Tuesday, May 29, 2012

Celldex's triple-negative breast cancer progress

Triple-negative breast cancer (TNBC) is a nasty form of the disease that does not respond to receptor-targeted therapeutics (Herceptin or Tamoxifen), as the receptors of interest (estrogen (ER), progesterone (PR), or HER-2) are not found in TNBC. The only marginally-effective treatments against TNBC are general chemotherapies, but overall response and survival rates are much lower in TNBC versus other breast cancers.

Celldex (CLDX) released P2B results from a clinical trial using their drug (CDX-011) in TNBC. Results suggest that the Celldex drug works against triple-negative cancers that overexpress a protein known as GPNMB. Celldex reports that 36% of patients with TNBC and high GPNMB expression responded to CDX-011, while zero patients in the equivalent control groups responded to standard chemotherapies. (N=11 and 3 respectively, so let's not overreact.)

(Also: NON-TNBC patients with high GPNMB expression showed a response to CDX-011. (32% response vs. 13%. N=25 and N=8, respectively.

Adding these two groups together yields a response in 15 of 36 patients (42%!) with high GPNMB expression treated with CDX-011, with 1 responder of 11 in the control group. (i.e. not treated with CDX-011.)

This data is encouraging for Phase 2B, and warrants a Phase 3 trial AND a large pharma partner, something I would expect to see Celldex close on by the end of 2012. (TNBC sometimes responds to EGFR treatment, so I'd expect Celldex's partner to be a company with an EGFR product interested in prescribing a combination of products. (Hello, AMGN, and Roche!)

(Speaking of combination, CDX-011 uses Seattle Genetics' antibody linked technology, whereby the antibody with affinity to GPNMB delivers a chemo payload to the cancerous cell. I need to take another look SGEN soon.)

CLDX Financial overview, as of 5/28/12:
Market cap: $264M (even after popping ~10% on the tnbc trial news
Cash on hand: $92M, burning ~$40M/yr.
Enterprise value: $172M
ex-CDX-011 enterprise value: $35M-$50M, as CLDX receives $9M/year in license income from successful outlicensing.
CDX-011 value (roughly): $130M ($172M less $42M in ex-CDX-011 enterprise value ($42M= midpoint of $35M-$50M valuation.)

What's the value of CDX-011?

CDX-011 Market math:
CLDX asserts that 35% of all breast cancer patients could benefit from CLDX-011, which suggests:

Annual US breast cancer cases: ~180,000
% of breast cancer that is TNBC: 15-25% via various sources. Let's say 20%.
US TNBC market: 36,000
GPNMB overexpressers as a %age of TNBC patients: 12% of TNBC, or 4,320

US GPNMB market:27,000
non-TNBC patients overexpressing GPNMB: 15% of all breast cancers
US market for GPNMB overexpressors (w/o TNBC): ~27,000 
Likely US GPNMB+ market: 31,320 annually, and therefore,
Total annual world market for CDX-011: between 80,000 and 120,000 patients worldwide.

Assuming $20k revenue/patient ($50k/patient revenue, but only 40% penetration at peak), CDX-011 would then peak at ~$2B/yr in revenue, and therefore peak product value of ~$12B (equivalent to Celgene's 6X sales valuation.)

Risk-adjustment of CDX-011 value: let's assume the following:
-that FDA approval is 2 years away,
-peak revenue is 4 years post-approval
-25% discount rate
-CDX-011 has a 40% chance of successful P3 trials....

Based on peak market value of $12B for CDX-011, you could then project that CDX-011 has a present value of $1.25B, or, with a current valuation for CLDX of $172M, that the market thinks that there is only a 14% chance that my scenario above becomes true. Either way, the likelihood that Celldex is undervalued is high.

(btw: is use the value of CLDX and CDX-011 interchangeably. While CLDX does have other products in the pipeline, 99% of CLDX valuation will depend on CDX-011.)

(CLDX says that 35% of breast cancer patients could benefit from targeting GPNMB with CDX-011. It's probably a rosy-case press release figure, but even if you chop this number in half, the resulting NPV for CDX-011 3.6X today's valuation.)

Factors for Celldex:
1) Few, if any, other GPNMB programs in existence, so it is a seller's market (when it comes to partnering) for Celldex.
2) There's plenty of reason to expect CLDX to partner CDX-011 soon, and it's an ideal time to partner - P3 trials costs are significant and therefore better shared with a partner, plus partnering now allows the Big Pharma partner to influence trial design.
3) CDX-011 clinical responses exceed the 30% hurdle rate and in P2B trials have a wide advantage versus the control arm. (I'm always skeptical if the response rate and advantage versus control group outcomes is <=20% and <=10%, respectively.)
4) Good sized market, not currently served.

Factors against Celldex:
1) small-cap biotechs NEVER successfully get drugs to the market by themselves.
2) ultimate FDA approval may be conditional for GPNMB+ only, and also could depend on the development of a gene-specific test.
3) lack of partner to date could represent Big Pharma skepticism over either GPNMB's target biology or Celldex's capabilities.
4) Limited ability to raise equity financing.
5) small sample size in P2B results.
6) time to FDA approval of ~2yrs limits the ability to buy call options for CLDX.

Ultimately, the value of CLDX is driven by 1) CDX's long term outlook, and 2) the size and timing of a partnership with a big pharma to commercialize CDX-011. Outlined above is one long-term scenario representing a win for CLDX, and for the other point (partnership value), I can easily see CLDX doubling the company's valuation this year after consumating a big pharma partnership centered on CDX-011. (Guess: $50M cash @ closing, $50M in equity purchased by the pharma partner, with $1B in milestones possible; also: $50M in easily achievable milestones to land in the first 12 months. (example: $25M payment at initiation of P3 trials.)

Here's hoping that CDX-011 lives up to the P2B results, and that finally we'll have a weapon against TNBC.

Disclosure: at the time of writing, I DO hold a tiny position in Celldex.

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