Upcoming events – Corbus leans on Resunab and crunch time for Aeterna’s Macrilen

Welcome to your weekly digest of approaching regulatory and clinical readouts. Phase II data for Corbus Pharmaceuticals’ only project, Resunab, in systemic sclerosis are expected before the end of 2016. Shares have rallied since the beginning of the year, but efficacy concerns have been raised.

Meanwhile, in the new year Aeterna Zentaris will be hoping that phase III data on Macrilen, used to evaluate growth hormone deficiency, will not let it down again. The product previously received a complete response letter that rocked shares, and investors are hanging on for good news.

Hitting that high

Resunab, an oral cannabinoid receptor 2 agonist, is in a phase II trial in 42 adult patients with systemic sclerosis, an autoimmune disease characterised by chronic activation of the immune system, damage to blood vessels and fibrosis of the skin, lungs and other organs.

There is an 84-day treatment period and 28-day follow-up, testing 5mg and 20mg doses of Resunab versus placebo. The primary endpoints include adverse events and the change in CRISS, a combined response index that looks at changes in skin thickness, lung function and patient and physician global assessments.

Topline results are expected shortly, while a 12-month open-label extension study is ongoing. Resunab has US orphan drug designation for systemic sclerosis as well as cystic fibrosis, in which it is undergoing a phase II trial.

Corbus listed on the OTC bulletin board in 2014, and since then shares are up 290%, with rallies in September and the beginning of October as the data point approached. Its market cap currently sits at $282m.

However, the stock took a 29% hit towards the end of last month when an unnamed short-seller told The Street that the upcoming phase II data were unlikely to impress based on lack of efficacy in a pain trial run by a previous licence holder, though Corbus is not pursuing this indication. The latest trial needs to succeed to keep the share rally on track.

In terms of competition, the cannabinoid space is dominated by GW Pharmaceuticals, which developed the first launched product, Sativex, for multiple sclerosis spasticity. 

Second chance

Adult growth hormone deficiency is currently diagnosed by injecting the patient with insulin to induce hypoglycaemia. This spurs growth hormone secretion from the pituitary gland as part of a stress response. The level of growth hormone in the blood are then measured: if this is less than 7µg/L deficiency may be diagnosed.

Unfortunately the procedure is very dangerous thanks to the risk of sending the patient into a diabetic coma. So Aeterna Zentaris is conducting a phase III trial of Macrilen, a ghrelin agonist and growth hormone secretagogue, in 110 adults with suspected deficiency and in healthy volunteers. The trial is designed as a two-way crossover study and uses the insulin tolerance test as a diagnostic comparator.

Data are expected early next year and Aeterna intends to submit an NDA for Macrilen – despite its role in diagnosis it is regulated as a drug – in the first half of 2017.

As well as being safer Macrilen is orally administered and takes effect faster, producing results in minutes instead of three or four hours.

The company has already made one approval attempt with the product, in 2014, which culminated in a complete response letter. The FDA highlighted data deficiencies and efficacy concerns and requested a further trial, causing Aeterna’s shares to fall 50%.

Analysts from HC Wainwright & Co write that if Macrilen can prove comparable accuracy to the insulin test, it could launch in 2018 and achieve risk-adjusted revenues of $50m by 2025. With just $21m in cash the company is in need of some good news. Macrilen might not be its saving grace.

To contact the writer of this story email Joanne Fagg in London at [email protected] or follow @JoEPVantage on Twitter