Novartis, GBT sickle cell drugs face coverage hurdles as gene therapy threats loom: survey

Novartis’ Adakveo and Global Blood Therapeutics’ Oxbryta started their commercial life in 2019 as novel drugs for sickle cell disease. While physicians like their efficacy and safety profiles, formulary coverage is a hurdle, doctors told analysts in a survey. That's not to mention potential gene therapy threats.

For both Adakveo and Oxbryta, 64% of physicians said the drugs have unfavorable cost and coverage dynamics compared with traditional hydroxyurea therapies, analysts at JPMorgan wrote in summarizing survey responses from 25 U.S. physicians. Each of the doctors sees at least 25 sickle cell disease patients.

The unfavorable coverage profiles suggest the companies still have work to do to increase access, the JPMorgan team said in a recent note to investors. Currently, many payers are requiring patients try other meds before covering the newer drugs, the analysts wrote.

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The access problem comes in contrast to the fact that most doctors view the drugs as having a better or similar clinical profile compared with hydroxyurea.

Nevertheless, about half of physicians said their overall clinical experience with Oxbryta has been worse than that with hydroxyurea. That rate was 36% for Adakveo in comparison with the older drug. The JPMorgan team labeled the results as “no surprise,” given the Novartis and GBT drugs are relatively new.

Adakveo vs. Oxbryta

Between the two new offerings, doctors generally rated Adakveo higher in terms of its ability to reduce vaso-occlusive pain episodes, which is the most important product characteristic the doctors said they look for when making therapy choices. Oxbryta scored better with respect to hemoglobulin improvement or impact on anemia.

Those responses are generally in line with the two drugs’ FDA labels.

Adakveo is an antibody drug given by infusion once a month, whereas Oxbryta is a daily oral drug. Despite their difference, dosing and convenience don’t weigh much on prescription behavior, the doctors said.

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Currently, physicians treat 60% of sickle cell patients with single-agent drugs, the survey showed. Among those patients, only 6% are on Adakveo monotherapy, while another 6% take Oxbryta. Looking forward, the outlook appears to favor the Novartis drug. Over the next three years, the physicians expect single-agent use to rise to 18% for Adakveo but only 11% for Oxbryta, while combination utilization of the drugs with other therapies will remain relatively stable.

Gene therapy could threaten growth

But the potential entry of gene therapies could become “a key barrier” to Oxbryta and Adakveo growth over the longer term. The surveyed doctors expect single-agent use of gene therapy to reach 24% of patients by 2028.

Overall, the physicians surveyed believe that a third of their sickle cell disease patients on average would be suitable for a gene therapy. Most physicians had a favorable view of the two clinical candidates, bluebird bio’s LentiGlobin and CRISPR Therapeutics and Vertex’s CTX-001.

The physicians’ feedback highlights the potential squeeze from future competition, the JPMorgan analysts said. All told, the team expects Adakveo to reach about $700 million in peak sales and Oxbryta to hit $950 million from the U.S. and EU.

COVID-19 slows launch

Like other drug launches in recent years, the pandemic has wreaked havoc on the sickle cell disease rollouts. A quarter of surveyed doctors said they'd seen a decrease in patient visits during the pandemic. In the first quarter, sales of Oxbryta reached $39 million in the U.S., compared with $37 million for Advakeo from the U.S. and EU.

RELATED: GBT chief blames COVID-19 for 'clear' slowdown in Oxbryta launch, but analysts are still impressed

Telemedicine has helped ease the negative effects from COVID-19, but doctors are less comfortable starting a new therapy without an in-person visit, GBT’s chief commercial officer, David Johnson, said during an investors’ call in May.

As two doctors observed in their response to the JPMorgan survey, they have adopted telemedicine for “very stable patients,” or “mostly for follow-ups and discussing side effects.” Looking ahead, the physicians expect to increasingly shift back to on-site visits over the next six to 12 months.