeutics Inc. has launched an upsized $216 million public offering that will fund two crucial studies of its hemoglobin-modulating sickle cell candidate, voxelotor, including a pivotal trial, the first part of which is expected to read out before the end of June.

Wells Fargo Securities LLC, the sole book-running manager for the offering, bought and quickly sold the shares (NASDAQ:GBT) at a profit to investors eager to bet on the company's odds for success.

"This money was really directed toward our business base case, getting it approved, getting it launched and running the business," GBT President and CEO Ted Love told BioWorld, "It puts the company in an unusually strong position, where we have enough money to run it all the way out until its essentially profitable," he said.

Shares (NASDAQ:GBT), priced at $54 each in the offering, closed at $57.15 on Friday, having risen 25 cents from their previous close.

GBT is running two key trials for voxelotor, an oral once-daily prophylactic treatment that won FDA breakthrough status in January, drawing a new wave of investor interest. The phase III HOPE (Hemoglobin Oxygen Affinity Modulation to Inhibit HbS PolymErization) study is testing it in participants ages 12 and older with sickle cell disease (SCD). Additionally, voxelotor is being studied in the ongoing phase IIa HOPE-Kids 1 study, an open-label, single- and multiple-dose trial in pediatric patients ages 6 to 17 with SCD.

Love described the HOPE study as two studies in one, with part A being akin to a large phase II study, and part B being more like a traditional phase III study expected to read out in the first half 2019. with very little pause between the two parts.

The HOPE study is designed to enroll up to about 400 adult and adolescent SCD patients who have had at least one episode of vaso-occlusive crisis, or VOCs, in the previous year. Part A, which compares two dose levels of voxelotor, 900 mg and 1,500 mg, vs. placebo, will include up to 150 patients. It will be quickly followed by part B, which will include 250 patients randomized to placebo or a dose of voxelotor selected based on the results of part A.

The main objectives of part A are to select the optimal dose, define the final secondary endpoints for part B and qualify a patient-reported outcome, or PRO, instrument. The primary efficacy endpoint is the proportion of patients who achieve a greater than 1 g/dL increase in hemoglobin at 24 weeks of treatment compared to baseline.

Key secondary efficacy endpoints of the study include the effect of voxelotor on SCD symptom exacerbation, which will be measured by the PRO instrument, in addition to overall SCD symptoms as compared to placebo. Investigators will also assess traditionally defined VOCs as well as hospitalizations and red blood cell transfusions as secondary endpoints.

GBT disclosed new results from the ongoing open-label, single- and multiple-dose study, Hope-Kids 1, in December at the American Society of Hematology (ASH) meeting. Now, Love said he expects to release more at the upcoming meeting of the European Hematology Association in June, followed by even further details at ASH 2018. The company is slowly including younger and younger children, with the goal of testing voxelotor in children as young as age 2 ahead of an NDA filing. Later, with HOPE Babies, it expects to include children as young as 9 months of age.

At ASH 2017, GBT shared data from part B of the HOPE Kids 1 study, exploring the safety of two doses of voxelotor – 900 mg and 1,500 mg per day – administered to patients ages 12 to 17, with interim results from 12 patients in the 900-mg cohort. After 16 weeks of treatment, they were found to have increased hemoglobin levels and improved clinical measures of hemolysis, as evaluated by changes from baseline in hemoglobin, percent of reticulocytes and percent of unconjugated bilirubin. The results were consistent with results previously seen in adults, even though nearly all of the adolescent patients were also receiving hydroxyurea, the company said. Specifically, 55 percent of patients, or six of the 11 patients for whom data were available at 16 weeks, achieved a hemoglobin response of greater than 1 g/dL with a median hemoglobin change of 1.1 g/ dL. The cohort evaluating the 1,500-mg dose is ongoing.

Regulatory recognition for the SCD program has been strong. To date, GBT has secured FDA fast track, orphan drug and breakthrough therapy status for voxelotor in SCD, as well as a rare pediatric disease designation. It has also landed EMA orphan status and a spot in the regulator's priority medicines, or PRIME, program.

As it pushed ahead to a presumptive 2019 filing, it is already preparing its commercial organization, hiring Gilead Sciences Inc. veteran David Johnson as its chief commercial officer. Love said that Johnson's experience launching both HIV and hepatitis products is highly relevant to GBT since both conditions affect the African-American community, a group that has been disproportionately affected by SCD.

Voxelotor, formerly known as GBT-440, had once been in development for the potential treatment of idiopathic pulmonary fibrosis, too, but GBT discontinued that program in October after three proof-of-concept studies failed to demonstrate sufficient overall clinical benefit.