Prevailing after an initial complete response letter from the FDA, Chiasma Inc. on June 26 has finally secured U.S. approval for Mycapssa, the first oral formulation of the acromegaly medicine octreotide to get a regulatory green light. Octreotide has until now only been available by injection. The drug was approved for long-term maintenance treatment in acromegaly patients who have responded to and tolerated treatment with octreotide or lanreotide, both somatostatin analogues (SSAs).
"We're really excited to bring this novel option into the marketplace that could potentially be the new gold standard, especially in a COVID-19 environment where patients are very reluctant to take on medically administered products," Chiasma CEO Raj Kannan told BioWorld.
Shares of the Needham, Mass.-based company (NASDAQ:CHMA) fell 1.5% to $6.47 before trading was halted Friday morning. When trading resumed, shares fell to $6.08.
Basic patent protection for octreotide has expired in the U.S., Europe and Japan. However, Mycapssa is the first FDA-approved product to make use of Chiasma's specialized bioavailability tech, which allows gastrointestinal absorption of unmodified peptides into the bloodstream.
The new medicine could be commercially available in the fourth quarter, subject to the FDA’s approval of a planned manufacturing supplement to the approved NDA, the company said. Pricing, which has yet to be disclosed, will be competitive, the company said, and “based on the unmet need and patient population.” An estimated 8,000 individuals are on injectable SSAs in the U.S., it said.
FDA approval was based on the positive results of the randomized, double-blind, placebo-controlled, nine-month phase III Optimal trial of octreotide capsules, which met the primary endpoint and all four secondary endpoints, as well as safety data from all of Chiasma’s phase III trials of Mycapssa.
Acromegaly, a chronic endocrine disorder characterized by hypersecretion of growth hormone, is almost always treated first with surgery. But for patients whose growth hormone levels don't normalize after that, pharmaceutical therapy is typically next. Novartis AG's long-acting Sandostatin (octreotide) and Ipsen SA's Somatuline (lanreotide) lead the market, having generated 2019 sales of $1.59 billion and $1.19 billion, respectively.
Pfizer Inc.'s Somavert (pegvisomant), a growth hormone receptor antagonist commonly used in patients who are refractory to treatment with either lanreotide or octreotide, has also gained traction, with $264 million in sales.
But as long-acting options have gained traction with patients, they can also bring anxiety and discomfort in some cases. The label for Sandostatin, which is administered monthly, reports that 7.7% of patients in clinical studies experienced pain on injection. Pooled clinical data on Somatuline, administered monthly using a deep subcutaneous injection, indicated 4% of patients experienced injection site pain.
Mycapssa's availability will create new competition for the already-available acromegaly therapies, but plenty of competition is on the horizon. Emerging candidates in the space include a prolonged-release formulation of Ipsen's lanreotide and the non-peptide somatostatin agonist paltusotine (CRN-00808), a once-daily oral therapy for acromegaly under development at Crinetics Pharmaceuticals Inc. Crinetics said on June 11 that more than half the patients enrolled in a phase II switching study have completed the trial. Top-line results from the trial, called Acrobat Edge, are expected in the fourth quarter. A phase III trial of the drug is expected to start in the first half of 2021.
Camurus AB is also developing a subcutaneously self-administered slow-release liquid crystal depot formulation of octreotide called CAM-2029. It was working in collaboration with Novartis until May 2018, when Novartis returned rights to the drug.