Bellus hosted their Chronic Cough KOL meeting this morning. It was paneled by:
- Jacky Smith: lead investigator of Bellus Phase 2 trials
- Denis Garceau: Bellus VP of Drug Development
- Darren Eskow: Managing Director of Blue Star Bioadvisors, life science market research firm
Below are the key takeaways from today’s call.
1. P2X3 is Best Mechanism for Chronic Cough
Companies developing other mechanisms targeting chronic cough have failed. This includes GlaxoSmithKline’s TRP modulator, NK-1 antagonists like NeRRe and Menlo (discussed here) and the most recent nAChR failure by private company Attenua.
Only companies in the P2X3 drug class (top right quadrant, below) have presented supportive data in chronic cough. These companies include the current leader Merck, Shionogi, Bayer and Bellus.
Bayer is conducting two Phase 1/2 proof of concept trials for two different compounds, BAY1817080 and BAY1902607. Both studies are expected to be completed by Q3 2019, so there should be data sometime in Q4 2019. Bayer’s readout will include cough count data and act as a catalyst for Bellus because it could further validate the mechanism of selective P2X3 drugs, discussed below.
2. Selective P2X3 Drugs Showing (Early) Comparable Effect on Cough Reduction
One of the main questions surrounding selective P2X3 companies like Bellus, Bayer and Shionogi is whether the higher selectivity will show a comparable cough decline to Merck. These selective drugs are able to inhibit the P2X3 cough receptor, but not the cousin P2X2/3 taste receptor.
Merck’s gefapixant showed a statistically decline in cough count, but had taste side effects (read details here). It is believed that Merck’s gefapixant inhibited both cough/taste receptors- which is why it reduced cough and killed taste.
However, it is unclear whether targeting only P2X3 (and not the cousin taste receptor P2X2/3) will show comparable cough reduction without the effect on taste.
Shionogi’s Phase 2 P2X3 candidate is believed to be 173x more selective for P2X3 vs P2X2/3 (compared to Merck’s candidate at 7x). Shionogi’s Phase 2 data provided further validation that a selective P2X3 will comparably reduce cough to Merck’s candidate.
Bayer’s candidate is ~125x more selective for P2X3 vs P2X2/3. The expected data readout in Q4 2019 could further prove this point. Positive Bayer data will position Bellus to be the potential best in class drug as their candidate is about 1500x more selective for P2X3.
3. Bellus on Schedule to Report Phase 2 by Mid-2020
Bellus’ Phase 2 crossover study is expected to enroll ~65 patients across 12 trial sites in the US/UK. Recruitment in the US has started and in the UK it’s expected to start by early-August. Bellus expects the first patient to be dosed within the next month.
4. Chronic Cough Market Is Huge & Can Support Multiple Players
Bellus’ primary addressable population is ~2.6M Americans that have had unexplained cough for longer than 1 year. The secondary addressable population is much larger, with about 9.1M Americans that have refractory cough for longer than 8 weeks, but less than 1 year. The treatment and symptoms for these two populations are similar.
Market research firm Blue Star Bioadvisors believes that pricing for a chronic cough product could be between $300-$400/month. Chronic cough treatment is suspected to be long term, so patients will need to stay on the drug chronically. In a small sample size, when patients came off Merck’s drug, the cough at least partially returned.
The chronic cough market is projected to be multi-billion dollar market. It has at least 2M people that will need a potentially chronic treatment. We believe the market can easily sustain the 4 existing P2X3 players, and more.
5. Plan to Develop Pipeline Outside of Chronic Cough
The hyper-sensitization of the P2X3 receptor is linked to several other indications, primarily dealing with irritation and pain. As a result, inhibiting P2X3 receptors has a broad therapeutic potential. Merck validated this same sentiment during their Investor Day Call in June (details here).
Bellus disclosed that they are currently in preclinical studies for a new indication outside of cough. The company will publicly disclose the indication upon completion of preclinical studies. Because this new indication will be using the same BLU-5937 molecule, Bellus may move directly from IND into Phase 2. The company hinted at having a planned Phase 2 in a new indication by mid-2020, the time they readout cough data.
PropThink contributors are LONG BLUSF
Access This Content Now
Sign Up Now!
